AudioNervosa

Self Medicating => General DIY => Topic started by: richidoo on February 04, 2012, 04:00:22 PM

Title: Econowave Speakers
Post by: richidoo on February 04, 2012, 04:00:22 PM
Inspired by the late Zilch from audioKinesis, and so many happy builders of his designs, I am building a pair of Econowave speakers to find out what's all the hubbub.

Shane's curiosity was piqued by the hundreds of thousands of posts on several different forums about this concept, so he offered to sponsor the research. Parts arrived today, scattered all over my living room like Christmas morning.

In the next few days I'll pull together a cabinet design from the ideas I have been kicking around, and get something built.

I intend to build two speakers. This first will be a straight up Econowave Delite, per the exact recipe laid out here:
http://techtalk.parts-express.com/showpost.php?p=1637407&postcount=188
The second will be fancier, but only if I like the sound of this one.

I have 4 Eminence Deltalite II 2512s from my previous DIY speaker build, so I will recycle those for this project.

The intention at this point is to build a floorstanding, bass reflex speaker with either one woofer, or two woofers for a 2.5 way.
Title: Re: Econowave Speakers
Post by: eleazar on February 04, 2012, 04:16:19 PM
You've got me thinking about trying a speaker project this spring. I'll be keeping my eyes on your project
(http://www.psd-dude.com/tutorials/the-night-of-the-halloween-killer-pumpkin/pumpkin73.jpg)
Title: Re: Econowave Speakers
Post by: jianghai on February 04, 2012, 09:17:52 PM
Looks amazing. How I wish I had some DIY chops
Title: Re: Econowave Speakers
Post by: richidoo on February 13, 2012, 01:53:24 PM
OK, time to get the ball rolling.  Thanks to Hometheaterdoc for sponsoring the "research." The aim is to find a recipe to meet his high standards of refinement and mine for power and value.

This is the first speaker we're gonna try. Loosely based on Zilch's EWave Delite, with box optimized for the Eminence DeltaLiteII 2512 woofer. Zilch's boxes were never optimimized for performance, only for price. But a whole sheet of plywood costs less than his universal knock down box, so might as well optimize the bass alignment. 131 liters makes max flat reflex alignment at the driver's resonance of 38Hz. 2 big ports keep the noise down, since they are firing forward.

(http://www.audionervosa.com/MGalleryItem.php?id=1189)

It has Qtc of .57 when the ports are sealed, so we can play with Linkwitz transform. 1 sheet of plywood for each speaker. Mitered edges to try to make it look nice. Glued bracing beams inside (diagonal lines.)  Acoustic damping inside, but maybe not cabinet resonance damping. Crossover parts fit in a separate box on the bottom.
Title: Re: Econowave Speakers
Post by: Inscrutable on February 18, 2012, 01:04:39 AM
Oooooh .... getting excited about this.  In my screenwall rebuild I am going with an AT screen, and I've been looking at various kits and buidls for teh front stage speakers. Been worried about most of them having enough output for my room (>9000 cf). These look promising.  Requiring more depth than I'd hoped, but may be workable.

Did you get anywhere with this yet Rich?
Title: Re: Econowave Speakers
Post by: hometheaterdoc on February 18, 2012, 03:37:05 AM
last I heard all the wood was cut for the test mule cabinets and he was hoping to start gluing soon. 

I need to stop by this weekend and drop off some more flared ports and other tidbits for the build... and pick up my tube amps... 

I'm anxious to hear the design as well... after it's broken in for a few hundred hours :)  I think he's staying pretty true to the original Zilch design except for optimizing the box for the woofer a bit better on this first pass/attempt... crossover wise it will start as an exact copy of the Zilch design, just with much better parts than original spec :)

no idea if it will be midfi, or screechy and honky or what?  but sure am curious to find out.....
Title: Re: Econowave Speakers
Post by: Inscrutable on February 18, 2012, 04:44:44 AM
Cool.
Rich, you probably have what you need, but give a shout if you want/need clamps, pockethole jig, power tools, etc etc ... I have a garage full. Probably up in Cary for dinner with friends tonight and could drop them off.
Title: Re: Econowave Speakers
Post by: richidoo on February 18, 2012, 05:25:12 AM
Thanks for the offer Tim. I'm set for tools, at least for this project. Gluing up the boxes now. Using veneered ply with mitred joints and no external fasteners so gluing is slow with weights and clamps.
Title: Re: Econowave Speakers
Post by: rollo on February 18, 2012, 07:49:21 AM
  Looks interesting Richadoo. Have you selected the drivers yet ?


charles
Title: Re: Econowave Speakers
Post by: richidoo on February 18, 2012, 08:40:51 AM
Yes, it will use the woofers that I already own from my previous project, Eminence Deltalite II 2512.
(http://www.parts-express.com/images/item_large/290-593_l.jpg)
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-593

The HF driver is the ubiquitous B&C DE250, also used in Gedlee Abbey speakers which mgalusha and TomS use.
(http://www.parts-express.com/images/item_large/294-605_l.jpg)
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=294-605

in a QSC horn clone from parts express:
(http://www.parts-express.com/images/item_large/245-625_l.jpg)
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=245-625

The speaker is based on this design created by Zilch and Pete Schumaker on the Parts-Express Tech-Talk forum:
http://techtalk.parts-express.com/showpost.php?p=1637407&postcount=188

Shane bought upgraded parts for the crossover. Unlike the Zilch Delite which did not have a box optimized to the woofer, my box is designed to be a Butterworth 4th order max flat bass alignment with my woofers which supposedly will make -3dB @ 38Hz. But this woofer is not as efficient in bass as in midrange, so we'll have to wait and see how flat it is down to the port resonance. Baffle step will be corrected with a line level RC filter before the amp.
Title: Re: Econowave Speakers
Post by: richidoo on February 21, 2012, 05:49:03 PM
I got both box shells glued together... that is, the rear, top and 2sides, all mitred edges and no fasteners. The bottom panels still need to be cut to fit, and internal braces installed. Then the front baffle needs the driver holes cut before gluing to the box. Next 3 days are in the 70s here so I should make some progress.
Title: Re: Econowave Speakers
Post by: richidoo on February 25, 2012, 04:05:43 PM
Pics
(http://www.audionervosa.com/MGalleryItem.php?id=1216)

(http://www.audionervosa.com/MGalleryItem.php?id=1217)

(http://www.audionervosa.com/MGalleryItem.php?id=1218)

I braced up one of the cabinets today. It's a lot of work but it  really kills down the cabinet resonance. The box volume accommodates the added bracing.
Title: Re: Econowave Speakers
Post by: hometheaterdoc on February 25, 2012, 08:10:42 PM
Lookin' good, Rich!  getting much closer to the point of making some tunes :)  can't want to get a listen...
Title: Re: Econowave Speakers
Post by: Inscrutable on February 26, 2012, 03:26:22 AM
+1  :thumb:
Title: Re: Econowave Speakers
Post by: rollo on February 26, 2012, 07:54:18 AM
   Some serious bracing there . Mucho labor. Very nice.


charles
Title: Re: Econowave Speakers
Post by: rajacat on February 26, 2012, 11:34:17 AM
Ah :D....I see you're making excellent progress. I'm still waiting for the AE woofer group buy to come to fruition before I can start my waveguide project. It's been 3 months! :( [-o<
Title: Re: Econowave Speakers
Post by: richidoo on February 26, 2012, 12:47:11 PM
Thanks guys!  It is nice to be making dust again after a long winter.

Roy, I hope you get your TD12Ms soon. AE drivers are awesome. I'm gonna grab some of those molded plastic SEOS-12 when they are available, thanks for pointing me to the AVS thread.

Braces for the other box are all fitted, and gluing in now. They went a lot quicker on the 2nd one, for some reason... Making good progress while Daytona 500 is rain delayed...   :(
Title: Re: Econowave Speakers
Post by: rajacat on February 26, 2012, 04:18:56 PM
Rich,

I'll be doing the SEOS-18 with the TD-15M and active with the miniDSP :) I'm not sure which mic, db meter, etc. to use. I just might  make easy  on myself and go for with the Dayton OmniMic Precision Measurement System.

 I'll probably make my own cabinets. I've been thinking about a separate sealed box for the TD15M using 1-1/8" plywood and not using any interior braces. I'd cut a 45% angle out of the basic box for the proper toe-in angle and apply the baffle to that which would be constructed of a different material. It would be cool to add an outer layer of carbon fiber cloth to the baffle or maybe an exotic almost solid wood baffle.
   
 I don't know if anybody has tried this building method (the super thick plywood) but it might simply construction. Just throwing ideas out there.  I'm open to advice.

-Roy
Title: Re: Econowave Speakers
Post by: richidoo on February 26, 2012, 06:03:07 PM
I think that will be a sweet speaker system, Roy.

The Omnimic system is excellent, and a good value. 

Here are some articles I ran across yesterday on TNT-Audio.com, about cabinet wall thickness, and other design principles.
http://www.tnt-audio.com/clinica/speaker_design_pt1_energy_e.html
http://www.tnt-audio.com/clinica/cabinet_walls_e.html
http://www.tnt-audio.com/clinica/speaker_design_pt3_getstuffed_e.html

No matter the wall thickness you'll still want to have some internal bracing, especially with a sealed box using low frequency boost. But thicker is more self-damping so resonance is lower amplitude. Bracing forces resonance up into the more strongly damped frequencies of the thicker material. Without braces the lower midrange will still be colored. The trade off for thick baltic birch is you need at least a 1.5HP contractor saw and a fresh sharp carbide blade. And the speaker will be very heavy.  Start a new thread when you get ready to build. It will be fun to follow your project!
Title: Re: Econowave Speakers
Post by: rajacat on February 26, 2012, 09:28:49 PM
Rich,

Thanks for the links. I've got some reading to do. :shock:
It looks though I'll have plenty of time for that with the AE group buy delay.

I'll probably try Erich's BA compression driver so there'll  be some time before those appear too. With the BA cd I might be able to take advantage of the SEOS 18s' a lower crossover point.
Title: Re: Econowave Speakers
Post by: richidoo on March 06, 2012, 02:49:03 PM
The braces are finished. I had just enough GAF asphalt roofing membrane left from my previous project to use it on these too. Each piece is cut to fit inside each triangular brace area. In the last project I used 3M Super 77 spray adhesive to install the membrane, but it didn't hold well. This time I am using vinyl floor tiling adhesive. It paints on like tan cream, you let it dry clear, then the membrane sticks to it like pressure sensitive adhesive. Much stronger bond than the 77. I only tried a test piece last night, waiting for warm weather to do it outside because it smells.

So I built the crossovers today. Ready to install in the speakers. There is a rheostat L-Pad to adjust tweeter level, plus a fixed 3.3 ohm L-Pad. Other than that it is simple 2nd order Linkwitz Riley, with no impedance correction. This is a simple sloppy assembly to allow listening and tweaking it easier. The crossovers can sit outside the speaker with the driver wires going in through the ports. There is a separate crossover compartment in the bottom of the speaker for the final crossover.

Weather is looking good for the rest of the week.  :thumb:  I am trying to finish them up quick so Shane can at least hear the first rough draft before the 3 month baby sequester begins.

More pictures:
(http://www.audionervosa.com/MGalleryItem.php?id=1234)
All braces installed. I figured a better geometry for the second box I braced so they are slightly different. The better one is on the left, you can see that there are less interferences of two braces trying to be in the same corner, and easier to remember how to install them with all braces pointing in the same direction.   The bottom front brace is vertical instead of diagonal to accommodate the reflex ports which straddle the brace.

(http://www.audionervosa.com/MGalleryItem.php?id=1232)
A tall pile of 44 triangles of GAF rubberized asphalt roofing membrane for damping cabinet resonance between the braces. The braces raise the resonant frequency to make the damping more efficient.  Pieces of wood are the removable floor of the crossover compartment and bottom of the speaker. I accidentally chopped up one of the bottom pieces for braces, so some scraps are collected to make a new one. Fortunately it is on the bottom so appearance doesn't matter.

(http://www.audionervosa.com/MGalleryItem.php?id=1235)
Crossovers. Nice Erse magnetic core inductors for the bass, Jantzen Superior Z caps, Mills resistors, Dayton LPad. The little aircore coil is for the tweeter, a 20ga cheapie. We have a nice Erse 16ga coil to replace it, but it is lower DCR so we try this first, compare FR to the replacement coil later. Eventually the adjustable LPad (and fixed LPad) will be replaced with a single fixed LPad once we determine the correct value.

(http://www.audionervosa.com/MGalleryItem.php?id=1233)
The schematic of the crossover designed by Zilch and Pete Schumaker on PE's Tech-Talk forum. Their dialog suggests some other options we can try, like notches and impedance correction, if necessary.
Title: Re: Econowave Speakers
Post by: richidoo on March 06, 2012, 03:00:28 PM
The bitumen triangles are cut to fit the different size triangle spaces and numbered with chalk.

The upper front baffle relies on the cast aluminum woofer basket for bracing. I have found that the driver frames stop vibration pretty well in a narrow box.

The horn is thin plastic, so it might benefit from some resonance damping goo applied to the back surface. I found this cool latex rubberized asphalt driveway patch goo (http://www.latexite.com/pr-trpatch.html) at Home Depot that I'll try next time instead of the GAF membrane which is expensive, special order and too much labor. Hopefully it won't stink after it dries.

Note tweeter polarity is reversed. I don't like that, but that's the design we're starting with.
Title: Re: Econowave Speakers
Post by: BobM on March 07, 2012, 05:38:00 AM
Wow, it's good to be young. This is just too much work for me (unless I was retired, of course and had the time). wish I was closer so I could hear the results of these projects Rich.

Looking good.
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 07, 2012, 08:48:27 AM
Rich,

You are entirely too kind to try to get these done quickly so I can get a listen before the little fella gets here.  I really appreciate it... got the bags almost packed, the baby laundry is done and everything is setup... she's been in super hard core nesting mode now for more than a week....

Can't wait to get a listen... looking good.... loving that even the test mules are going to have cabinet dampening to eliminate those resonances as much as possible from the test listens :)

the sun is shining, Rich is gluing, all is right with the world :) hehehe
Title: Re: Econowave Speakers
Post by: tmazz on March 07, 2012, 09:01:25 AM
Wow, it's good to be young. This is just too much work for me (unless I was retired, of course and had the time). wish I was closer so I could hear the results of these projects Rich.

Looking good.


Road trip!  :thumb:
Title: Re: Econowave Speakers
Post by: richidoo on March 07, 2012, 10:38:01 AM
Road trip!  :thumb:

You're always welcome!   

The new adhesive doesn't work well. It is very tacky, both parts are glued, but then it peels off!  :wtf:

I'll try 3M # 90 spray next. $13/can.  :roll:
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 07, 2012, 11:09:03 AM
when all else fails, liquid nails or PL premium works wonders :)

the silicone that I just used on transformers would likely work as well... 
Title: Re: Econowave Speakers
Post by: richidoo on March 07, 2012, 03:20:18 PM
It has to be high tack instant grab so any kind of wet glue won't work, no way to clamp it in place.

I bought more 3M Super 77, some 90 and some true contact cement. I read the directions for 77 again and there is advice for extra strong bond: coat both surfaces, let it dry for a minute, then join. I tried it and it worked much better but still wants to peel away slightly. It also used a lot of spray for just one piece so it's too expensive.  High Strength 90 requires spraying both sides, and it costs $13 can, so that's out too.

So I'll try the Weldwood gel contact cement tomorrow. Previous attempts with Weldwood greenieweenie water based low odor "contact cement" failed, but this stuff is the original dope sniffer's special with toluene and MEK.  :yay2:
Title: Re: Econowave Speakers
Post by: jianghai on March 07, 2012, 08:44:50 PM
I don't know anything about real DIY stuff but how about those quick setting 2 part epoxies? They seem very strong and set very quickly.
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 08, 2012, 06:53:58 AM
I'm on the pre-order list for entirely too many of those new plastic SEOS units... 

I have a feeling Tim and other locals are going to get to benefit from "research" as I've got more waveguides coming than I'm ever going to be able to use myself even if I start giving them away to friends :)

Title: Re: Econowave Speakers
Post by: richidoo on March 08, 2012, 10:17:14 AM
The contact cement is working well, one done, one to go. But it really stinks, even outside. I'm taking a break to sober up.  Should finish the cabinet damping today, then the rest can be done indoors.
Title: Re: Econowave Speakers
Post by: mgalusha on March 08, 2012, 12:52:53 PM
That stuff is evil, I bought a chemical respirator for working with things like contact cement, acetone, keytone and other nasties.

I'm looking forward to your thoughts. I suspect the CD could really use some impedance compensation. I know you have read Wayne Parham's crossover 101 stuff and he is pretty adamant about the need for zobel's and other comp networks.
Title: Re: Econowave Speakers
Post by: BobM on March 08, 2012, 01:26:39 PM
Rich ... Rich ... wake up!!!

Someone call the paramedics.
Title: Re: Econowave Speakers
Post by: richidoo on March 08, 2012, 01:28:08 PM
Hi Mike,   Yes, I used a respirator for the second speaker, didn't smell a thing, and didn't get stoned.  MEK is not good for you. Thankfully, the damn roofing membrane is all used up and may never return. Such a pain to work with, but it does take down the wood ring a lot though...  They make a self-adhesive version, but I bet it doesn't stick good enough for vertical applications of small pieces.

In the Tech Talk discussion that created this crossover, there was talk of notches and impedance correction, but Zilch didn't choose those for the final XO. The rising CD impedance's effect will vary with the damping ability of the amps, so it might benefit the HF to leave it untamed for the SS amp, and add it for the tube amps. Flattening woofer impedance will change the crossover parts values, but might sound better by making less woofer in the upper mids.  It's all out there to try.

Are you still planning to build 4pi Mike?
Title: Re: Econowave Speakers
Post by: richidoo on March 08, 2012, 01:31:09 PM
Rich ... Rich ... wake up!!!

Someone call the paramedics.

 :D
Title: Re: Econowave Speakers
Post by: richidoo on March 08, 2012, 03:06:09 PM
(http://www.audionervosa.com/MGalleryItem.php?id=1236)

Proof I can count to 22.

Next up is adding FG insulation as acoustic damping to stop the echoes.
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 08, 2012, 05:32:24 PM
in my best Count from Sesame Street voice "1.. bwah... ha ... ha ... ha"  :)

Looking good, Rich!  Looks like a little gluing on the front panel and some parts attachment and they're almost ready to make some noise!

Title: Re: Econowave Speakers
Post by: richidoo on March 08, 2012, 05:48:30 PM
Yup, getting close now! At least to the first draft.
Title: Re: Econowave Speakers
Post by: mgalusha on March 08, 2012, 07:50:11 PM
Are you still planning to build 4pi Mike?

Good to hear you went with the respirator, we don't want you to drop.  :shock:

Yes, at some point I will build a pair just so I can hear them. I have 4 of the JBL 2226H woofers, so I need the wave guides and B&C drivers. First I will likely build a pair using one of the 2226H and a Beyma TPL-150, sort of e-wave/four pi like but with more top end extension. I know there will be a lot of work to get the crossover correct but I'll keep them outboard and build/measure/listen until I get them right.

This project is certainly moving along nicely, I am enjoying the build from here.  :thumb:
Title: Re: Econowave Speakers
Post by: richidoo on March 09, 2012, 08:34:08 AM
Pics:
(http://www.audionervosa.com/MGalleryItem.php?id=1240)

(http://www.audionervosa.com/MGalleryItem.php?id=1238)

(http://www.audionervosa.com/MGalleryItem.php?id=1239)

(http://www.audionervosa.com/MGalleryItem.php?id=1237)
Mess... 

The horn is plenty strong enough to support the DE250 CD without a rear brace. The other CD we have is the Radian 475PB. It is larger and heavier (PB = plubum?) but I think it will not need a brace for normal use.

Remaining: build the ports and glue baffle to box.
Title: Re: Econowave Speakers
Post by: mgalusha on March 09, 2012, 08:54:25 AM
Looking good Rich!
Title: Re: Econowave Speakers
Post by: richidoo on March 09, 2012, 11:48:43 AM
Thanks Mike

Ports built. 3.25 inches long extensions made from 4" PVC pipe, added to Parts Express 4" diameter flared port makes a 6.89" effective port length. I machined them on the table saw using the crosscut sled and twisting them through the blade by hand - fun! Taped them to the Parts Express flared ports on the inside of the tube with 2" aluminum metal HVAC duct tape. Turns out, two of the PE flared ports taped together back to back would be almost perfect length, with flares at both ends, and cheaper.

Now to try to find some 5 min epoxy to glue them to baffle.
Title: Re: Econowave Speakers
Post by: richidoo on March 09, 2012, 01:50:03 PM
I painted the inside of the ports black because the white PVC pipe and shiny aluminum tape were visible from the front of the ports. The ports are epoxied in. I will seal the back of the port mounting with caulk, then I'm ready to glue the front baffles to the box.  I think it will take a little massaging with the sanding stick to get it to fit perfectly, then clamp it into submission.  :twisted:
Hopefully, the miters will line up close enough to be within range of a 1/8" roundover bit.

A buyer review on the PE website of the i152 horn complained that the DE250's threaded studs are too short for the thick mounting tabs of this horn. To fix this easily without cutting bolts, I bought four M6x1.0 x 40mm metric bolts from Home Depot, $0.60 iirc. Screw one of the nuts that come with the DE250 all with way to the head of the bolt, then slide on a lock washer and a flat washer. Screw the bolt through the horn tab into the CD, bottoming the bolt in the CD bolt hole. Then with a 10mm open wrench, tighten the loose nut that's on the bolt down toward the horn tab to gently squeeze the lock washer almost flat.
Title: Re: Econowave Speakers
Post by: richidoo on March 10, 2012, 02:48:46 PM
The first box is glued. They should be playing tonight, with a little luck...   [-o<

The front baffles lined up perfectly, no sanding or cutting needed. I love when it all comes together.
Title: Re: Econowave Speakers
Post by: jianghai on March 10, 2012, 05:05:05 PM
Looks amazing! Soo jealous of your DIY chops. Can't wait to hear em.
Title: Re: Econowave Speakers
Post by: richidoo on March 10, 2012, 06:01:32 PM
Thanks Jianghai! We will get together again soon. I look forward to that!! I think Carl might do his DAC-off before mine. But I can sneak in a preview... ;)

I have one playing now while the other dries. First impressions are that the CD/horn is very clear and low distortion, easy to listen and very dynamic. The bass ports work well, loud and tuneful. Needs speaker positioning to get rid of the lumps.  Midrange is OK so far, I don't really notice anything crazy, except for a "buzzy" presence range 3-4k?

Need lots of break-in, measurement and EQ fixes before any judgement. After 15 minutes it is getting noticeably better already. It always amazes me how much speakers change in the first 20 hours. These woofers are already fully broken in, but the XO, wires and CD are new.

The rheostat L-Pad allows adjusting the volume of the CD in relation to the woofer. It goes all the way down to "off," where it was when I first listened and thought I screwed up the wiring until I remembered to turn up (on) the tweeter.

The buzz seems to be gone now.  :D

Time to go unclamp the other one, see if we can get some stereo action tonight!
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 10, 2012, 06:11:38 PM
Woohoo!!  Tunes!!  It lives!!

Can't wait to hear them... I was wondering if it was going to make it this weekend...  I checked in earlier today and hadn't seen anything posted... I figured you were too busy listening :)  turns out you were waiting for glue to dry :)
Title: Re: Econowave Speakers
Post by: richidoo on March 10, 2012, 07:39:07 PM
Finito! at least for now. I still need to finish the wood, and tweak the sound, but they are playing, in stereo, and it very sounds good. A nice improvement, methinks.

Pics:

(http://www.audionervosa.com/MGalleryItem.php?id=1251)
Caulking the rear of the ports to seal them tight.  Didn't want glue or caulk to show under the edges in front.  The inside diameter of the port and extension pipe are equal.

(http://www.audionervosa.com/MGalleryItem.php?id=1253)
Monkey ready for liftoff

(http://www.audionervosa.com/MGalleryItem.php?id=1255)

(http://www.audionervosa.com/MGalleryItem.php?id=1254)

(http://www.audionervosa.com/MGalleryItem.php?id=1252)
Gluing on the front baffle

(http://www.audionervosa.com/MGalleryItem.php?id=1250)

(http://www.audionervosa.com/MGalleryItem.php?id=1249)
New ride. Smaller and faster.

Thanks to Zilch and Pete Schumaker for this great design. Thanks to Shane for making this project happen months sooner than I intended. Thanks to my wife and kids for helping. And thanks to AN gang for encouragement.
Rich
Title: Re: Econowave Speakers
Post by: mgalusha on March 10, 2012, 07:54:45 PM
Very nice. The monkey is going for a heck of a ride. :)
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 10, 2012, 09:08:54 PM
Awesome, Rich!  They look really great!  It's amazing how much smaller and less dominating they look than your current speakers..... yet they're not exactly small speakers themselves :)  It looks positively spacious in your listening room right now based on the photos :)

It's great that they're giving a positive first impression with no break in.... sounds like they need some tweaking, but you're happy with the initial sound....that bodes well :)  I'm very happy you are enjoying them so far and I'm glad to have been able to help a little bit in getting them this far.... you've done all the hard work.. I just spent a few minutes ordering parts :) hehehe....

can't wait to hear them....
Title: Re: Econowave Speakers
Post by: stereofool on March 11, 2012, 04:53:01 AM
Looking VERY good, Rich  :thumb:!

I need some of your project 'finishing' genes  :lol:.
Title: Re: Econowave Speakers
Post by: mdconnelly on March 11, 2012, 05:03:31 AM
Rich, you are Da MAN!   Can't wait to hear those babies.  What I'd give for your skills, attention to detail, patience and, well, time to tackle such projects!   
Title: Re: Econowave Speakers
Post by: TomS on March 11, 2012, 05:59:19 AM
Great work Rich, you are a machine of DIY productivity!

So do you have an old speaker graveyard out back somewhere?
Title: Re: Econowave Speakers
Post by: lonewolfny42 on March 11, 2012, 06:15:12 AM


                   (http://shoottssc.com/images/Great_Job_clip_art_1_.gif)
Title: Re: Econowave Speakers
Post by: richidoo on March 11, 2012, 06:31:44 AM
Thanks guys!

The old ones get sold if they are any good, or more often go to the dump.

Stayed up too late listening to these last night. Hard to shut them off, that's a good sign. The tweeter level knob on the back allowed me to dial them in pretty close. Once I pick a level I like then I'll replace the dial with fixed resistors.
Title: Re: Econowave Speakers
Post by: lonewolfny42 on March 11, 2012, 07:51:48 AM
Spike those speakers Rich.... :thumb:

(http://www.oregondv.com/1.50_Gold_Speaker_Spikes.jpg)
Title: Re: Econowave Speakers
Post by: BobM on March 11, 2012, 08:11:37 AM
I love it when a plan comes together!

(http://3.bp.blogspot.com/-Mve8RtGexsM/TajrSPhIXmI/AAAAAAAABIk/Z5D-VGORXKM/s1600/Hannibal_a-team.jpg)
Title: Re: Econowave Speakers
Post by: richidoo on March 11, 2012, 11:38:24 AM
Spike those speakers Rich.... :thumb:

Will do Chris... thanks.  Bass could be a little tighter. Shane do you have any of those PE spikes left?

All the buzzyness is gone now. There is lots of detail, I'm not used to that. I keep turning down the horn level and it gets better and better. The L-Pad is a great idea. I am already  way less than halfway down, but getting close now.

The horn and woofer are integrating much better now. Beautiful tone, even on classical stuff. Can't believe how low distortion is on the horn. The only thing that still sounds a little off is the reflex bass, probably the port phase. But the box is designed to be perfect for sealed also, which I haven't tried yet.

Imaging is good, there might be more on the table. I need to make them wider and toed in even more. They are crossing about 5 feet in front of me now, with ~55degree listening angle.

Last night I listened to compressed FM radio, then this morning Jeremy Pelt radio on Pandora, it all sounded good, but I was hesitant to throw something really hard at it. I didn't want to hear the warts that mean I need to start looking for something next. I let it blast for a few hours this morning while we were out, then I put on Minnesota/Vanska Beethoven 7th, way up loud. Awesome!  The power and low distortion is definitely there. The horn has no problem at all playing perfect tone at high volume. The woofer keeps up fine in the midrange. The bass is loud enough, but is a bit too poofy and some EQ lumps, but that could be room. The box has some vibration, so I will add some crossbraces.

The limited vertical dispersion of the horn (60 degrees) seems to have helped the "shouting" that I have always had in this room. Flutes and piano don't bite back as much. I think that the SEOS horn has even lower vertical angle of only 45 degrees?

My wife and kids like the sound of it. I told her that this is just an experiment to lead up to a bigger one. She how 'bout an experiment leading up to a smaller one?
Title: Re: Econowave Speakers
Post by: jianghai on March 11, 2012, 11:56:47 AM
The old ones get sold if they are any good, or more often go to the dump.

Don't dump em! I for one would love to see em go around for people to listent to.

Spike those speakers Rich.... :thumb:

Spiking speakers is a great idea. What I've done is to spike up a pair of marble cutting boards and using foam pads between them and speakers. That way the "spikes" can be swapped between whatever speakers you want.
Title: Re: Econowave Speakers
Post by: richidoo on March 11, 2012, 12:38:28 PM
I built these with the idea that our locals can take them home to try and see if they like the sound. They are a popular design so they will be easy to sell when I make bigger ones with two (4?) sealed woofers.  :twisted:

My previous speakers are huge and very heavy so I will have to either sell them to a pickup buyer, or the boxes might hit the dump and ship off the electronics to someone on diyaudio. The nice thing about them is the lower resolution makes for very deep immersion in the music. These horns are a bit too much detail for me. I focus on reverb trails and cracked notes, stereo pan instead of the melody. But the detail is great on classical symphonies, quartets and chorals, etc, where the tone is so exquisite. Maybe I'll start listening to less Pandora and more CDs again...

I think I can also add more stuffing to the cabinet to tighten the bass more. That plus spikes and some cross panel bracing will be nice. More break-in and fixed pad will help the highs further too.
Title: Re: Econowave Speakers
Post by: stereofool on March 11, 2012, 06:41:45 PM
Rich,

What about the possibility of smaller cabinets to house the horns and midrange, and then build big-ass...pant flapping subs ...which you could kind of 'hide' in the corners.

Maybe Julie would go for that  :?.
Title: Re: Econowave Speakers
Post by: tmazz on March 11, 2012, 08:50:52 PM
Quote from: richidoo link=topic=3697.msg50340#msg50340
These horns are a bit too much detail for me. I focus on reverb trails and cracked notes, stereo pan instead of the melody. 

Give it some time. Right now all that detail is new to you and you are "discovering" all of the sounds within the music that had evaded you before. Once you get a bit more used to that level of detail it won't be that distracting and your attention will go back to the melody.  8)
Title: Re: Econowave Speakers
Post by: Inscrutable on March 13, 2012, 04:01:50 AM
Great job Rich .. Looking and sounding mighty impressive ... can't wait to hear.

Obviously, haven't seen a build like this one ... do you have a guess on the system sensitivity?  Would guess well north of 95. Perhaps north of 100?

Re Steve and Julie's comments .. weren't the original Econowaves in fact in much smaller enclosures? (shorter at least)

I have all the parts in my cart for LCR front stage.  Haven't been able to model with my IB15's instead of the Eminence ... WinISD blows up on me ... get soem kind of 'dividing by zero' error message some kind of pilot error I am sure, or some kind of issue from manually entering the driver parameters .. wish these were in the canned database...
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 13, 2012, 04:28:35 AM
Tim,

Don't go ordering parts just yet :)  I've got some SEOS waveguides coming to play with and compare with these QSC ones, as well as some different drivers... this econowave may be the value to beat.... but we should hear the options before spending more money :) (or at least before *you* spend any money... it seems I'm bound and determined to spend more :) hehehe  also, let me order the stuff for you if you're ok with that... I get better prices with my wholesale accounts)

Rich was awesome to build out the test mule cabinets for this and put everything together... He's the man, here because I certainly don't have the time right now to be cutting up wood.....  but this design was meant to be an experiment just so we could all hear it and see if the concept was sound or not...  

it's certainly looking like it's worth pursuing based on comments here and an email or two Rich and I have swapped (I need to get over to his place soon to get a listen to it in person)...  but it sounds like there is still some tweaking to do on crossover, maybe even compare to a couple other drivers to see if its ideal or not...  plus, as I said, I've got way too many of the SEOS-12 plastic waveguides on pre-order to come in and see how that affects things compared to this QSC waveguide....  I'm hoping its better and if you decide to build some speakers that you'll take a few of them off my hands :)  Otherwise, its just that many more I'm going to have to figure out how what to do with them other than store them in a bin in my garage for a while :)

More info in the big AVS Forum thread on the SEOS, including a couple new designs just posted with an economy Dayton driver that's about to be introduced at parts express:  http://www.avsforum.com/avs-vb/showthread.php?t=1291022 it's pushing up to 110 pages now... last ten pages or so are likely most relevant at this point...

I've got 3 AE TD12X woofers hopefully shipping to me this week if John will read his email and put shipping labels on the boxes sitting at his place.  I've also got a couple different folks that are willing to sell me pairs of TD15M woofers from the group buy whenever that actually is able to ship out.... so it should be interesting to hear those drivers in comparison to the eminence woofers.  but as usual, I'm getting ahead of myself :)

Can't wait to get over your way and have a listen, Rich... hopefully sometime this week or maybe this upcoming weekend...  it all depends on someone else, though right now :)
Title: Re: Econowave Speakers
Post by: richidoo on March 13, 2012, 12:14:35 PM
The new server is fast, and no login error!   :yay2:


Tim, sensitivity for this 'Ewave Delite' is nominally 90dB. The driver is relatively high EBP compared to subwoofer drivers so the woofers 99dB rating does not extend into the bass freqs. The horn is severely padded to mate with the woofers low frequency response. When I build my own speakers they will be WTW so that the paralleled woofers will allow 6dB less pad on the horn.

The published Econowave Delite design that I am using here was prototyped in a Parts Express knock down cabinet. It is cheap, available and easy to assemble for those who can't build or design their own box. Zilch said many times that his design did not include the bass alignment, you were on your own for that. He used the same box without mods for all the 12" "deluxe" designs no matter which woofer, so they were all compromised in the bass to some degree. The knock down cabinet is a compromise for this woofer because it is too small to achieve max flat response. I used WinISD to calculate the max flat Butterworth alignment to get the lowest flattest response without regard to size or cost. It is pretty big for a single 12" driver when you consider the Geddes Abbey speaker which requires subwoofers. Mine don't require subwoofer to enjoy all kinds of music at high volume. You can reduce the volume of the box and the simulator will change the port dimensions to maintain flat response, but sensitivity and bass extension will decrease.

You can use Unibox
http://audio.claub.net/software/kougaard/ubmodel.html
or Jeff Bagby Woofer Box
http://audio.claub.net/software/jbabgy/jbagby.html
simulators are more powerful and flexible software. But WinISD is adequate for this job.  Maybe it can't handle IB type drivers? Please post the IB15 T/S specs? Thanks
Title: Re: Econowave Speakers
Post by: richidoo on March 13, 2012, 02:01:31 PM
Come hear it if you want Shane, but there is a lot more work to do before it is worthy of golden ears. Set your expectations accordingly. ;)
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 13, 2012, 02:27:24 PM
Come hear it if you want Shane, but there is a lot more work to do before it is worthy of golden ears. Set your expectations accordingly. ;)

duly noted.... :)
Title: Re: Econowave Speakers
Post by: Inscrutable on March 14, 2012, 02:01:58 AM
Shane,
OK, thanks ... I will direct my energy at getting the boat in the water rather than the screenwall. Have some rewiring to do and recovered bolsters to mount and insturment panel to refinish and ... like they say ...
Bring
Over
Another
Thousand

Sounds good on the waveguides and drivers. Checked the Dayton site ... the Designer 12's are up, at <$80 each,  pretty low Fs compared the Eminence 12's (which I don't really need since mated with HT sub), not very sensitive ... we'll see ...  Now, if there were a good low-cost altenative to the DE250 ...

If not confidential, what kind of price did they get on the AE drivers?  I REALLY wish he was still making the IB15's ... would save me a lot of mental grief deciding whihc way to go now for LCR and/vs sub. Ah well ...

Yeah, I can deal with lightening your load on teh waveguides ...  the AE 12TDX are probably overkill for the screenwall, tho probably would be sweet for a 2-ch pair.
Title: Re: Econowave Speakers
Post by: Inscrutable on March 14, 2012, 02:16:04 AM
Rich,
Yeah, while I would definitely go with larger boxes as you have for a freestanding pair, smaller cabs will work fine for me as I don't care if I don't get much below about 60Hz. I would however like to model a shallower box so I don't have to bring the screen out as far - something on the order of 8-10" rather than 14-16".

WinISD drove me nuts. I tried inputting a couple different ways - found guidance on which parameters to input (only), and other tips on what order to input them ... gets me past the conflicting parameter entry messages, but still get errors when running a project. Maybe sometime if we are together you can show me the error of my ways.

For morbid curiosity, these are the TS parameters for the drivers:
IB15 8ohm
 Fs: 16Hz
 Qms: 6.8
 Vas: 439L
 Cms: .45mm/N
 Mms: 220g
 Rms: 3.239kg/s
 Xmax: 18.5mm
 Xmech: 25mm
 Sd: 830sqcm
 Vd: 3.07L (p-p)
 Qes: .78
 Re: 5.5ohm
 Le: .33mH
 Bl: 12.49Tm
 Pe: 500W
 Qts: .7
 1WSPL: 86dB
 2.83V: 87.3dB
 
And yeah, not really designed for IB modeling, but actually was trying to model for more conventional sealed/vented enclosure to see if I could go that way with these or not. Also looking for the power necessary to achieve full output, as I will have to be making a decision on an amp soon.

Let us know when the babies are ready to receive visitors :clap:
Title: Re: Econowave Speakers
Post by: richidoo on March 14, 2012, 08:35:07 AM
Tim, thanks for typing all that out. I got it working in WinISD Beta. I entered everything as you listed, except for Sd and Diameter I converted to meters first.  It's like college chemistry has returned to haunt you - watch the units! ;)

Running a box simulation it shows that these drivers will require gigantic boxes. Optimum closed box size is 21000 liters (the size of an attic?) Vented is something like 2500 liters. A box of 400 liters would make a 3dB bump at 30Hz, it would drive you nuts. The Qts is very high, .7 so they will sound warm and not very detailed if asked to play into upper midrange frequencies to match up to a horn. So forget these for Econowave type speakers.

Maybe if you make a faux wall 2-3 feet in front of your current front wall, to install these as IB subs, then flush mount the screen and put the speakers behind the screen or flush mounted in the wall.
Title: Re: Econowave Speakers
Post by: Inscrutable on March 14, 2012, 09:09:22 AM
Thanks Rich so much for the effort. Sounds like that fixes my decision ... move on as originally planned to use these in an IB configuration for subs, and deal with the LCR completely separately with new drivers. Now the problem is that the size of my "indoor" enclosure was only going to be about 60 cf (about 1700 liters) ... more of  asealed box than an IB. So I eiether need to accept that limitation, or go back to venting these to the attic and dreaming up some kind of removable insulation panel.

As an IB, the Qtc ~= Qts, and also I'll be EQ'ing it to boot, so should be fine from an articulation standpoint. I am only worried if I have enough drivers for necessary output in so large a room. had planned to try it and buy 4 more if needed, but my hibernation has put a crimp in that unless I can pry some away from current owners. Guess if they don't put out enough I could sell them and get all new drivers for the sub. I'll bet I could sell them for at least what I paid.

Since you already have them plugged in can you tell of what kind of output they are capable if we assume about a 1700 liter sealed box and 4 drivers? I guess what you've already run showing the 21000 liter box approximates venting into my attic - could even increase that number. Do you recall what that showed?

If I'm being too big a PITA don't hesitate to say so.
Title: Re: Econowave Speakers
Post by: richidoo on March 14, 2012, 09:51:05 AM
4 drivers in a sealed box of 87363 makes Qtc .71.
4 drivers in a sealed box of 1700 liters makes Qtc 1.0, that's 60 cu. ft, ~6' x 4' x 2'. 

See tim.jpg below for FR at 2.83V, 4 drivers in one 1700liter box. At 500W it is same curve at 120dB up from 93dB at one watt.

With all the drivers in one box acoustic modes will be worse than if you spread the sources around the room.
Title: Re: Econowave Speakers
Post by: Face on March 14, 2012, 04:37:01 PM
FYI, this program is far superior to WinISD: http://audio.claub.net/software/jbabgy/WBCD.html

The only negative(if you want to call it that), you need 32bit Excel installed on your machine.  
Title: Re: Econowave Speakers
Post by: richidoo on March 18, 2012, 05:52:28 PM
Getting back into this now after a week of real life.

I listened and experimented a bit this afternoon. Toed the speakers in even more, and sat up closer to widen the triangle.

Some songs benefit from cranking in more horn, while other songs need less. The double edge sword of high resolution. Turning down the level of the horn does not reduce resolution.  So it is not ideal for pop music, but well recorded music sounds great, even high resolution audiophile stuff and rock recordings with sonics in mind. The tweeter is broken in more now, but there is still an edginess that distracts. I'll try the Radian tweeter this week too.

Bass and midrange (the woofer) is not as clear as it should be. It's not keeping up with the horn.  I think it's mostly box vibration, so I will be adding cross bracing tomorrow.

It could also be the driver, with paper cone, but the cone feels very stiff and thick, and the driver Q is only .38 so it should be fine thru the 1400Hz xo.

Maybe the iron core coil on the woofer should be air core for lower hysteresis and distortion? It is Erse Super Q type, supposedly lower hysteresis, but it is still a magnetic core.

Speaking of awesome air core inductors, Did you guys know that North Creek Audio's shop burned down in January? He says they are rebuilding and will be selling coils again in spring/summer.

I am remembering hearing Jason's Abbeys which have much clearer midrange. They use extremely solid self-damping urethane box and a B&C woofer, which easily keeps up with this tweeter.
Title: Re: Econowave Speakers
Post by: richidoo on March 18, 2012, 05:59:38 PM
I forgot to mention that I (edit: temporarily) blocked off the reflex ports to make Qtc .57. Clearer without the port phase shift, but not as low. The midrange coloring remained.
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 20, 2012, 09:42:12 AM
is the edginess a specific frequency?  maybe a response anomaly that needs to be filtered out? 

Is it because it's missing the BBC dip or equivalent in the midrange?

Is it all over and might be addressed with different caps to flavor? I've got some oil caps that could be tried...

wanna try the better air core on it and see what that does?

I honestly didn't read much of the details about this design.. I thought the stock crossover was lower than 1400?  Hmmm... maybe I should go read some more :)

I'm still hoping to get over to have a listen at some point soon... running out of time, though... after the last few night, she is *more* than ready to get the show on the road and for him to arrive... doc said in appt. last week that she's unlikely to make it to her due date as things are already starting to progress...

Title: Re: Econowave Speakers
Post by: richidoo on March 20, 2012, 01:10:53 PM
Hi Shane!!  :D  Great news about the baby. Won't be long now.

I would say edginess  is at 4-5k if I had to guess. The presence/sibilant region, maybe a little lower. It has improved a lot since new, but still some there. I'm at ~50 hours now, but not a lot of very loud playing. Imagine a trumpet that sounds like a kazoo. That's what it was when brand new, now only 1% of the kazoo remains, only audible to me on instruments that have rich harmonics and edgy tendency. I don't think it is all over everything. Interestingly, piano, one of the hardest instruments to get right in tone, attack and scale sounds excellent.  But it doesn't have the edgy bite of a violin or trumpet which excites this thing. Overall the highs are very nice, non fatiguing and accurate even at very loud levels. The midrange part of horn is nice. Impedance bump in that upper midrange could be affecting the crossover filter.

I don't know the FR. I will measure and post it. It'll be interesting to see how it jibes with Zilch's prototype.

The Jantzen caps are smooth and relatively personality free, so I don't think they are a cause, and I am leery of painting over problems yet with soft parts. But a notch or impedance correction might be needed.

I am not sure of the design crossover frequency. I read 1400 for something, but it might have been a different speaker. Come to think of it 1100 also sounds familiar. It all blends together after a while.

Carl was over today and helped place the speakers. Further apart, and aimed straight on. Better overall balance, but imaging is not quite as strong center image, but still good.

We discussed the half dozen or so issues that prevent these speakers from being full audiophile grade.

I need to do some mods and experiments to find the causes before buying new parts. Active crossover, bracing, FR measurement.  Time to start whipping this mule. The last week has been very busy. 
Title: Re: Econowave Speakers
Post by: Carlman on March 20, 2012, 06:03:58 PM
I was surprised at how much these speakers changed by moving them around a bit.  We did very coarse adjustments today, 1 foot movements, toe angle changes over 20*, etc...

By the end they were producing a very satisfying sound, good PRAT too.. They have the 'wholeness' of 2nd order crossovers, very nice to experience.

I'll be interested in what Rich does next.  These are nice speakers to experiment with.. find out what works/doesn't work for your tastes, and change... a tweaker's delight. :)

-C
Title: Re: Econowave Speakers
Post by: richidoo on March 21, 2012, 10:12:36 AM
Opened up the speakers today, to prepare for adding crossbracing. Probably about 10 pieces adding to each speaker, connecting the opposite sides. It would have been much easier to do before the baffle was glued on, but it's not too bad. The woofers are screwed to the front baffles from behind. It was easy to remove them, I hope they are as easy to reinstall.

I'll also add more FG stuffing to tighten the bass a bit, after I read up on the loudspeaker cookbook about how much is recommended. What I have in there now is a 1.5" thick pink FG coating of the interior, there is not much density to it. I'll pick up a roll of R13 (4" thick) and put that on 3 surfaces, 1 side, bottom and rear, but not a complete coating.

I played a woofer direct connected to amp with no box, aimed at the listening position. It sounds clear enough considering no tweeter. It's breakup peak is obvious and does not sound like the edginess mentioned previously. I don't think there is a problem with the woofers themselves.
Title: Re: Econowave Speakers
Post by: BobM on March 21, 2012, 10:37:23 AM
I know it's an expensive option Rich, but have you considered adding some judicious amounts of Black Hole 5? You only really need it behind the drivers, and then the need for additional stuffing becomes mute. You really don;t need stuffing if you use Black Hole 5 correctly. It also somehow adds the appearance of having a larger enclosure for the drivers.
Title: Re: Econowave Speakers
Post by: richidoo on March 21, 2012, 02:24:26 PM
I have never tried it Bob, but I think it's time to try it. Danny Richie sells a product that is similar, and Parts Express sells something like that which only absorbs with no box vibe killing power.  I try to do things  on ultra budget, but I can only get so far that way. 

It was more difficult to get the woofer re-installed after the braces were added, but not too bad. One done, one to go. I added another layer of 1.5" loose FG around the middle section of the box around the woofer, according to Vance Dickason's advice. Could probably use more, but it's pretty easy to add more.
Title: Re: Econowave Speakers
Post by: richidoo on March 21, 2012, 06:15:05 PM
OK now we're getting somewhere. The box vibration was much of the problem in the midrange. It's not accuton mids, but the midrange tone is not distracting anymore.

I added 4 braces per box. 1 side to side in the bottom section below the ports, one front to back in the bottom below the ports, one front to back below the woofer. Then one side to side between the woofer and horn. There's not really any other opportunity to add more permanent cross braces. I need some front to back cross bracing between the woofer and horn as I can still feel significant vibration there where only a thin strip of wood between the driver holes is resisting the woofer motion and pressure. If I glued braces in there it would jail in the woofer. So I have to devise something removable, without screws showing on the outside. Maybe some brackets or something, or just wedge them in somehow to flex the front baffle outward and hold it out in tension so it can't vibrate in and out.

I fine tuned the speaker positions and toe angles with tape measure and adjusted the horn levels for center image using mono recording. The couch was 3 inches off center. With horns crossing about 2 feet in front of me the imaging is excellent. Big thanks to Carl for once again setting my speaker positioning ship on the right course.

The crossover is traditional LR2, which requires the crossed drivers to be out of phase, but it doesn't matter which is reversed. The published design has the horn reversed. I think tweeters should be correct polarity. Imo, ideally LR2 should be a three way so the midrange is out of phase and bass and tweeter can be right. Reversing polarity at the speaker posts changes both drivers, and the speaker sounds more natural to me overall. But the bass is a little weird occasionally. It sucks air when it should blow on kick drum and bass plucks, but it is a lot less distracting than weird treble.

The bass ports are too loud. With Sonos Bass EQ I can pull out 5dB and it sounds about right. Turning up the horn knob just makes the mids recede.  I think I can add more internal damping to reduce the efficiency of the bass. If I put it down in the bottom near the ports and away from the woofer hopefully it will damp the ports more than the cone itself. The ports are contributing power up into the 200-300 area, so chilling them out will improve lower midrange clarity too.

So after all these changes it sounds a whole lot better. Definitely into the audiophile territory now. More tweaks tomorrow.

I played Colbie Caillat for my daughter tonight, she gave them the thumbs up. I don't think she ever heard her music played on high end speakers, since none of my previous projects were.  :rofl:  Now my wife is sitting next to me reading a book tapping her fingers and nodding her head to the music without complaining about turning it down or change the song. The CD/horn is very easy to take.
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 21, 2012, 09:03:48 PM
woohoo!!  that sounds very encouraging, Rich!  Now I definitely can't wait to hear them :)
Title: Re: Econowave Speakers
Post by: BobM on March 22, 2012, 05:46:31 AM
How about hooking something up that braces the back of the woofer against the back of the cabinet, effectively supporting the woofer from the rear? Not sure how you would attach it to the woofer magnet structure itself, but I've seen that done elsewhere.
Title: Re: Econowave Speakers
Post by: richidoo on March 22, 2012, 06:25:40 AM
My feastrex had a bolt hole in the rear so I made custom threaded rods to mount and tighten it.

(http://www.eminence.com/img/speakers/large/DeltaliteII_2512--1.jpg)Eminence Deltalite II 2512

This one has a vent and fins and everything else is rounded on the rear of the motor, so the rear of the woofer is pretty much useless for bracing.

I think I will make a brace to go from the brace on the back of the box at the height between woofer and horn and then come up front up to the top mounting screw of the woofer and attach it with brackets so it's removable. I really want to brace that sliver of baffle between horn and woofer. The other side of the baffle is braced, and I think that one made the biggest improvement.

The woofer can be taken out of the box through the horn hole, so a permanent brace would block its exit.
Title: Re: Econowave Speakers
Post by: Inscrutable on March 23, 2012, 02:59:51 AM
woohoo!!  that sounds very encouraging, Rich!  Now I definitely can't wait to hear them :)


+1  :thumb:
Title: Re: Econowave Speakers
Post by: richidoo on March 23, 2012, 05:26:20 AM
I'm pretty sure that the ports are too long, because bass is too low, too loud and too slow. I realized that I used the published T/S specs instead of the actual driver measurements in the simulation.  Adding more stuffing reduces the midrange sensitivity and doesn't change the port SPL. Sealing the ports helps, but the box still speaks a little.

WinISD does not allow adjusting port length. Port length is the result of all the other adjustable variables.

I did finally put on a symphony, Beethoven 6th, last night. It was OK, but I had to stuff the ports. The good news is that the CD and horn play fine on the loud classical music. And no flute stabs from ceiling reflections. That's with 60 degree vertical. The SEOS has 45 degree vertical dispersion, even better.

I'll do some more research before cutting off the port extensions. Hopefully it will help.  The woofers are too difficult to remove to warrant measuring them, but I have two more that are hopefully from the same batch, and already broken in.
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 23, 2012, 10:46:27 AM
ok.... if we make it through the weekend with no baby, I'm coming over at some point this weekend to get a listen :)  I'll give you a buzz later....

Title: Re: Econowave Speakers
Post by: richidoo on March 23, 2012, 11:24:15 AM
That sounds good. Nothing in particular going on this weekend. Others are welcome to stop over too for a couple hours if so inclined.

I did remove the PVC port extensions. Wow!! What a gigantic improvement. The low notes got softer, more in balance now, but the howling in the low notes up into the midrange got much less. This is textbook response to shortening ports that are too long. When Carl was here he commented that they sounded like party speakers, a la Cerwin vega, etc. Speakers like that use too long ports to get more volume down low at the cost of tone quality and SPL in higher freqs, exactly what I was getting. I had noticed that the midrange frequencies were getting squeezed out by the overbearing bass and the adjustable horn. If I tuned down the horn to match the mids then the bass was 10dB too loud.

If this trend of improvement by shortening the ports can continue further, then I would want a little more of it, because the bass is still a bit too loud, so I will try to shorten them more. I can still hear chestiness in male vocals and cello, But the mids are totally clean now and the low bass is much improved. The bass is hugely punchy now, extremely dynamic, just like the horn. It reminds me of my old Legacy Focus 2020 which had +6dB bass response, although very musical and gentle, unlike this which is pretty intense.

Shortening the port further should also increase the midrange sensitivity, which means less horn attenuation and denser mids compared to the bass. I will try to find a sweet spot that retains some punchiness, while drying up most of the chesty roundness of the ports. Pretty cool  8)

I epoxied the PE ports to the box with very small amount of epoxy, then caulked them from behind, so I hope I can remove them to shorten. If not I have to find a way to shorten them in place, or make a mess of the box.
Title: Re: Econowave Speakers
Post by: Inscrutable on March 23, 2012, 12:26:23 PM
If not I have to find a way to shorten them in place, or make a mess of the box.
What kind of access to them do you have? I have one of those dremel Multi-Masters you might be able to use in tight quarters, or even a palm sander if you can get to the end of the port axially and have a lot of time on your hands.  :?
Title: Re: Econowave Speakers
Post by: richidoo on March 23, 2012, 12:50:48 PM
Thanks Tim. Good to know you are a tool collector too, never know when I might need a metric right angle widget remover.  

I got the ports out. As usual with my epoxy jobs, a firm tug will undo it. Actually, I only used small spots of epoxy hoping it could be removed in case of disposing of the boxes.

I'll figure some way to cut them on the table saw.

I'm listened to some tracks with no ports installed, just the 4.75" diameter, 3/4" deep hole in the plywood. The mids sound better, very detailed like the horn, fast and dense. No noticeable chestiness on male vocals.  YAY!! that's worth celebrating.
 :yay2:

The bass is still punchy, but not as low or intense as with the 4" long ports. And there is something weird about the sound of the bass now, kinda smeared tone, and it feels separate from the upper freqs. Sticks out like sore thumb. Could be the 4.75" dia. holes are too large diameter without the molded 4" ports in place. And definitely not as pretty with caulk remnants hanging out.
Title: Re: Econowave Speakers
Post by: richidoo on March 23, 2012, 12:57:07 PM
For anybody interested in some reading about port lengths:

Troels suggests that the standard port length calculations used in almost all software simulators are wrong, and the ports usually need to be shorter.
http://www.troelsgravesen.dk/vent_tuning.htm (http://www.troelsgravesen.dk/vent_tuning.htm)

http://www.ehow.com/info_8575773_effects-longer-subwoofer-port.html (http://www.ehow.com/info_8575773_effects-longer-subwoofer-port.html)

Obligatory sreten wisdom:
http://www.diyaudio.com/forums/multi-way/208509-shall-i-extend-shorten-length-port-if-i-want-more-extended-bass-volume.html (http://www.diyaudio.com/forums/multi-way/208509-shall-i-extend-shorten-length-port-if-i-want-more-extended-bass-volume.html)

Serious theory on how ports work:
http://www.hometheaterhifi.com/volume_5_2/cmilleressayporting.html (http://www.hometheaterhifi.com/volume_5_2/cmilleressayporting.html)

And another, even more technical
http://www.6moons.com/audioreviews/haigner/sidebar.html (http://www.6moons.com/audioreviews/haigner/sidebar.html)
Title: Re: Econowave Speakers
Post by: richidoo on March 24, 2012, 05:49:20 PM
Shane came today and gave them a qualified thumbs up. Good potential, needs TLC

I just swapped out the B&C DE250 compression drivers for the Radian 475PB. They need to break in, but initial impression is even more detail. Nothing offensive, but a lot of detail. They sound good so far, hopefully it will get even better.

Shane reminded me that I can tune the ports accurately by watching the port impedance peak using WT3. That will help. Removing the ports for cutting each time is a drag, so I want to make an adjustable length port so I can fine tune it in place. Not sure how to do that... any ideas? The inside surface should be smooth for the whole length. Maybe it doesn't need to be perfect just to find the right length. Like using cheap caps to find the right value then replacing with good ones.

I bought metal angle brackets to make some removable cross braces for the front baffle above the woofer. It is moving a lot without the braces and this is smearing lower midrange. Bracing the bottom of the woofer helped a lot, so this should too. Thinking about econobox 2.0.
Title: Re: Econowave Speakers
Post by: stereofool on March 24, 2012, 07:19:31 PM
Rich,
I think that I refered you to this site before, but I think that he has updated his crossover software.

http://www.bodziosoftware.com.au/ (http://www.bodziosoftware.com.au/)
Title: Re: Econowave Speakers
Post by: richidoo on March 25, 2012, 09:26:25 AM
Thanks Steve. 

I was a beta tester over the last 2 years for the just released Dirac Live speaker management room correction software. It uses both FIR and IIR filters were each is appropriate in the frequency range. Dirac is used in Bentley and BMW car systems and super high end theaters. They are finally offering a PC version for audiophiles.  No convolution hosts, it runs as a service in Windows. My next speakers will use it.

http://www.dirac.se/en/consumer-products.aspx (http://www.dirac.se/en/consumer-products.aspx)
Title: Re: Econowave Speakers
Post by: richidoo on March 25, 2012, 04:10:57 PM
I put the removable braces in to hold the top of the woofer. That cleaned up the lower mids a lot. Adjusting the port length and adding more stuffing still remain to optimize LF.

The Radian CD is breaking in nicely. It is strong in the treble, and extremely high detail, but low distortion of a CD so it is not fatiguing. It will probably need some adjustments to the xo to mate perfectly with this woofer. I don't sense any edge, acoustic instrument and vocal tone is excellent. But the treble is a bit strong for me.  I think it is flatter and more extended or maybe even rising HF compared to the DE250. It seems clearer and purer than DE250. It costs about twice as much.

I will do some measurements tomorrow to see where we are with FR and port tuning.
Title: Re: Econowave Speakers
Post by: richidoo on March 25, 2012, 07:20:27 PM
Thanks Doug. Yes it will be interesting.  Sounds like a nice sounding rolloff. It certainly has plenty of sizzle where it counts.

I did run a quick impedance sweep tonight to see just where the port tuning is now. See attachment.  It is at 29Hz, even AFTER I shortened the ports by almost 3 inches! It should be tuned to 38Hz! So that explains the sounds we're hearing, and why 1st iteration was a bass bomb with 7" long ports.  :shock:

I'll shorten them further to reach 38Hz, hopefully that will sound real nice.  8)
Title: Re: Econowave Speakers
Post by: Response Audio on March 25, 2012, 07:53:37 PM
Those are some very nice speakers Rich. Are you going to do any further finishing to the cabinets? Either way, they look sharp as they are. How's the monkey doing?
Title: Re: Econowave Speakers
Post by: richidoo on March 26, 2012, 08:29:47 AM
Hi Bill, thanks!!

I like the size and shape of them, and not too heavy...
I will stain and varnish them if I ever get them sounding how I want. Hasn't ever happened yet, but this one shows promise.

My daughter used to be a webkinz nut, she has about 60 of them. So everybody in the family has a webkinz monkey. Mine is named Thelonius, he is a jazz monkey.  8)  She made the "helmet" for him, it is for space travel, and protection while listening to my speakers up close.  :rofl:
Title: Re: Econowave Speakers
Post by: richidoo on March 26, 2012, 03:03:26 PM
Shortening the ports did not work. 2" port length tunes to 31Hz, but not 38Hz that I need. I must have made a mistake somewhere in my box design, because WinISD said I needed 7" and that sounded very bad. I will switch to Jeff Bagby's Woofer Box simulator as Face suggested. I gotta find my Office 2000 install discs first to install the Analysis Tookpak.  It doesn't run in OpenOffice.   
Title: Re: Econowave Speakers
Post by: richidoo on March 26, 2012, 06:48:17 PM
Found the disc (miracle) and have WooferBox up and running. Spreadsheet seems easy enough to use. Thanks Mike for the reminder about this.

Based on the work today I would be surprised if I don't have to build another box.  I need to check my numbers to find out what went wrong. I think the box volume is too big.
Title: Re: Econowave Speakers
Post by: mgalusha on March 26, 2012, 08:04:23 PM
Rich, I can plug the numbers into Winspeakerz if you like and see what it spits out.
Title: Re: Econowave Speakers
Post by: richidoo on March 26, 2012, 08:59:43 PM
Thanks a lot Mike, that will be interesting.

I used the Eminence published T/S specs into WinISD:
Fs = 37 Hz
Re = 5.04 ohm
Le = .46 mH
Vas = 147.2 liter
Qes = .44
Qms = 3.13
Sd = .052 m^2
Xmax = .005 m
Qts = .39

WinISD spit out max flat FR (attached) and specs for Butterworth ported alignment:
131.7 liters
38.3Hz
2 vents 4.02" diameter and 6.89 inches

I'll verify the T/S specs for my actual drivers. Could be they are too far off from the factory published specs I used, but that's not like Eminence.  I'll also verify the actual volume of my box. Could have been a snafu in the unit conversion or measurements.  But it will be interesting to see if WinISD and Winspeakerz agree about these numbers.

Thanks!!
Rich
Title: Re: Econowave Speakers
Post by: richidoo on March 27, 2012, 09:08:19 AM
I'm having trouble getting the WooferBox spreadsheet to work in Excel 2000. Everything works except all the graphs are blank. Toolpak is installed. Any ideas?
Title: Re: Econowave Speakers
Post by: richidoo on March 27, 2012, 06:34:41 PM
Got it working. Nice program.

I entered the specs, and it said use one 4"w x 3"L vent, or 2 4" x 7" (like WinISD.) But WT3 says the 4x3 port rings at 24Hz, not 37Hz like it should.  So I don't know what's going on. I verified volumes, but I did not measure the actual driver yet.

I am about to read vented box chapter in loudspeaker cookbook to try to gain an intuitive feel for what is supposed to be happening. Maybe get some simple formulas to do by hand. 

At least WinISD and WB seems to agree, so that means reality is the problem.  :duh
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 27, 2012, 07:26:36 PM
it's most likely differences in published versus actual T/S parameters...  I've met some drivers that were close, but not very many of them :)  they all tend to be quite a ways off the published spec in one way or another...  

AE TD12X woofers arrive tomorrow.  They shipped yesterday...

enjoyed the demo on Saturday... needs crossover tweaks and other things to really make them sing... but showed promise and didn't have the typical horn or pro sound that I typically hear and hate... a little too glassy sounding with Sol's amp... really sounded pretty darn good with the little AMR integrated to the point you could try to tune out the other issues with the frequency response and woofer/port issues... definitely the bracing you did likely took things up a notch as it was vibrating that front baffle a fair bit...... no need for big power for these speakers which bodes well for some of the tube stuff I have here :)...
Title: Re: Econowave Speakers
Post by: mgalusha on March 27, 2012, 07:42:25 PM
Rich,

I used the params stored in the driver database, which looked to be the same as the published ones. Output image is attached.

The port calculator said two 3" ports, 5.48" in length or one 4" port at 4.7" long. This shows a box tuning of 37Hz, which is where the predicted impedance saddle is, however the impedance peak is at about 67Hz, which should be the port resonance freq. This is all for a 3.24ft3 box.

Title: Re: Econowave Speakers
Post by: richidoo on March 27, 2012, 08:16:43 PM
Thanks Mike.   If tuning is 37Hz, should that coincide with the saddle  or the port peak? If it's the saddle I'm golden. I have been trying to move the port peak up to tuning freq.

WinISD beta doesn't model impedance at all. Woofer Box should model it but only the FR graph works on mine, and that took all day to fix.   I need to soak up some basic theory.

Thanks again for cranking that out.  :thumb:
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 27, 2012, 08:58:51 PM
...may not be here if painful contractions happening now are good sign of things to progress......

i suspect next time we here from you, there will be a new member in the sangster family...   congrats!!!   :thumb:

doug s.

looking like false alarm at this point based on it going away... we'll see....   she's sleeping now...  much better than needing to be massaged constantly :)

where are my manners.... thanks!  I'll be happy to greet the new addition when it happens... which hopefully is sooner rather than later at this point :)
Title: Re: Econowave Speakers
Post by: richidoo on March 27, 2012, 09:34:24 PM
http://www.diysubwoofers.org/prt/ (http://www.diysubwoofers.org/prt/)

This has some great info and advice for designing ported speakers. The spreadsheet simulator looks great too, and runs in OpenOffice ;)   Gives more advice of what to do, and compares 2 alignments side by side to help pick what is best for a given driver.

I agree about the actual T/S Shane, I need to measure the actual drivers. It is a pita to get them in and out of the box, but that's the price of beauty.

Eminence recommends 30-85 liters vented. So maybe the box is just too damned big, regardless of the simulators.

Advice from father of 3: get as much sleep as you can now.
Title: Re: Econowave Speakers
Post by: mdconnelly on March 28, 2012, 07:44:02 AM

...
Advice from father of 3: get as much sleep as you can now.

Shane, advice from father of 3 where all are now out of the house: doesn't matter what you do now, the next 18 years are going to be painful, awesome, difficult, amazing, stressful, and just incredibly rewarding.  Oh, and aging... it's definitely going to make you old.   

But there is hope!   Look at at all the fun Rich is having with these speakers *AND* being a father of 3!

Title: Re: Econowave Speakers
Post by: djdube525 on March 28, 2012, 08:42:21 AM
But there is hope!   Look at at all the fun Rich is having with these speakers *AND* being a father of 3!

Well... I secretly think Rich is either a robot, or has found a way to clone himself (http://www.imdb.com/title/tt0117108/).

 :rofl:
Title: Re: Econowave Speakers
Post by: richidoo on March 28, 2012, 03:01:14 PM
Well... I secretly think Rich is either a robot
shhhh, my secret....   ;)

I measured a real woofer and found some big differences. 

Published (http://www.eminence.com/speakers/speaker-detail/?model=DeltaliteII_2512)
Fs = 37 Hz
Re = 5.04 ohm
Le = .46 mH
Vas = 147.2 liter
Qts = .39
Qes = .44
Qms = 3.13

Measured
Fs = 46.43 Hz
Re = 5.034 ohm
Le = .885 mH
Vas =  ?
Qts = .44
Qes = .49
Qms = 4.485

I'm not thrilled about this. Free air resonant frequency is 30% higher than advertised. Inductance is 90% higher. That's bad. At least this explains why the ports don't work. The inductance being that far off is troubling.

I will measure the other three drivers I own and report back. They are all broken in for a year.  I've written to a tech guy at Eminence a few times. It will be interesting to hear what he says.

Shane, I'm glad your new drivers are on the way...  :thumb:
Title: Re: Econowave Speakers
Post by: richidoo on March 28, 2012, 07:03:41 PM
See attached chart of T/S specs on 4 samples.

At least they are consistent.  :D
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 28, 2012, 08:25:45 PM
AE TD12X woofers are here!  Two of them out of their boxes already and hooked up to AMR amp playing full range classical...  after a few hours they are starting to open up and play more extended, even if it is in free air with them sitting on the floor... interesting thus far...  I'll check the other one tomorrow hopefully...

Fs is *always* higher than spec.. or it just seems that way to me in all the drivers I've measured :)...  the inductance being higher as well is not surprising, but quite a bit higher than I would expect... yuck...

it's good that they are at least consistent in their inconsistencies :)  they'll likely try to pin it on the WT3 not being very accurate with it's measurements (it's not super precise, but it shouldn't be that far off like is shown in your measurements).  After that, they'll just say that the specs are an ideal and there is some implied variation that still meets tolerances... the Fs is likely within what they consider acceptable tolerances... but that inductance is really yucky...  not sure how they talk their way out of that one...

Sorry for you to find this out now... I didn't realize you modeled based off published specs instead of actual driver measurements.  I would have warned you.  Sorry!
Title: Re: Econowave Speakers
Post by: richidoo on March 28, 2012, 09:38:28 PM
I know to measure the actual drivers but I had read that Eminence was good with published specs blablabla whatever, I forgot to do it before it was too late. I can recalculate for a new box or fix this box for these drivers, but 48Hz resonance is crappy.
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 28, 2012, 10:07:10 PM
Hey,  I'm with you... there are tolerances, and then there is bald face lying :(  nearly 10Hz difference in Fs is not a small amount especially with these drivers in the design you're trying to pull off where every Hz counts to extend bottom end to the point of not needing subs...

they might try to tell you that the surrounds aren't loose enough since you don't play them at PA levels all the time to loosen them up enough to get those last few hz down....  I've not worked with a lot of high efficiency drivers before... but in lower efficiency home stuff I have measured, getting 10 more Hz in Fs extension is not something break-in related... maybe a bit more common in the pro world?  regardless, it stinks :(

I guess the only positive for them is that they were fairly consistent from unit to unit... just wildly optimistic on published values in relation to the real thing...  did you take weighted measurements for Vas to see if that is off as well? 

Again, sorry about the trouble, Rich.  I'm sure you'll have this licked and them singing even better in no time.   :thumb:
Title: Re: Econowave Speakers
Post by: richidoo on March 28, 2012, 10:15:45 PM
Finally someone up late with me!

No I have not done Vas yet. I was just reading up on how to do it so I'll run it tomorrow. I have a cool mini-scale to get accurate weight for the test.  Actually it came as a throw in when I bought the WT3, but I never realized how they were related.  :duh

I'm not pissed about the drivers, but I am a little pissed about the last two projects whose success was hampered because of me not knowing about the "tolerance." Live and learn.  

I can wire them in parallel and beat the hell out of them for a few hours with my homemade woofer torture track.  But I think you are right that the Fs will not descend very much. I do play low and loud quite a bit over a year's time.
Title: Re: Econowave Speakers
Post by: _Scotty_ on March 28, 2012, 10:37:17 PM
Rich, it looks like you have your work cut out for you. By my calculations, according to what you have posted about your box volume you have a box vol. of 91 ltrs. This is right at the upper limit of recommended box volumes. Another vote for VAS ? If you could accurately measure the VAS on the driver you might be able to feed the correct data into the software and find out if your box is way over the limit or not. If it is too large you can take up space in the cabinet by gluing in 2inch thick sheets of polystyrene blue foam insulation and using up air space in the cabinet with foam.
When I looked up the driver parameters I was kind of wondering how you were going to keep the driver from popping right out on to the floor when I saw the 4.9mm Xmax on it.
 I was reading Eminence's PDF doc on this driver and they recommend a Fb of 50Hz for a F3 48.12 Hz.
They also recommend a steep high pass filter set at 40 Hz to protect the driver from over excursion.
Here is a link to the Eminence PDF Doc
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-593# (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-593#)
At this point this project is starting to have a lot in common with a Gedlee Abbey only with a much larger box volume.
Good luck sorting this out we're all pulling for you.
Scotty
Title: Re: Econowave Speakers
Post by: richidoo on March 29, 2012, 06:41:48 AM
Thanks Scotty!! I agree, now that I know the real Fs, I'm surprised the things held together blasting Daughtry and Alice in Chains. Tough little buggers! But even with that torture, they answered my email quickly and suggested that I break them in. 30Hz for 30 minutes. Is it at the full 250W RMS rating, in free air? I think that will be extremely loud and stressful on the driver.

I calculate these boxes are 126 liters including all bracing and drivers installed. Outside dimensions are 14 x 18 x 42, w/ply 3/4" thick. No wonder it wouldn't tune to 38 much less 48.

I will measure Vas today, I am ready to go once I find a minute. Then I'll build new boxes for it, but not as fancy. I can use these large boxes for Shanes AE woofers. But I will measure them first. ;)
Rich
Title: Re: Econowave Speakers
Post by: _Scotty_ on March 29, 2012, 11:15:17 AM
Rich, due to the excursion limitations the driver has, I would base the power applied during break in on how far the cone moves. It would seem prudent to keep the excursion at or near the 4.9mm Xmax which is about 0.19 inch . This can probably be achieved with 10 watts or less given the drivers sensitivity. The actual power applied isn't important, staying inside the drivers absolute mechanical excursion limit of 8.3mm is.
 Unfortunately the drivers power rating is probably based on its performance in the midrange, and not its ability to safely play above 90dB below 100Hz. That is what those coffin sized subwoofers used on stage are for.
Scotty
Title: Re: Econowave Speakers
Post by: richidoo on March 29, 2012, 11:48:19 AM
Thanks Scotty, that makes sense. Published EBP is 84 but measured is 95, so you're right about the sensitivity is up higher.

I measured the Vas with 'added weight' method. See attached chart. 

I'll try to break one in for an hour to see if Fs changes.
Title: Re: Econowave Speakers
Post by: richidoo on March 29, 2012, 01:09:21 PM
Break in is helping. #1's Fs dropped from 46 to 41 after 30 minutes of my 40Hz+66Hz torture track.  I'll do some more until it levels out.

After a year you'd think it was broken in. But it really needs to be beaten hard.  11V rms is making the cone jump pretty big, but not hearing any bottoming.
Title: Re: Econowave Speakers
Post by: _Scotty_ on March 29, 2012, 02:47:21 PM
Rich, working from the factory supplied impedance curve and using ohms law it looks like
you are breaking the driver in with about 6 watts if the ~20 ohms at 50 Hz is correct.
 This assumes you have the driver laying on the floor with alligator clips connecting it to the amp. It will be interesting to see if the driver's Fs drops down to factory spec after you break it in.
Scotty
Title: Re: Econowave Speakers
Post by: richidoo on March 29, 2012, 03:43:26 PM
That sounds about right for power. I ran the 30Hz sine wave recommended by Eminence for a few minutes this afternoon before taxi service started up. The cone was moving even more than previous dual tone track. Eminence tech said that's what they do to warm up a driver before measuring it, 30Hz for 30minutes. Is it fair to assume that the amplitude is Xmax?

I didn't measure the voltage at the speaker, but I looked at the movement of the tinsel VC leads. I can see their peak positions and estimate the P-P distance. It is about a centimeter, maybe a hair more, which is 2*xmax.  If I turn it more, the tinsels start tapping the cone and it sounds bad, but still not bottoming, I think....

I am using my regular speaker cables with banana plugs since the drivers have 5way posts on them.
Title: Re: Econowave Speakers
Post by: richidoo on March 30, 2012, 10:37:19 AM
After 30 minutes of 30Hz at Xmax+ the Fs of sample 4 came down from 47.8Hz to 40.37Hz. I haven't measured the others yet.

(http://www.eminence.com/wp-content/uploads/staff-photos/AnthonyLucas.jpg)

Thanks to Anthony Lucas at Eminence for the instant response and good advice.
Title: Re: Econowave Speakers
Post by: hometheaterdoc on March 30, 2012, 11:42:34 AM
wow...  that's a big drop... I've seen 2,3, and a couple times 5Hz drop in FS once you work the surrounds and spiders pretty good to loosen them up... but for them to drop that much... wow... I guess those accordian surrounds are stiffer than i thought... definitely moreso than a typical roll surround.....

and it seems you never played them hard enough to really break them in...  I have a feeling if you leave them alone they will go back up in Fs over time....  something to consider I guess if you are using them in a home environment instead of PA where you really work them hard...

Hmmm... learn something new every day :)
Title: Re: Econowave Speakers
Post by: richidoo on March 30, 2012, 02:10:27 PM
I also manually pushed the cones to dead end in each direction. Bud Fried once said that loosens them up a lot, reducing break in time.

I think you're right, apparently they weren't hardly broken in at all, but I didn't measure them when new. They did sound drastically different when new and changed a lot over the first few weeks, but that was a year ago. So the new state would be interesting to measure compared to now. Hopefully my boxes are back in the ballpark now. Actually the simulation with unbroken drivers needed larger box, not smaller as I would have guessed. So it could work out well.
Title: Re: Econowave Speakers
Post by: richidoo on March 31, 2012, 02:44:04 PM
I measured them again after 30Hz, they are lower. But then I "massaged" the surrounds with my fingers and got the Fs to drop even lower, down to 35Hz for #4, down from 48Hz! After 3 hours of sitting still, Fs rose back to 37.7Hz.  I'll take it - I hope it stabilizes.

My wife said, "I wish you got that excited about massaging me!"
Title: Re: Econowave Speakers
Post by: richidoo on March 31, 2012, 03:26:26 PM
I am noticing a difference in measured Vas when driver is held vertically in the air with my hand versus when the basket edge is resting on a surface with my hand holding the top edge. The difference is about 1/2 cu ft Vas, and 5g (10%) of Mms.

I'll have to consult my D'Appolito "Measuring Loudspeakers" book as to which is correct, but since the driver will be held by a cabinet I would guess that the firm grip test method is correct. Which means I have to measure them yet again. But 3 are hovering around 37Hz after resting, one needed more massage because it went back up to 41. Hopefully it can be made to stay down.

The WT3 is starting to flake out. It would go quiet and record bad data during a session. I would have to stop the application and restart to make it work again. There is a new version of it with more features, but I wish you got more reliability for your $99 these days.

(http://www.enchantedlearning.com/asia/china/flag.GIF)
Title: Re: Econowave Speakers
Post by: richidoo on April 02, 2012, 02:42:58 PM
OK, sun is out, WT3 is working again, drivers remeasured after break in, Vas measured. All is right with the world again.

D'Appolito says that the Vas measurement is not that critical. My added-weight style measurements jibe with the factory spec so I'm going with it. A standard alignment box volume calculation is affected by Vas value, but I'm just going to not worry about it. If I build a new box I will construct a special box to allow measuring Vas directly.

Attached before and after T/S. looks good!
Title: Re: Econowave Speakers
Post by: richidoo on April 02, 2012, 03:53:48 PM
I thought that the port impedance peak was supposed to match the system tuning freq, but it is the frequency of the lowest impedance between the two impedance peaks that needs to match the calculated tuning freq. I don't think that I was far off from that when I was shortening the ports a week ago, so the bass may not get much better after all.

I picked driver #2 and 4 for their similarity to go into the boxes. I used the average T/S values from these two for the sim. Woofer Box says 1 port 2.5" length, or 2 ports with 8" length. 2 ports at 8" is very close to my original simulation with 7" something ports. So all I really needed to do was break in the drivers. But can't measure the drivers in the box.

I should be able to get it reassembled tonight or tomorrow.  

EDIT, learned that the volume of the ports should not be included in the box volume. So my internal volume with drivers braces and ports subtracted is 116 liters, significantly different from the original 131 liter I was using in WinISD while using published specs. 2 ports at 8.4" is predicted now, close to 7.9" of the original.
Title: Re: Econowave Speakers
Post by: richidoo on April 03, 2012, 10:47:36 AM
Playing them now with just the two 5.75" holes in the plywood for vents. So this makes 121 liter box, tuned to 81Hz. It sounds much better than before the drivers were broken in. The bass is still a bit too much, but not too distracting. Installing the calculated 8" vents tuned to 37Hz will just bring back the giant boom. This has a lot of punch, and OK bass tone, unlike before breakin. Midrange is slightly lean if you know what it's supposed to sound like, but not distracting. A huge difference from when I tried this setup with unbroken drivers.

I think that the standard butterworth alignment is just too big for these drivers. So I'm looking at the Eminence design, 85liters, Fb 50Hz to reduce the overall amount of bass to make a better balance, and I presume it will make the midrange a bit louder too. I think I'll try Scotty's idea of killing volume by stuffing with hard foam. That will allow incremental adjustment and experimentation to find the best volume. I need to kill about 30 liters, to hit the eminence 3cu. ft. There is almost enough space below the ports in the bottom of the box for that.

Adjustable port length would be helpful...

I also learned that my ports are too close to the side walls. Ideally they should be mounted vertically in the center of the front baffle, or closer together.  When I make the next, final version box, I can use PVC pipe for ports, which will allow them to be much closer together and remain horizontal orientation which looks better than vertical, imo.

This big box will be good for sealed alignment with Qtc .56
Title: Re: Econowave Speakers
Post by: _Scotty_ on April 03, 2012, 11:22:58 AM
Rich, if your ports are an inch away from the side walls they will still work.  Don't sweat the small stuff.
If you can measure what is going on with the drivers actual driver output at about 150 Hz this would tell us what its intrinsic output level is relative to the compression drivers output at or near the xover frequency.
 I am wondering if the added voice coil inductance has depressed the woofers output relative to the tweeter at the xover and if you are in part listening to a trough in the midrange as well as a peak in the bass due problems with box volume and tuning.
Scotty 
Title: Re: Econowave Speakers
Post by: richidoo on April 03, 2012, 06:07:12 PM
Thanks for your advice Scotty!

I was thinking the same thing about the woofer rolloff/higher Le. I will measure the FR of everything tomorrow.

Do you know how it is possible for Le to be so far off? Mine are 90% over, and I measured another driver today whose Le spec was exceeded by almost 500%.  Seems like you count the # windings on same diameter former and it should come out the same everytime. (We need one of those scratchy head emoticons.)

I haven't responded to Eminence yet about the breakin fixing almost everything, because I wanted to see if the high Le was going to be useable before I ask for a fix. I doubt I'll get it, but  worth a try. 7 year warranty is there for a reason.
Title: Re: Econowave Speakers
Post by: _Scotty_ on April 03, 2012, 08:04:13 PM
I believe it's called "we reserve the right to change specifications and designs without notice at anytime in order to improve performance or our bottom line",
or something very much like this.
 Your inductance measurements can vary greatly depending upon the frequency at which it is measured, this may be a partial explanation. Have any drivers you measured met published specs?
I don't know if your design calls for a zobel network on the woofer and the tweeter, if you don't have the networks in place the crossover will not behave the way it is supposed to and the speaker won't sound right either.
Scotty
Title: Re: Econowave Speakers
Post by: richidoo on April 03, 2012, 09:20:00 PM
That's a good point, inductance varies with frequency. I'll check with the mfgs at what freq they spec Le. Usually 1k, I think. WT3 just gives one number.

The original Econowave Delite design by Zilch  has no impedance correction, but they discussed it in the design thread, and it didn't appear in the final circuit. I assume Zilch tried it and thought it unnecessary. I can design correction if necessary. I have not gotten into that yet because correcting impedance will upset the compromises chosen to achieve flattish FR without zobels. I wanted to get the bass settled first. And the mid and crossover region does sound pretty good as it is. Shane and I assume there will be need for EQ in the final tuning, but impedance correction and slight filter adjustments might be all that's needed if the drivers are well behaved.

I'm attacking the worst problems first, which was the bass. I've learned a lot in the last month, things are starting to  move forward now, I think.

Designed crossover at 1500Hz:
(http://techtalk.parts-express.com/attachment.php?attachmentid=8028&stc=1&d=1270676492)

Impedance for my woofer and horn attached below.

This is the impedance plot for the DE250 for which the crossover was designed. The new CD has flatter impedance and sounds better, without impedance correction.
http://www.parts-express.com/pdf/294-605.pdf (http://www.parts-express.com/pdf/294-605.pdf)
Title: Re: Econowave Speakers
Post by: richidoo on April 04, 2012, 08:51:13 AM
Here's some measurements.

Crossover appears to be at 1.4kHz, that's acoustic not electrical.

Blue is whole speaker 15" from center height between horn and woofer. 

Light blue is mic buried deep inside tweeter horn (twss). Note the dip at 8kHz. Mic is surrounded on 5 sides with horn. Internal horn reflection? Woofer is also playing during this test.

Red is woofer with mic 1" from dustcap, and horn pot turned all the way down. I can still hear some horn though, but very low. Note the dip at 1kHz.

Green is a single port, mic centered in diameter and port length. Horn volume minimized.

SPL levels are not proportional, ignore relative SPL levels of lt blue, red and green.

Graphs Attached.
Title: Re: Econowave Speakers
Post by: richidoo on April 04, 2012, 09:09:02 AM
Looks like the high voice coil inductance of the woofer is rolling off SPL before it rises to the crossover frequency. :(

Zilch's measurements show the woofer FR peaking at 550Hz. Mine peaks at 100. Premature peak. I hate when that happens. :(

Also looks like the Radian CD I am using now is crossing at a bit too low freq. This crossover is designed for B&C DE250, so this was expected. Of course the filter response is determined by its load, and these two CDs have very different impedance in this range, so impedance correction could help. But raising the filter freq would be better since Radian impedance is much better behaved than the DE250.

The predicted port resonance was 81Hz, but it peaks at 60Hz. Probably explained by my errant Vb estimates, and likely  incorrect Vas spec.

Nice to see all these problems on paper, even though the speaker sounds musically enjoyable now. More worms on the hook for me, hoping it can get even better.
Title: Re: Econowave Speakers
Post by: richidoo on April 04, 2012, 12:22:10 PM
Attached is the free air frequency response of my #3 woofer compared to Eminence published FR.  The rolloff is obvious. I wrote back to Eminence to see what they say.

I can move the crossover lower, but it would need to be 500-600Hz lower, which puts CD too low and into its resonance band.

My next speaker will be a 3way with these used for bass, so it's not end of the world if Eminence gives me the bird, but I'd like to be able to use them in econowaves too.

In the future I'll purchase from Parts Express and measure immediately, so I can return them within 45 days if they are off.
Title: Re: Econowave Speakers
Post by: _Scotty_ on April 04, 2012, 06:46:39 PM
Rich, the droop in the response curve above about 800Hz is most likely primarily caused by the Mms being higher than the specified 49gr..
The less than 1mH of voice coil inductance contributes to the downward slope but it by itself will not give you a roll off of this magnitude but adding in the effect the moving mass will.
 It's academic at this point but I am curious just what the Mms is on these drivers.
Scotty
Title: Re: Econowave Speakers
Post by: richidoo on April 04, 2012, 07:41:32 PM
Thanks Scotty...
WT3 says Mms ranges from 44.1-45.5g, found while doing added mass Vas test. I think I used too much mass for the Vas test, I used 48g, because some website said use ~same weight as published Mms, but John K says use about 60% of Mms. I'll just build a Vas box to do them again. Learning to measure drivers takes some time and mistakes.

I've been trying to figure out how to derive inductance from  impedance and DCR, using info in this post:
http://www.pupman.com/listarchives/1996/may/msg00062.html (http://www.pupman.com/listarchives/1996/may/msg00062.html)
but I'm having a little trouble solving for L with the impedance formulas. Me and i have never hit it off. I'd like to make an Excel chart with impedance data exported from WT3 and calculated inductance plotted by freq, but I need to figure out the formula for L.

The quicker rolloff means that the Zilch crossover won't work perfectly with my woofers, so I have to make new crossovers from scratch. That's fun for me, and I took on this project knowing we would change things requiring crossover tweaks, and it is just a step toward learning crossover design. But some ewave builders might not appreciate the needed design skills if the drivers don't match the prototype. So buy from returnable supplier like Parts Express, and measure them immediately, or just do what Zilch wanted you to do, learn to use PCD to develop your own crossovers from scratch, AFTER you measure your drivers.
Title: Re: Econowave Speakers
Post by: richidoo on April 08, 2012, 06:18:35 PM
Sol came over yesterday, to verify the Le of a couple different drivers that seemed on the high side according to WT3. The Eminences are indeed on the high side as reported by WT3, the others are false alarm - WT3 is wrong on those. Shane's AE TD12X are very low impedance for a wide band - Awesome!! It will be very easy to make crossovers for these.

I finally figured out the box tuning for the Ewaves.  :yay2:
In 121 liters of this box, two ports of 4"D x 5.25"L makes 38Hz as required by the driver and box volume as measured. The Woofer Box simulator says it should be 8" ports, go figure.

So I cut PVC pipe to extend the flared plastic 4"L ports I have and glued them together. Tomorrow I will install into the speakers. I may want to add more fluff, but otherwise the bass is done. I've listened to only one speaker, but it sounded good.

Next up is measuring the drivers in the box, and designing a crossover to better suit these woofers. I plan to lower the LR2 crossover a little bit if possible while staying away from tweeter resonance. Also experiment with impedance correction, baffle step correction, air core woofer coil.

The other possibility is 1st order with just a cap on the CD, since the woofer breakup is pretty tame due to the higher Le. With lemons make lemonade. But it will spoil the controlled directivity of the woofer to let it play up too high and beam, and the power handling of the horn with shallow high pass is a concern. But easy to try it out.
Title: Re: Econowave Speakers
Post by: richidoo on April 09, 2012, 09:36:47 AM
With the ports installed the bass is quite nice, punchy but clean. But something in the midrange is off. I have not measured FR yet. I am going straight to the crossover work. 

I am trying to enter the data needed to simulate crossover in PassiveCrossoverDesigner. It requires impedance file (*.ZMA) and a Frequency Response Data (*.FRD.) I exported the ZMA right from WT3, but I'm having trouble with the FRD file.  How do I create this?

I have REW, but its exported SPL files don't have any phase data. How do I create a FRD file from my own driver?

Thanks
Title: Re: Econowave Speakers
Post by: richidoo on April 09, 2012, 09:49:56 AM
I'm gonna give this free product a try:

http://www.holmacoustics.com/holmimpulse.php (http://www.holmacoustics.com/holmimpulse.php)

It says it can include phase in the SPL measurement export.
Title: Re: Econowave Speakers
Post by: richidoo on April 09, 2012, 01:51:25 PM
After a few hours listening I pulled out the ports. Still too much bass and it's making the mids sound dull or too soft. The speakers just went dead, no presence. I think I just hate the sound of ports. I have heard some speakers make good use of them, but they pointed away from me, and I think there is only so much I can get out of these Eminence drivers. Not sure what's up at this point.

I have the ports totally sealed up now. Qtc is ~.56. Bass is much more natural and realistic, less exaggerated punch. The midrange weirdness is gone.

I have always intended to build sealed box anyway. This ported detour is to make a portable speaker with good bass.

Eminence offers several designs for this woofer. The largest box is 78 liters vented. I'll try their exact recipe before moving on.
Title: Re: Econowave Speakers
Post by: BobM on April 10, 2012, 06:30:21 AM
Sometime in the future you may want to try a slotted port rather than a circular one. There is a slight difference in what the port produces this way, but probably no difference in how the speaker itself responds to either port.

I tend to think of ports this way, they seem to help drivers 8" and smaller reach down deeper, but don't work so well for larger woofers. I think a 10"-12" or bigger driver benefits more from a sealed cabinet and the air-support-suspension it brings to the driver cone.
Title: Re: Econowave Speakers
Post by: richidoo on April 10, 2012, 01:05:57 PM
You might be on to something Mr Bob!
Title: Re: Econowave Speakers
Post by: richidoo on April 12, 2012, 01:01:10 PM
I wore out my WT3. The signal output strength just fades away while testing, and sometimes fades back in, sometimes not. Dayton Audio standard 5 year warranty should get me a replacement with the new version. Still looks the same, but hopefully the reliability will be better, along with the new features.

Here's some links about how to measure loudspeaker T/S parameters manually, with spreadsheet to do the calculations:
http://sound.westhost.com/tsp.htm (http://sound.westhost.com/tsp.htm)
Measuring Le is not described. So...

Here's an article on what "effective" voice coil inductance (Le) really is and why it is difficult to measure on loudspeakers.
http://www.diy-audio.narod.ru/litr/Le.pdf (http://www.diy-audio.narod.ru/litr/Le.pdf)

Update on the speakers:
Nothing new. I need a break from thinking about this. The box even when sealed vibrates with lower mid frequency tones, muddying that band. Not unexpected for a plywood box. The braces are not as effective as they need to be. So I am planning a new box construction to improve the low-mid resonances. I will be trying a foam sandwich construction which should be extremely stiff and light. Plus design in a lot more internal cross bracing than this last one. It will not be pretty, but hopefully it will work, or teach me something.

I was inspired by all the recent success with this project to look at a nice pair of Revel M22s on Agon today. I thought, "Why can't I be like all the other kids?"

Shane wisely suggested that the new port length and bass sound might actually be correct, but the rolled off inductance of the woofer is leaving a hole in the FR near the crossover, making the bass seem out of balance.

I am sending one driver to Eminence for measurement on their LMS system. Eminence measured a current production sample for me and got .48mH, almost perfect. LMS generates a inductance curve across frequency, but I don't know what frequency is chosen for their published Le. Just like a crossover coil, inductance varies with frequency. The WT3 sampled my drivers at 1kHz, we verified that on Saturday. But it's still based on WT3's impedance measurement which might be hosed since the unit it on the blink. But I don't think so. When it works it seems fine. 
Title: Re: Econowave Speakers
Post by: Inscrutable on April 12, 2012, 02:59:54 PM
Rich
Just to take the box vibration out of play, have you thought about temporary external bracing? You could even go so far as to make an outside form and fill with grout.

Sorry this has turned into one of MY home improvement projects  ](*,)
Title: Re: Econowave Speakers
Post by: richidoo on April 12, 2012, 03:53:34 PM
That's a pretty good idea, entomb it in cement! I've tried attaching exterior mass before, it doesn't work. Only stiffness works. I'm excited to build the foam sandwich. I've built a lot of plywood boxes, interested to see if something new will work better.

The box color is not so bad. It's far less than the econowave prototype made with no bracing at all.

Sol reminded me that I can cure the woofer crossover by reducing the coil to it to bring it up a bit. So it just needs a custom crossover and it will be better. The 1500Hz crossover point is not for benefit of the tweeter, it can cross much lower. It is to maintain horizontal dispersion (90 deg) with the horn at the crossover freq.  This driver can do that even with the high Le.
Title: Re: Econowave Speakers
Post by: djdube525 on April 12, 2012, 04:21:02 PM
Rich
Just to take the box vibration out of play, have you thought about temporary external bracing? You could even go so far as to make an outside form and fill with grout.

Sorry this has turned into one of MY home improvement projects  ](*,)

I was thinking the same thing... add essentially a bunch of "ribs" or "furring strips", Then another layer of plywood, then fill the voids with sand...
Title: Re: Econowave Speakers
Post by: richidoo on April 12, 2012, 04:44:15 PM
OMG that would weigh a ton! But it should be a sound improvement. I'll try to find a pic of one that I built like that, without the sand.
Title: Re: Econowave Speakers
Post by: richidoo on April 16, 2012, 12:12:01 PM
Eminence measured one of my woofers at their factory. LCR meter shows .457mH, spec is .46.   Then he measured impedance and SPL with LMS tester and they are also within spec. So I need to get better measurement tools and/or better understanding of driver measurements.

Thanks again to Anthony Lucas at Eminence for patience in answering my questions and testing my woofer. Great service from Eminence!

Edit: Parts Express is replacing my broken WT3 with the new version under warranty. Should be shipping today. I hope my measurements will improve with the new one, but I'm setting up a manual test rig for verification.
Qms, Qes and Vas determine box volume (Vb.)
Qms, Qes and Fs determine box tuning frequency (Fb) and consequently, port dimensions.

Anthony replied that my 121liter box tuned to 38Hz is too big and too low for the driver. Their biggest recommended vented design is 78 liter, 50Hz.

I have to wonder if the free simulators are worth their price, and whether a fancy sim like LEAP5 would do any better? Eminence recommended boxes are designed using their own Eminence Designer (http://eminencedesigner.com/) product to get numbers very different than my sims, even when I use the factory specs.

Edit2:  I think the box is stiff enough. I think the new "box noise" I heard after sealing the ports is LF echo coming through the driver cone, because there is only minimal stuffing in the speaker. For sealed there should be a lot more to kill the interior echos.  It doesn't do that when ported.
Title: Re: Econowave Speakers
Post by: richidoo on April 17, 2012, 07:03:04 AM
Old school vented box design:
http://users.ece.gatech.edu/mleach/ece4445/downloads/ventedbox.pdf (http://users.ece.gatech.edu/mleach/ece4445/downloads/ventedbox.pdf)
Title: Re: Econowave Speakers
Post by: richidoo on April 19, 2012, 06:17:12 PM
I put Shane's AE TD12X woofers into my econobox. Simon at AE forum said it likes a big box. It has godalmighty power even with tube amp, and more LF detail than the Eminence, but it's still too loud and rumbly because the box is tuned too low. I think the box is just too damn big for either driver. In the right size box this AE will be truly awesome. 

So now I'll fill in the bottom of this box to kill off some volume. I can fill up to the bottom of the ports, then stick in some other blocks in the remaining space if necessary. I think filling in the bottom section up to the ports will get my volume down to the Eminence recommended volume of ~80liters. I think I'm around 115-120 now.

When the tuning is too low the midrange really recedes. This is described in some of the literature I've read.
Title: Re: Econowave Speakers
Post by: richidoo on April 21, 2012, 06:23:03 PM
Bottom is filled in with spray foam up to the bottom of the ports. Probably took out about 30 liters. Ports are still 4 x 5.25". Should be correct for the Eminences, according to their own cabinet plan.

It sounds a little better with the AEs in there, but still a little bottom heavy. I would guess that they AEs will need shorter ports, maybe even smaller box, as simulations predict.
Title: Re: Econowave Speakers
Post by: Face on April 21, 2012, 07:05:23 PM
If they're still bottom heavy, they may need a longer port, not shorter. 
Title: Re: Econowave Speakers
Post by: rollo on April 22, 2012, 07:28:05 AM
   Would a passive radiator have an affect reducing vibration into bass ?  Did you use any viscoelastic dampening [ black hole pad ] material between driver and box ?


charles
Title: Re: Econowave Speakers
Post by: richidoo on April 22, 2012, 07:36:40 AM
If they're still bottom heavy, they may need a longer port, not shorter. 

Thanks Mike! Won't that lower the tuning freq? I am under the impression that it is already too low.

Based on Simon's advice I am ignoring the simulations for TD12X that say 48litres, but I think the sims are more correct than wrong. 120 and 85 liters sound too boomy. To me that means box too big or port tuned too low. The Fs of these two drivers are 25 and 30Hz.

According to eminence simulation this volume and port should resonate at 50Hz with the Eminence driver.
Thanks Mike
Title: Re: Econowave Speakers
Post by: richidoo on April 22, 2012, 07:42:53 AM
Would a passive radiator have an affect reducing vibration into bass ?  Did you use any viscoelastic dampening [ black hole pad ] material between driver and box ?

Hi Charles. PR would be an interesting alternative. Scares me to think about designing a PR based on my current reflex port record.

There is a rubber gasket between the AE and the box. There is a soft paper gasket between the Eminence and the box. No black hole inside the box, just a 1" layer of FG on all interior surfaces.
Thanks Charles!
Rich
Title: Re: Econowave Speakers
Post by: bpape on April 22, 2012, 08:02:28 AM
The beauty of a PR is that you can simply add/subtract weight from it to change the tuning.

Much easier than cutting and gluing ports all the time.

Bryan
Title: Re: Econowave Speakers
Post by: Vapor1 on April 22, 2012, 08:47:17 AM
I bet you'll have some trouble finding a 12" PR that will tune as high as you want. 

I haven't read the entire thread, just bits and pieces.  But my impression here is that you're blaming the box when in actuality, the blame likely lies with the drivers themselves.  The Ewave isn't a refined, integrated, high resolution speaker.  It just isn't, those drivers just aren't capable of delivering that presentation.  They're decent at all those things, but lacking ultimately. 

Could you do me a favor and post a current status of the project?  What you're looking to improve, and what exactly your configuration is?  I might have some ideas.
Title: Re: Econowave Speakers
Post by: richidoo on April 22, 2012, 12:17:42 PM
Viper, I don't agree with your opinion of the Eminence DeltaLite II 2512. It has excellent "resolution" at crossover frequency, and at LF when in a sealed box. Of course there are better drivers available, but this is adequate for what I'm after now.

As for econowave lack of refinement, this is not cookbook econowave. Right now I have AE TD12X, Radian 475, Jantzen caps, Erse SuperQ bass coil. LR2 ~1400Hz with pad on tweeter. 1.5" pink FG bat on walls of well braced box. Vb 80 liters, two ports 4Wx5.25"L. Bass is way too boomy and smeared. It improved slightly by reducing Vb from 120 to 80l.  But this box config is the Eminence published design for the 2512. I'll put the Eminences back in tomorrow. They are internal mount, so it's a big job to swap drivers.

I tried the AEs in the box when it was 120l and now 80l because AE moderator said the simulated Vb of 48l is too small, and 120l would be good.

Eminence says that simulated standard alignment of 120liter is too big for 2512 driver. Between the sims and the advice I am spinning wheels. I wish reflex design was more scientific, but it seems like more of a crap shoot or trial and error.

You'll have to read the thread to see how I got to where I am at the moment. I am not at an impass, I'm just reporting my progress.  
Title: Re: Econowave Speakers
Post by: Face on April 22, 2012, 03:25:37 PM
If they're still bottom heavy, they may need a longer port, not shorter. 

Thanks Mike! Won't that lower the tuning freq? I am under the impression that it is already too low.

Based on Simon's advice I am ignoring the simulations for TD12X that say 48litres, but I think the sims are more correct than wrong. 120 and 85 liters sound too boomy. To me that means box too big or port tuned too low. The Fs of these two drivers are 25 and 30Hz.

According to eminence simulation this volume and port should resonate at 50Hz with the Eminence driver.
Thanks Mike
You need to measure to see where the boom is.  If it's ported too high, you'll have a large peak in bass response too. 

As for PR's, they're a great alternative when a very long port would be required. 
Title: Re: Econowave Speakers
Post by: richidoo on April 22, 2012, 03:47:22 PM
Makes sense. I'll do it.
Thanks
Title: Re: Econowave Speakers
Post by: richidoo on April 23, 2012, 03:24:57 PM
I didn't do it...  :^o

I decided to pursue the AEs in a new project, so they don't further confuse the current effort.

I swapped in the Eminence drivers today. The box and port dimensions now match the Eminence large ported box design. Sounds much better. Still a bit too punchy for my taste, but much cleaner, the boom is much reduced. When the new tester gets here I'll tune the port length to 50Hz. It sounds tuned lower than that now.

I've also been pulling FG out of the box a bit at a time to open it up. Midrange sounds too restrained, muffled. It's getting better.
Title: Re: Econowave Speakers
Post by: richidoo on April 24, 2012, 03:15:17 PM
I had too much FG stuffing in the box, it was damping midrange transients too much, and attenuating midrange too much. I'm pulling it out bit by bit and it is opening up. :)  The bass might be OK as is, if the midrange continues to come up some more.  I've removed only 1/4 of the FG so far.  

What's something less absorptive I can use to replace it? Black hole, NoRez? Parts Express Sonic Barrier? Gotta be cheap.
http://www.skiingninja.com/Articles.asp?ID=157#norez (http://www.skiingninja.com/Articles.asp?ID=157#norez)

Edit: I forgot that I had turned the Sonos bass EQ down by 8dB. When set to flat the bass is still waaaayy too much.  :-k

FG reduced to about 1/3 of original, focused around and near the woofer. It sounds more open, no downside that I can hear yet.
Title: Re: Econowave Speakers
Post by: Face on April 24, 2012, 05:12:09 PM
Do some nearfield woofer measurements to see where the issue is.  Could also be placement/room related. 
Title: Re: Econowave Speakers
Post by: richidoo on April 25, 2012, 09:14:15 AM
Mike, here's the FR of two speakers. Blue is left, red is right, no smoothing. Right is closer to a sidewall. Mic height between horn and woofer, 1meter from front baffle. Ports installed.

Dip at 200Hz?
Title: Re: Econowave Speakers
Post by: richidoo on April 25, 2012, 09:30:38 AM
At couch, 3.3 meters.  

Maybe the dip at 200Hz is the problem.  It's amplitude 6-8dB equals the EQ I need to apply to bass control to balance the sound.

Fb is supposed to be 50Hz now, according to Eminence. My Fs are at factory spec so the tuning should behave as their sim predicts. New WT3 is shipped but not here yet so I can't measure the impedance to see the exact Fb.
Title: Re: Econowave Speakers
Post by: richidoo on April 25, 2012, 05:54:49 PM
This post (http://www.diyaudio.com/forums/multi-way/46281-my-box-too-big-4.html#post1213351) from AndrewT on diyaudio is interesting. The eminence Qts is .39. Perhaps Viper is right, the Eminence is not ideal for ported box outside of PA duties, and maybe I am expecting too much from it. It sounds great in sealed, so I'll look into that for the Eminences, or just sell them.

The AE's have published Qts .28, so that's well within ported territory.

Face, you are right, longer ports reduce the boom, not shorter. I don't know where I picked that up.

Also more stuffing, not less to reduce the boom, but transient response at midrange frequencies suffers with too much stuffing.
Title: Re: Econowave Speakers
Post by: Face on April 25, 2012, 06:23:47 PM
The 200hz dip is probably floor bounce, completely normal.

As for measuring LF extension, you should measure the woofer up close, only a few inches away.  It should take room gain, floor bounce, and other reflections out of the equation. 
Title: Re: Econowave Speakers
Post by: richidoo on April 25, 2012, 06:36:44 PM
Floor bounce, yes that makes sense. Thanks.

I'll do woofer Fr again tomorrow up close

Will that still allow for the port contribution? I guess port radiates omni.
Title: Re: Econowave Speakers
Post by: _Scotty_ on April 25, 2012, 06:47:45 PM
Rich,measure the port and then measure the woofer and splice together the two curves.
Scotty
Title: Re: Econowave Speakers
Post by: richidoo on April 26, 2012, 07:01:08 AM
Thanks Scotty. I can't splice with REW5, but I can overlay. See attached. Recording level is the same for both sweeps. Mic at center of port exit and 1/2" from center of woofer.

Looks like I should be quite happy with these results, but bass is too punchy and seems too loud. Should I lengthen the ports or just move on to the sealed box that I prefer? Ported speakers that I have owned in the past were rear ports, these fire foward.
Title: Re: Econowave Speakers
Post by: richidoo on April 26, 2012, 07:37:50 AM
I played with WinISD again. I simmed the Eminence design that I am trying to copy now. See attached. This is what Eminence recommends for this driver. 78 liter box with two 4x5.5" ports, Fb 50Hz. WinISD predicts 54Hz Fb. Notice the 2+dB bump. This is also shown in Eminence published design. See attached green curve.

My ports are a little shorter, and I don't know what the exact volume is of mine with the foam fill as there are some small voids for air to go, but mostly solid and probably larger than 78l. If I sim 90l with my ports I get 50Hz and the bump  is a little less than 2dB. But measuring the port gives SPL peak at 42Hz which puzzles me. Am I confusing port resonance with Fb? Are they the same or different?

Now if I lengthen the ports to 12" to bring the simulated Fb down to 40Hz, the red curve flattens out which is what I want.  But since the actual tuning is much lower than predicted, will lengthening bring the actual measured port resonance down too low?  

I could also remove the foam to increase the volume, and lengthen the ports but Eminence says 120liter is too big, even though sim predicts it as max flat alignment.

I don't want to do the 12" ports unless there is a chance for improvement. What do you guys think?

The 4th option is to bag these ported Eminences and move on to the ported boxes for AE TD12X for Shanes speakers. I plan to use the Eminences in sealed active speakers for myself anyway.
Title: Re: Econowave Speakers
Post by: rollo on April 26, 2012, 07:50:04 AM
  Ah to port or not to port. I would give it one more try with the longer ports. Just make shure they are as rigid as possible.
 If all fails than a bottle of Port may do the trick.  :rofl:, Do not give up the Ship yet, you have worked hard so far to get where your at.
   If anyone can help Scotty is the one. Got to hear his rig and he has it going on in spades. Knows his speakers.


charles
Title: Re: Econowave Speakers
Post by: richidoo on April 26, 2012, 08:58:38 AM
Thanks Charles, yes I agree. We have some great experts here on AudioNervosa. Thanks to everybody who has pitched in along the way.
Title: Re: Econowave Speakers
Post by: Face on April 26, 2012, 11:09:56 AM
I played with WinISD again. I simmed the Eminence design that I am trying to copy now. See attached. This is what Eminence recommends for this driver. 78 liter box with two 4x5.5" ports, Fb 50Hz. WinISD predicts 54Hz Fb. Notice the 2+dB bump. This is also shown in Eminence published design. See attached green curve.

My ports are a little shorter, and I don't know what the exact volume is of mine with the foam fill as there are some small voids for air to go, but mostly solid and probably larger than 78l. If I sim 90l with my ports I get 50Hz and the bump  is a little less than 2dB. But measuring the port gives SPL peak at 42Hz which puzzles me. Am I confusing port resonance with Fb? Are they the same or different?

Now if I lengthen the ports to 12" to bring the simulated Fb down to 40Hz, the red curve flattens out which is what I want.  But since the actual tuning is much lower than predicted, will lengthening bring the actual measured port resonance down too low?  

I could also remove the foam to increase the volume, and lengthen the ports but Eminence says 120liter is too big, even though sim predicts it as max flat alignment.

I don't want to do the 12" ports unless there is a chance for improvement. What do you guys think?
Ports are cheap.  ;)

FYI, they may not recommend a larger box due to you running out of x-max quicker.  But in a hifi environment, you may be fine. 
Title: Re: Econowave Speakers
Post by: richidoo on April 26, 2012, 12:56:22 PM
OK, then I'll try longer ports. Thanks Mike

So the design process is:
measure the driver,
simulate box as a starting point.
Build the box,
tune port length and stuffing by ear.
Don't tune port length to simulated Fb.
Ignore the simulation as much as possible for sanity.

Is that what you do? Mike? Scotty? Others?  I'd love to hear your design approach to a ported box. Thanks!

Is Xmax the only reason to limit port length, or is driver resonance a barrier also? (for max flat)

Thanks
Rich
Title: Re: Econowave Speakers
Post by: Face on April 26, 2012, 01:06:35 PM
OK, then I'll try longer ports. Thanks Mike

So the design process is:
Measure the driver.
Simulate box as a starting point.
Build the box.
Tune port length and stuffing as simmed, leaving ports a little longer than recommended.
Measure nearfield.
Fine tune stuffing and port length by measurements and ears
This is what I do...and using this program: http://audio.claub.net/software/jbabgy/WBCD.html (http://audio.claub.net/software/jbabgy/WBCD.html)  
WinISD is a toy in comparison.  ;)  

You may find this helpful as well: http://audio.claub.net/software/jbabgy/BDBS.html (http://audio.claub.net/software/jbabgy/BDBS.html)
Title: Re: Econowave Speakers
Post by: _Scotty_ on April 26, 2012, 01:31:16 PM
Rich, what we can't see from your measurements so far is any evidence of a pronounced peak in the output of the speaker at or near the tuning frequency.
 What we do know is that you have a depressed midrange, psychoacoustically speaking you have speaker with a loudness contour curve built into it.  I can't see how the bass can sound right to you when it is boosted relative to the midrange.
 I would be tempted to try measuring the speaker outdoors with it sitting on chair to raise it off the ground. This would lessen the effects of any room boundaries on your perception of how the speaker sounds and possibly improve your measurement accuracy.
 As far as stuffing goes I have had much better results from using cotton furniture batting in the box rather than fiberglass. About an inch of cotton batting on the back and side walls seemed to be about right. Be sure to leave the front baffle undamped.  If the midrange still seems too dead cover only half of the surface area of the interior of the box and alternate the coverage of the walls. Any wall directly across from another wall should have half its surface covered with batting and the other half should be bare.
Scotty
Title: Re: Econowave Speakers
Post by: _Scotty_ on April 26, 2012, 01:38:24 PM
Rollo, thanks for the kind words, it's not broke so I'm not fixing it, yet.  :lol:
Scotty
Title: Re: Econowave Speakers
Post by: richidoo on April 26, 2012, 02:36:23 PM
OK, thanks Scotty. I'll see if I can measure outdoors. I agree it is like a loudness button all the time. 

Another thing to consider is that I've never measured the box without the low pass filter. If the driver does have too high inductance or if the crossover design is wrong, then I could be chasing my tail for no reason.

Mike, I did switch over to WBCD after you reminded me earlier in this thread, and I like it! It gives similar results as WinISD for the box. I agree it is more powerful. I can't get the excel charts to work, even with Jeff's help, but the box calculations work. I used that for everything since the first design. I just grabbed WinISD today because I can see and post the FR charts. And the sim results are similar.

Thanks guys! I'll let you know how it works without the crossover and with longer ports, etc.
Title: Re: Econowave Speakers
Post by: richidoo on April 29, 2012, 01:12:02 PM
I have two 11.5" ports in each speaker. Slightly less boomy in the mid bass, but even more punchy in the lowest freqs. Slightly less loud in the upper bass, but still too loud in the lower freqs. Bass speed is slow and muffled, stretching up into the midrange. The speaker sounds less of a whole, more confused now than before. I assume the ports are too long and things could be improved by shortening them. But the result will be something between what it sounds like at 6" and what it sounds like at 12", I don't like either. I don't like the exaggerated physical punch of the very low freqs, and I don't like the smearing of the group delay.

What about other variables like smaller diameter ports? Is there a sound quality difference between a narrower port and a wider port both tuned to the same freq?  Most pro audio PA monitors with 12" woofer have smaller diameter ports.

The DATS (Dayton Audio Test System) arrived so I can make impedance and T/S tests. Maybe my driver measurements are at fault. It will be interesting to see if its measurements vary much from the previous generation unit, WT3.
Title: Re: Econowave Speakers
Post by: Face on April 29, 2012, 01:28:28 PM
Where are you crossing over?

Please don't tell me you're listening to the woofer by itself...  :-P
Title: Re: Econowave Speakers
Post by: richidoo on April 29, 2012, 02:41:35 PM
Tweeters are on!  :thumb:

Nominally the xo is 1500Hz:
(http://techtalk.parts-express.com/attachment.php?attachmentid=8028&stc=1&d=1270676492)
Title: Re: Econowave Speakers
Post by: richidoo on May 01, 2012, 08:41:22 PM
I removed the foam fill, so back to ~120 liters. FG is back in, and the 12" ports are installed for now. I intend to seal the box, but I'll listen to it for a bit first with the bigger box.

I found an online calculator based on Vance Dickason's Loudspeaker Cookbook recipe. It gives very different values than the 2 simulators I tried before that use the classic formulas. Larger box, larger diameter but shallower port. I'm not planning on building these at this point, but interesting alternate view.
Title: Re: Econowave Speakers
Post by: richidoo on May 06, 2012, 07:44:11 AM
I have found at least 4 different formulas for determining the optimum volume and port geometry for a max flat vented box. The volumes range from 136 to 194 liters for the same T/S input. Science?  :?

WinISD beta 0.44  
Jeff Bagby   http://audio.claub.net/software/jbabgy/WBCD.html (http://audio.claub.net/software/jbabgy/WBCD.html)  
Vance Dickasen http://www.mh-audio.nl/BassReflexLoudspeaker.asp (http://www.mh-audio.nl/BassReflexLoudspeaker.asp)
Don Keele http://diyaudiocorner.tripod.com/formula.htm (http://diyaudiocorner.tripod.com/formula.htm)

I am thinking the box needs to be significantly larger for these drivers to reach their optimal max flat alignment. Bigger is better just like sealed.
Title: Re: Econowave Speakers
Post by: richidoo on May 10, 2012, 06:22:47 PM
I have the ports sealed up now with temporary plugs. To me this sounds so much better than ports. I'd like a little more down low, but not much.

Floor bounce occurs at 468Hz, according to this online calc
http://mehlau.net/audio/floorbounce/ (http://mehlau.net/audio/floorbounce/)


Title: Re: Econowave Speakers
Post by: rollo on May 17, 2012, 08:45:11 AM
   Rich , could you use a method of reflecting the floor bounce away from your lisetening position ? Back in the day my buddy used mylar panels on the floor to redirect the beaming tweeter  to diffusors on the side walls from his B&W 802s.
   

charles
Title: Re: Econowave Speakers
Post by: richidoo on May 18, 2012, 10:21:14 AM
I don't know Charles, but it sounds like a good idea, but low WAF since it will need to be hefty enough to reflect at 400Hz, and angled differently than the floor it rests on. Bachelor fix. :)

Face, I need some PCD help. I can't see any FR in PCD. I see phase, filters, impedance plotted in the main "system response" graph where the FR should be, but I see no frequency response. Nor do I see FR in the driver specific FR/filter graphs down lower. I have the buttons pressed on the graph to show raw driver SPL and driver response, and I have all the other data entered, like offsets and such. Screen shot attached.

I measured FR and phase with HOLMImpulse and exported in several ways (linear, log, various delimiters) but no fix. I have read the FRD consortium notes on how to make FRD file. The frd file is importing into PCD and data is displayed in the SPL sheet, and the data looks OK. Any ideas?
Thanks
Rich
Title: Re: Econowave Speakers
Post by: Face on May 18, 2012, 10:58:32 AM
I've only used Arta and the Omni mic and never had that issue.  But, the same thing happened to me when I tried to import measurements taken from Jon Marsh(HT Guide).  I don't remember off the top of my head what he uses, but it's Mac based. 

Do the samples included with the software work? 
Title: Re: Econowave Speakers
Post by: richidoo on May 18, 2012, 11:15:27 AM
Good idea, thanks Mike. I hadn't tried the samples. Yes, the sample frd's work.

Comparing the sample frd to mine I see that my amplitudes are negative values (relative to 0dBFS) not in positive absolute values like the sample.frd.   I have ARTA so I'll try that if I can't convert the HOLM files to positive amp. values.   
Title: Re: Econowave Speakers
Post by: richidoo on May 24, 2012, 03:19:54 PM
Been messing around with the PCD crossover simulator, it is fun! Learning a lot about what parts do what. Very informative exercise. 

I discovered that there is a null at the crossover freq with the Econowave Delite crossovers I am using. Must be different polarity conventions with the different brand drivers. I have them wired in reverse according to the colors on the driver terminals, but measurements don't lie, one of them is wrong. I'll figure that out later.

But in viewing the measurement made with HolmImpulse, versus the simulation of the drivers and crossover made with Jeff Bagby's Passive Crossover Designer there is great correlation!

Note the reversed measurement and sim are very alike, the null is the same shape at the same freq.

The hopeful thing in all this is how nice the simulated speaker with the correct polarity is - nice and flat. I will use a battery to determine the reverse polarity of woofer, and the correct for the tweeters tonight and post a measurement tomorrow. I have two baseball games to attend tonite. My oldest is pitching! :D 

No wonder the sound has been bugging the hell out of me. I wonder if the Eminence drivers were this way also. Time will tell

Title: Re: Econowave Speakers
Post by: richidoo on May 25, 2012, 11:05:49 AM
I used a D cell battery to determine that the AE red post is positive. Same for the Eminence drivers. So I wired the AE in reverse per LR2 requirement. However, the Radian compression driver is in phase with the woofer when it is wired opposite of what the colors would indicate. Black post is positive.

I have read about this being typical of CDs, done to make field replacement repairs less confusion to the techs. The mfgs know that most applications are LR2, and most will reverse the tweeter so they can keep the positive thump from correct polarity in the bass. So they help the techs avoid crossover null by anticipating their ignorance and coloring the posts opposite of the reality.

So, now with the polarity fixed, the measurement shows well behaved crossover region,(red) compared to reversed polarity (blue.) This recorded with sine sweep from 1m at height between driver centers.  I have been listening to this crossover null since I built these things. I forgot about the child-psychology polarity fake out thing.

I'll tune the tweeter level flat with the measurement equipment, then fix and tune the other one, and try some listening! Just in time for the weekend.
Title: Re: Econowave Speakers
Post by: richidoo on May 25, 2012, 12:50:24 PM
Wow, what a huge improvement fixing the polarity has made, as expected from looking at the change to the FR. Now I understand the excitement over the econowave concept. Honestly I was starting to scratch my head for a while, and got frustrated that I couldn't get any traction with this project, but it was my own mistake. This explains my comments previously about midrange energy lacking. Now it is engaging and easy to drift into the music, while bringing lots of delicious detail in the lower mids and bass. 

Still to come are replacing the adjustable tweeter LPad with fixed resistors to allow contouring the treble response, building an adjustable line level baffle step correction box to add some bass boost, removing more FG from the box to loosen up the woofer a little more, and applying damping material to the outer surface of the plastic horn.
Title: Re: Econowave Speakers
Post by: richidoo on May 25, 2012, 03:50:52 PM
The bump at 450Hz is too much. I can't figure out what is causing it. Floor bounce dip should be ~470, but it is peaking there instead.  :?  And the bassiness is audible even when walking around. So the floor bounce is probably helping some.

Could be the woofer is rolling off too early with the Zilch crossover, making a bump that should stay flat at that level. I'll have to do some sweeps with driver only and adding crossover parts to figure it out.
Title: Re: Econowave Speakers
Post by: Face on May 25, 2012, 06:32:11 PM
Is it still there if you measure it nearfield? 
Title: Re: Econowave Speakers
Post by: richidoo on May 26, 2012, 09:51:55 AM
I'm gonna check that, and also at listening position 3m, and maybe outside too. I'll post.

The box is 120l, way more than the AE driver needs for Qtc .5, so it is overdamped. Can that cause a bump like that?

I think the bump is too low freq to be caused by internal reflections?
Title: Re: Econowave Speakers
Post by: richidoo on May 26, 2012, 12:50:03 PM
Looks like room reflections.  

Measured with no xo filter, amp to driver.
Red is 1" from phase plug, blue is 1meter, green is listening position 3m.  In the 1st pic all are gated 100Hz/3.5m   In the 2nd pic, each is gated to it's actual distance from the driver.

I didn't suspect room, because it sounds similar standing in different places in the room. I'll try moving it around, and outdoor measurement.
Title: Re: Econowave Speakers
Post by: richidoo on May 26, 2012, 01:04:49 PM
Here is the sweep at 3m listening spot, gated to 3m. Green is raw driver, red is with xo filter engaged.
Title: Re: Econowave Speakers
Post by: richidoo on May 26, 2012, 01:37:18 PM
Here's a shot of the whole speaker, in the same location. With the tweeter turned up flat with the woofer's flat zone there is a big dip at the crossover, caused by too sooon rolloff of the woofer. Tuning the level of the tweeter by ear to match that dip would explain the woofer bump. This is the basic problem I had before when I suspected the Eminence woofer inductance to be the cause of the rolloff, but it turned out to be in spec. The AE is lowest inductance of any woofer, but still rolling off too soon.

I will verify the inductance of the Erse super Q 3.3 woofer filter coil that I am using now. Geddes uses 2mH in Abbey, this is similar design.
Title: Re: Econowave Speakers
Post by: richidoo on May 26, 2012, 01:57:10 PM
Replaced the 3mH coil with 1mH aircore, no more dip. But there is too much overlap @1500-2k. The 1mH coil is too small, allowing the woofer to play too high, combining with tweeter output to be too loud. I guess 2mH is worth a try.
Title: Re: Econowave Speakers
Post by: richidoo on May 26, 2012, 02:08:30 PM
This is gonna piss off 2two, er I mean Evan who hates the same thread hogging up the whole forum... hehe

Blue is 2mH on the woofer, two 1mH in series. Red is 1mH. 2mH  the 1.5-2k peak at xo. 1/6 octave smoothing.

Now for the peak at 650 and dip at 1200. Hopefully just acoustic. although I'm not so sure about the 1200.
Title: Re: Econowave Speakers
Post by: richidoo on May 26, 2012, 02:23:57 PM
Face, how do you recommend to measure drivers for importing into PCD? Should I do it in room where the speakers will play, or should I do it outside up high to eliminate as many reflections as possible?   Tom Danley says measure without reflections, then apply filters. What do you do?
Title: Re: Econowave Speakers
Post by: richidoo on May 26, 2012, 02:59:27 PM
1st pic is Moving the speakers around on floor. Blue is original spot. Red is 1 foot forward. Green is 2 feet backward. Doesn't make it go away.

2nd pic is height. Green is on floor. Red is lifting it up 3.75" Makes it worse, but could be on track if it's a ceiling mode.

Ceiling is 9 or 10 feet. Fundamental of 9 feet is 63Hz. No way that big of a higher order harmonic mode at 650.

What do you think is causing the 650 bump?  It seems to be narrower with the 2mH coil than with the original 3mH coil.
Title: Re: Econowave Speakers
Post by: 2two on May 26, 2012, 03:30:53 PM
This is gonna piss off 2two, er I mean Evan who hates the same thread hogging up the whole forum... hehe

Blue is 2mH on the woofer, two 1mH in series. Red is 1mH. 2mH  the 1.5-2k peak at xo. 1/6 octave smoothing.

Now for the peak at 650 and dip at 1200. Hopefully just acoustic. although I'm not so sure about the 1200.


Not that I know Evan but after reading about what went on I think he was more upset about the worthless posts . IMO
Title: Re: Econowave Speakers
Post by: richidoo on May 26, 2012, 03:45:17 PM
Yes, (and thanks)
Title: Re: Econowave Speakers
Post by: Face on May 26, 2012, 03:57:06 PM
Face, how do you recommend to measure drivers for importing into PCD? Should I do it in room where the speakers will play, or should I do it outside up high to eliminate as many reflections as possible?   Tom Danley says measure without reflections, then apply filters. What do you do?
For PCD, I measure at 1m with bass traps all around, eliminating all reflections.
Title: Re: Econowave Speakers
Post by: mgalusha on May 26, 2012, 04:00:26 PM
Face, how do you recommend to measure drivers for importing into PCD? Should I do it in room where the speakers will play, or should I do it outside up high to eliminate as many reflections as possible?   Tom Danley says measure without reflections, then apply filters. What do you do?

Rich,

Not sure it will work any better, but Wayne Parham suggests laying the speaker on it's back and positioning the mic about a meter above it. Doing so outside is of course better. At least that should help sort out if the bump is the speaker or the room interaction. 650Hz is 1' 9" according to the real traps calculator.

mike

Edit: Wayne's measuring suggestions: http://audioroundtable.com/forum/index.php?t=msg&&th=12291&goto=72746#msg_72746 (http://audioroundtable.com/forum/index.php?t=msg&&th=12291&goto=72746#msg_72746)
Title: Re: Econowave Speakers
Post by: richidoo on May 26, 2012, 04:03:13 PM
OK, thanks Face. I'll redo the measurements without echos, and with correct polarity.

The low mid overkill is gone, tweeter is cranked up where it should be so the overall sensitivity is better. The speaker sounds better overall, but I only have parts to mod the one speaker so I'm listening to one. I don't hear the 650 peak and 1200 dip specifically but they're still there.
Title: Re: Econowave Speakers
Post by: richidoo on May 26, 2012, 04:19:08 PM
mgalusha, thanks for the tip to lay it on back. With controlled directivity it should work great. I had my son talked into helping me hoist it 4 feet up onto a scaffold, so he will be relieved to hear an easier solution. :)

650Hz = 21"... Hmmmm.... the box interior height dimension is 40.5", but there's no bump at the fundamental 335Hz. Could just be a coincidence.  I think the big horn and big AE driver as obstacles inside the box would diffuse any vertical reflections.
Title: Re: Econowave Speakers
Post by: richidoo on May 26, 2012, 05:41:07 PM
When measuring the drivers, should I put the mic halfway between their center heights? That is also my listening ear height. Then don't move the mic or test signal gain between woofer and tweeter measurements, right?

Or do you measure each driver on its own axis? Seems like you would lose the phase relationship.
Thanks
Title: Re: Econowave Speakers
Post by: Face on May 26, 2012, 07:03:59 PM
Even with your listening height, at 1 meter tweeter height should be fine.  But with your C-C distance and being a CD type speaker, 1m may be too close.  Your best bet will be outside and further away. 
Title: Re: Econowave Speakers
Post by: richidoo on May 30, 2012, 05:32:13 PM
It's been raining from TS Beryl last few days, so I haven't been able to measure outside yet. Tomorrow should be OK.

I am noticing the huge difference in midrange clarity gained by changing the woofer coils. Not only the value changed, from 3mH to 2mH (two 1mH coils in series,) but also the type of coil - the original was 3mH SuperQ iron core. The replacement 2mH are air cores. The midrange muck that I attributed to too much box stuffing is all gone, and I didn't change the stuffing.  It could be from filling in the missing midrange frequencies, and also from removing the magnetic hysteresis of the core, or both. 

I ordered some 2mH and .5mH air core Erse 14ga coils today from PE so I can play around with the values to zero in on what I like. I'll order some pad resistors and parts for BSC from Mouser tomorrow. btw Did anyone see the Mouser Electronics sponsored car in the Indy500? Tony Kanaan came in 3rd in the Mouser car! He might have won if not for last lap accident.

The combination of Radian and AE drivers is great. With the midrange flattened now the intensity and detail is really strong. Still more refinement needed, but there is incredible potential, considering the better horn coming and more crossover tweaks.

Using PCD is teaching me what the various crossover parts do, how they react to value changes. I'm hoping it will be easier to make tweaks by ear. Something I always thought was magic before. You know you're ignorant when something looks like magic.
Title: Re: Econowave Speakers
Post by: Face on May 30, 2012, 05:42:06 PM
I wouldn't use a Super Q higher than the woofer of a 3 way...or any non-air core for that matter.   
Title: Re: Econowave Speakers
Post by: richidoo on May 30, 2012, 05:48:24 PM
Thanks Mike. I agree, now that I've heard it. Zilch spec'ed cheapest iron cores for the ewave.
Title: Re: Econowave Speakers
Post by: richidoo on May 31, 2012, 01:58:49 PM
I spent a couple hours outside in the hot sun with the bugs getting some measurements. Measurements are much flatter than inside, plus the mic and gain is same for Woofer and tweeter, and the phases are correct (I think) so sim should be easier and more accurate. The AE woofer had some FR anomolies when playing MLS signal lying down on back. It was fine playing on horizontal axis as intended.

I'll post some measurements soon.
Title: Re: Econowave Speakers
Post by: richidoo on June 01, 2012, 08:10:26 PM
I got the smaller air cores on both sides now. Do coils need to break in? Sounded a little tight at first. Opening now after a couple hours. I got a couple sizes that will allow fine tuning. I'll need to measure to see the changes.

With the iron cores gone, the bass is much cleaner, the whole speaker sounds much better, and plays louder. The iron cores seemed to really suck out the life and the volume.

So now, of course, with cleaner bass I can hear new LF flaws.  :x :)   The bass seems slightly resonant, chesty on alto girls and guitar low notes, etc. The box is sized for Q .57 with the Eminence Deltalite 2512, and it's way too big for this AE TD12X driver.  

EPB of this driver is 110. Probably shouldn't be sealed anyway. But that wouldn't make it too warm in the mid bass.

The simulated AE TD12X needs 30 liters for Q .7, 50 liters for Q .57,  75 liters for Q.5.   The box is currently at 120 liters, which spells Q .43   :shock:  What is the sonic penalty of too large sealed box? I've searched hi and lo for the answer.  Grant me this wisdom, mighty Oracle.

Also, there is minimal fill inside the sealed box now. Usually sealed boxes will have more fill, sometimes even stuffed full. I don't need more volume, so I didn't bother filling it with fluff. But maybe more is necessary to damp the driver better?

More stuffing and smaller box?
Thanks :D
Title: Re: Econowave Speakers
Post by: richidoo on June 01, 2012, 08:24:57 PM
Simulations of 30, 50 and 75 liters with AE TD12X.
Title: Re: Econowave Speakers
Post by: Face on June 01, 2012, 08:25:08 PM
I got the smaller air cores on both sides now. Do coils need to break in? Sounded a little tight at first. Opening now after a couple hours. I got a couple sizes that will allow fine tuning. I'll need to measure to see the changes.

With the iron cores gone, the bass is much cleaner, the whole speaker sounds much better, and plays louder. The iron cores seemed to really suck out the life and the volume.

So now, of course, with cleaner bass I can hear new LF flaws.  :x :)   The bass seems slightly resonant, chesty on alto girls and guitar low notes, etc. The box is sized for Q .57 with the Eminence Deltalite 2512, and it's way too big for this AE TD12X driver.  

EPB of this driver is 110. Probably shouldn't be sealed anyway. But that wouldn't make it too warm in the mid bass.

The simulated AE TD12X needs 30 liters for Q .7, 50 liters for Q .57,  75 liters for Q.5.   The box is currently at 120 liters, which spells Q .43   :shock:  What is the sonic penalty of too large sealed box? I've searched hi and lo for the answer.  Grant me this wisdom, mighty Oracle.

Also, there is minimal fill inside the sealed box now. Usually sealed boxes will have more fill, sometimes even stuffed full. I don't need more volume, so I didn't bother filling it with fluff. But maybe more is necessary to damp the driver better?

More stuffing and smaller box?
Thanks :D
How well braced is the box?  

Want to make them smaller?  Do you have any extra bricks in your yard?  Sand maybe?  :D
Title: Re: Econowave Speakers
Post by: richidoo on June 01, 2012, 08:29:11 PM
Thanks Mike. They are well braced. I do have some extra pavers that I could jam in there. But I could not kill off 50 liters with bricks. I can fashion a removable divider board that cuts it down.

Do you think the low Q could be the cause?

I don't gain much more extension below Q.5 anyway.
Title: Re: Econowave Speakers
Post by: Face on June 02, 2012, 06:04:03 AM
Thanks Mike. They are well braced. I do have some extra pavers that I could jam in there. But I could not kill off 50 liters with bricks. I can fashion a removable divider board that cuts it down.

Do you think the low Q could be the cause?
Yes, it's possible.  A new cab or divider would be your best bet. 
Title: Re: Econowave Speakers
Post by: richidoo on June 02, 2012, 11:45:58 AM
I'll get started on that. Thanks

While measuring to set the tweeter level, I was seeing that 8.2kHz null in the FR. I saw it outside too, even facing up. I suspected it is the horn reflections, and this measurement confirms that. Taken with mic at the throat of the horn, 1/8" from the CD screen.

Radian says the 475 biding posts are marked correctly, red is positive. So ignore previous rant.
Title: Re: Econowave Speakers
Post by: Face on June 02, 2012, 06:20:10 PM
Radian says the 475 biding posts are marked correctly, red is positive. So ignore previous rant.
I believe JBL marks them incorrectly for those who have no idea what they're doing.  :D
Title: Re: Econowave Speakers
Post by: mgalusha on June 02, 2012, 07:35:23 PM
I believe JBL marks them incorrectly for those who have no idea what they're doing.  :D

Yes indeed, at least on the JBL woofers I have, thankfully they note it in the data sheets.
Title: Re: Econowave Speakers
Post by: richidoo on June 04, 2012, 11:34:36 AM
I installed a removable floor panel just below the woofer, reducing internal volume by almost half. This makes net volume (Vb) of 65 liters, which makes Qtc = .52. Perfect!   The chesty sound is improved. Bass is much punchier and tighter now, no loss in bass extension, actually sounds like a little more extension. Speaker sounds a little bass heavy now, so back to the crossover.

The FR bump at 600Hz is still there. I think the 2mH woofer coil might be still too big. I will reduce it to 1.5 to see if the hole just above the bump fills in to meet the tweeter more smoothly. Then I can turn up the tweeter to balance out the bass.

The resistors arrived from Mouser today, so after I choose the woofer coil, I will start work to replace the adjustable LPad with a single fixed pad. I plan to tilt the tweeter down a bit at the top, which the LPad did not allow but discreet resistors will. When I turn up the tweeter to match the woofer, then the highs are too loud. When I turn down the tweeter for music listening, then the midrange hole returns.
Title: Re: Econowave Speakers
Post by: richidoo on June 05, 2012, 02:04:47 PM
I reduced the woofer coil, but that did not fix the bump and dip at 600-800. The smaller inductance sounds too midrangy.

I looked at the measurements I made outside last week. Red is woofer only, no filter, with driver axis pointing vertical with speaker lying flat on the ground, outside, mic 1meter. Blue is speaker standing up as normal, outside, mic 1m. Box was sealed 120l, lined with 2" pink FG.  Test signal MSSLA

What are those bumps? Do I need more stuffing to damp the woofer? 
Title: Re: Econowave Speakers
Post by: Face on June 05, 2012, 04:49:32 PM
What's going on at 600 looks similar to this one(TD-15x): http://5e8772ee-a-62cb3a1a-s-sites.googlegroups.com/site/drivervault/driver-measurements/15/ae-speakers-td15x/frequency-response/SPL_nearfield.PNG?attachauth=ANoY7cpjuk9H7xJw5IqYu_giIuhtyRe-eDXoJoSMgje8FqfW1mT-S82uB2alWcJlljj-Osi2vTsWcoKogoHH4quHg3T7t2OQ8VutHyh-y0cXNtpwIUYsv63KiUym0aWZTF2qRGewAu0NN6AiMMmbUuAnFsiVSREnso0s8IOX2ud65O27aeK01xVPe79U7KMSJTSCEMq-SoL0Xw6MXz4vzMI1TWmzVj79s9uWK0NkTIN3z-a6OLKSXubbgKJvmzOuu5YKzNxy0k8Wia1s6GzikfDckjHM8NskX23LGCosIgeXnfz-2Iv-DLI%3D&attredirects=0 (http://5e8772ee-a-62cb3a1a-s-sites.googlegroups.com/site/drivervault/driver-measurements/15/ae-speakers-td15x/frequency-response/SPL_nearfield.PNG?attachauth=ANoY7cpjuk9H7xJw5IqYu_giIuhtyRe-eDXoJoSMgje8FqfW1mT-S82uB2alWcJlljj-Osi2vTsWcoKogoHH4quHg3T7t2OQ8VutHyh-y0cXNtpwIUYsv63KiUym0aWZTF2qRGewAu0NN6AiMMmbUuAnFsiVSREnso0s8IOX2ud65O27aeK01xVPe79U7KMSJTSCEMq-SoL0Xw6MXz4vzMI1TWmzVj79s9uWK0NkTIN3z-a6OLKSXubbgKJvmzOuu5YKzNxy0k8Wia1s6GzikfDckjHM8NskX23LGCosIgeXnfz-2Iv-DLI%3D&attredirects=0)
Source: http://sites.google.com/site/drivervault/driver-measurements/15/ae-speakers-td15x/frequency-response (http://sites.google.com/site/drivervault/driver-measurements/15/ae-speakers-td15x/frequency-response)

There's a chance it's a surround resonance...  FYI, when measuring nearfield, measure a couple inches from the phase plug, too close and you'll get wonky results too.

But judging by this post: http://www.audionervosa.com/index.php?topic=3697.msg52556#msg52556 (http://www.audionervosa.com/index.php?topic=3697.msg52556#msg52556)  I'd say it's probably a combination of diffraction and your room. 

Have you modeled your cabinet/woofer with The Edge: http://www.tolvan.com/edge/ (http://www.tolvan.com/edge/) 

Without going through all 16 pages again, any distortion plots with and without an x-over in place? 
Title: Re: Econowave Speakers
Post by: richidoo on June 05, 2012, 06:07:34 PM
Thanks Mike! The dip at 700 is always there, inside or outside, at any mic distance, so it is likely a driver thing. Fortunately a null and somewhat narrow.  But I agree with you that the ~600 peak is probably acoustic because it changes. I'll get around to improving the placement after I get closer on the crossover tweaks.

Edge is cool, thanks. Attached is the sim. Not related to the woofer anomalies.

I also tried stuffing the boxes with acoustistuff. It just killed transient speed, chesty was still there, worse maybe. How could it be worse - maybe it was phase, so I wondered if chestiness could be related to tweeter?
 
So I changed the 20ga tweeter coil to 14ga, very nice improvement, much more detail and dynamics! Seems like the chestiness is also gone. Could that <500 mud have been coming from the horn?  :shock:

I haven't done any distortions yet. Holmimpulse is supposed to do it but I haven't figured out why it's not appearing.
Title: Re: Econowave Speakers
Post by: richidoo on June 06, 2012, 09:04:08 AM
Spent the morning replacing the Zilch adjustable tweeter pad with fixed. After about a dozen changes on each speaker it is getting very close now. 17dB attenuation on the CD at Fxo, then a little more rolloff as it goes higher. Pad is 12ohms series, 2ohms parallel.

The QSC horn does beam a little bit. So I had to bring down that beam. The best imaging is when horns are toed in a little, so the sweet spot is a little less treble than I would like. But it is easy to get used to less treble, and better than having too much.

The plastic horn needs damping.  

I also put the driver polarities to the way they should be, reversed and it worked fine. When I was using the 3mH coil there was an issue with that. With 2mH woofer coil I don't have a nice clean null at Fxo like it should when they are not reversed. I don't know how to tune xo to get that null. I think changing the original woofer coil screwed up the phasing at crossover. I have some ideas to work on that. Still need to try LCR on the tweeter.

Now I will work on room placement for the speakers to flatten the bumps in the bass. I'd like to pull 3dB out of 400-600Hz bump. Might have to notch that we'll see what the room does.

Edit: Oh, I forgot to mention, it sounds good! I've heard commercial speakers that cost more and sound worse, so I am going inthe right direction, slowly.
Title: Re: Econowave Speakers
Post by: BobM on June 06, 2012, 09:25:32 AM
Rich - when do you work to support your family? I keep reading daily exploits of cabinet tweaking during the day. I have to assume you work at home or are independently wealthy (can you please adopt my youngest daughter?).

It's good to read about your discoveries and progress. Keep up the good work.
Title: Re: Econowave Speakers
Post by: richidoo on June 06, 2012, 10:04:57 AM
Thanks Bob!  Independent, yes, wealthy, not yet...  

Edited:  Too much personal info posted in a rare, paranoia-free moment .  :D
Title: Re: Econowave Speakers
Post by: Tytte71 on June 06, 2012, 03:17:32 PM
Hi Rich! I haven't got the chance to read all the posts in your thread yet, but will do when I get the time. I love your project and look very much forward to follow its progress.
Now I have looked at the 700Hz null a bit and wonder if it's caused by cabinet reflections and not driver edge resonance. Please have a look at the impulse response. As you can see, there are some reflections identified at 60-80cm (corresponding to a distance of 30-40cm). When gating to eliminate the reflections, the nulls are gone. Just a thought :)


Title: Re: Econowave Speakers
Post by: richidoo on June 06, 2012, 04:14:51 PM
Welcome O!! Good to have you here.  :thumb:

Thanks for looking at my measurements. I understand the concept of impulse measurement, but I don't know how to intepret it, or how to properly use gating. There is so much to learn...

Now with a new fake floor installed in the box to reduce the Vb the interior vertical dimension is about 60cm, but when those measurements were taken, there was no reflective dimension between 60-80cm. I have enough acoustic damping installed to kill off an internal reflection that high.

If it is a surround resonance, would it show up in nearfield free air measurement?
Thanks!
Title: Re: Econowave Speakers
Post by: Tytte71 on June 07, 2012, 02:05:18 PM
Thanks Rich, it's my pleasure!

Since the woofer otherwise looks so fine it would be so incredibly nice to get rid of that midrange inconsistency. But that would off course depend on some further investigations.

I received two measurement files from you - one with the speaker standing and the other with the speaker laying with its back to the ground. Both measurements done outdoor and with both frequency response curves showing the same tendency of the null at ~750Hz. The two independent measurements should eliminate the ground as the sinner since the heigth from the driver's acoustic centre to the ground would be different in the two cases. Second, the measurements were done with the cabinets sealed, which eliminates any strong quarter wave pipe resonance from the port(s). And third, the measurements were taken without any filter which eliminates any misaligned or faulty filter.

The impulse starts with a high and sudden signal and quickly rings out with some minor ripple. This is perfectly normal.  But then... a strong signal suddenly occurs again after a "long delay". We read two successive and relatively strong pulses, starting at 64cm (~57 +~7cm) corresponding to a delay of 1.87ms. This late arrival is an indication of some kind of surrounding reflection and could not be caused by the driver itself (like i.e. the diaphragm can't suddenly break up after a while when the cone motion have stopped).

To see the impact of these late arrival pulses I gated the measurements to exclude their contribution to the summed frequency response. What happens is that the problem area around 750Hz flattens out. When gating the signal this way the accuracy in the lower frequencies is lowered and ripple in the mid/tweeter band is filtered (eliminating any sorrounding reflections creating the summed frequency response).
My preliminary conclusion is that we have two potential sources for the error ;
1.Something on/in the cabinet reflecting out the diaphragm and
2. Reflecting surroundings in the area where the measurements were taken.

Let's assume it is from the cabinet itself. Then it is reason to believe that the reflection comes from the inside. Length of first delay is approximately 64cm and divided by two should give a distance of 32cm to the reflective surface (180 degree phase shift occurs when a soundwave is reflected). What we also can see from the impulse response is that the late arriving pulses is attenuated compared to the first pulse. This could very well be due to the internal wall damping. Pulse No.2 arrives after some 76cm giving a distance to a reflective surface of 38cm. After pulse No.2 there is a period of repetitive smaller pulses like somehing rings out.
I am thinking these reflections could very well be caused by first reflections from the back wall and then internal standing wave modes within the cabinet.

If you have the possibility, then I will propose to take a uncut sheet of plywood (inifinite baffle) and mount the woofer to it. Remeasure and see if you still have the problem. If that's impossible then do a new measurement of the raw woofer at some 2m above ground.

I hope it could be worth it :)
Title: Re: Econowave Speakers
Post by: richidoo on June 07, 2012, 06:49:40 PM
Thanks Oystein for your explanations and ideas. 

I can't do infinite baffle test, but I can test the driver free air outside.

I can also measure with the cabinet stuffed solid with acoustic damping.

I don't notice the 750Hz null much, except on trumpet recordings that I've listened to for 35 years, then only if I concentrate and look for it. I do notice the warm midrange glow of the bump just below at 400-600. I'm hoping that's room related.

If interfering waves cancel with floor bounce, can they not also combine to make a peak at adjacent frequencies to the null?

One thing I am noticing is that the speakers sound really good out of the sweet spot, especially far away, owing to the good power response, and the pro-audio origins of the design (horn + woofer.)

The speakers seem to reveal flaws in recordings very well. I think some of the flaws are still in the speakers, but some stuff is obviously recording related. There are a lot of bad recordings out there! Maybe a good reason why tubes go well with horns.
Title: Re: Econowave Speakers
Post by: Carlman on June 07, 2012, 07:06:52 PM
There are a lot of bad recordings out there! Maybe a good reason why tubes go well with horns.

Maybe a good reason ANY setup likes a little glossing over/pleasing distortion/rosey-ness/etc... If your system is too revealing, you'll only be able to listen to well-recorded music.  There is a balance of what we think "natural" is.  It comes with some flaws with the details... something has to trick us into believing it is real.  When you can hear all the tricks in the studio, it's obvious we're trying to be tricked. ;)  Our brain refuses to allow us to love the music at that point.

Glad to know the speakers are getting to the point where you can discern this.. NOW is when the real art of voicing can happen. :) Cool!
Title: Re: Econowave Speakers
Post by: Tytte71 on June 08, 2012, 01:23:53 AM
I can't do infinite baffle test, but I can test the driver free air outside.

I can also measure with the cabinet stuffed solid with acoustic damping.

Measuring driver free air and then with cabinet stuffed would be interesting... Free air measurements to find if the null is gone and stuffed box to see if it is possible to find a workaround with your cabinets if internal reflections causes the bump.

I don't notice the 750Hz null much, except on trumpet recordings that I've listened to for 35 years, then only if I concentrate and look for it. I do notice the warm midrange glow of the bump just below at 400-600. I'm hoping that's room related.
I would recommend concentrating on the null first. Eliminating this might also eliminate or show irregularities that otherwise could fool us.

If interfering waves cancel with floor bounce, can they not also combine to make a peak at adjacent frequencies to the null?
Reflections within 0-20ms would add to our perceived frequency response. Bouncing waves will induce phase shifts and can sum up to a nasty result.

One thing I am noticing is that the speakers sound really good out of the sweet spot, especially far away, owing to the good power response, and the pro-audio origins of the design (horn + woofer.)

The speakers seem to reveal flaws in recordings very well. I think some of the flaws are still in the speakers, but some stuff is obviously recording related. There are a lot of bad recordings out there! Maybe a good reason why tubes go well with horns.
Glad to hear you are getting some good stuff from the boxes already :D
But, is there a distinct difference in sound balance in the mid/tweeter band when listening off-axis compared to on-axis?
Title: Re: Econowave Speakers
Post by: richidoo on June 08, 2012, 07:24:50 AM
I chase the worst problem first to stay motivated and make progress.

I have some sawhorses that are the perfect height to invert the speakers while maintaining same tweeter height. That will illuminate any floor bounce effect. I have always liked bass drivers to be elevated anyway, but not a practical mod for this speaker.
http://mehlau.net/audio/floorbounce/ (http://mehlau.net/audio/floorbounce/)
Floor bounce supposedly centered at 315Hz at current position.

Sounds is consistent off axis, best I ever had in this regard.
Title: Re: Econowave Speakers
Post by: Tytte71 on June 08, 2012, 09:53:53 AM
Those damn sound waves - why don't they just move in a straight line towards our ears :roll:

I see - raising the speakers! I would then detail my answer to theprevious question a bit.
If interfering waves cancel with floor bounce, can they not also combine to make a peak at adjacent frequencies to the null?
Nyes... Yes if the first reflection was the only thing causing the dip. No since I believe that we also see ringing, similar to resonance/standing waves.
Adjusting floor height/bounce to linearize the frequency response could make things look better but will not cure the time domain issues.

It would be nice to see you measurements when you have raised and turned the cabinets  :)
Title: Re: Econowave Speakers
Post by: richidoo on June 08, 2012, 10:39:18 AM
I'll need some teenage assistance to raise the boxes. With drivers they feel like 100#

Here is a graph of three close measurements.
Blue is mic 10" from the driver cone, off center halfway between phase plug and surround.

Green is mic 1/4" from surround, mic parallel to driver axis, front baffle thickness next to mic tip.

Red is mic 1/4" from driver cone halfway between phase plug and  surround.

All raw measurements, no gating at all. Signal after XO filter, horn playing, but mic is outside the directivity of the horn.

Looks to me like this dip is not room acoustic phenomena.

Stuffing the bird next
Title: Re: Econowave Speakers
Post by: richidoo on June 08, 2012, 10:54:59 AM
No change after stuffing the speaker tightly with poly fill. Mic position same as red plot above, 1/4" from mid radius of driver cone, see pic. Stuffed curve is purple.

HOLM.zip emailed so you can check the impulse. I can't figure how to zoom in like you did.

Outside free air is next.
Title: Re: Econowave Speakers
Post by: richidoo on June 11, 2012, 05:05:12 PM
In tribute to our esteemed visiting guest, Evan1, I refrained from posting about my speakers until it fell off the front page list. Now that he's gone...

The tweeter resonance is 600Hz, and could be causing the midrange bump at that freq. I have parts for a LCR damping filter which I will try tomorrow. Thanks to mgalusha for suggesting this at least a month ago...  :duh

Edit: Actually the bump is there with woofer only tests. But worth a try anyway to see what it does, if anything.

The dip at 700 on the AE woofer was seen in free air FR sweep, and corresponds with a small blip in the impedance curve, and is common with high Xmax drivers like this. The cloth accordion surround M version of this speaker is said by the mfg to have less surround resonance.
Title: Re: Econowave Speakers
Post by: Face on June 13, 2012, 10:37:11 AM
The dip at 700 on the AE woofer was seen in free air FR sweep, and corresponds with a small blip in the impedance curve, and is common with high Xmax drivers like this. The cloth accordion surround M version of this speaker is said by the mfg to have less surround resonance.
The M has higher efficiency, but a smaller x-max. 

It's all about trade offs.  ;)

I have 4 TD-10M's here that I'm waiting to do something with.  Maybe I'll pair them with some SEOS 12's.
Title: Re: Econowave Speakers
Post by: richidoo on June 13, 2012, 11:13:22 AM
I have 4 TD-10M's here that I'm waiting to do something with.  Maybe I'll pair them with some SEOS 12's.

Sweet!  :drool:
Title: Re: Econowave Speakers
Post by: richidoo on July 09, 2012, 02:35:20 PM
SEOS-12s horns in the house!

And so with the removal of the QSC horns from this project, there is nothing left of Zilch's Econowave Deluxe but the inspiration.

So I'll start a new thread for future developments.
Title: Re: Econowave Speakers
Post by: Face on November 09, 2012, 06:43:30 PM
The dip at 700 on the AE woofer was seen in free air FR sweep, and corresponds with a small blip in the impedance curve, and is common with high Xmax drivers like this. The cloth accordion surround M version of this speaker is said by the mfg to have less surround resonance.
The M has higher efficiency, but a smaller x-max.  

It's all about trade offs.  ;)

I have 4 TD-10M's here that I'm waiting to do something with.  Maybe I'll pair them with some SEOS 12's.
Slow work takes time...

(http://i.imgur.com/FOTsh.jpg)

Aside from the finish, the center is done.  Glue is drying on the first main tower as we speak.  Hopefully both are done in a week or so.  
Title: Re: Econowave Speakers
Post by: richidoo on November 10, 2012, 06:35:36 AM
Looks nice Mike! The two separate racks work out great, huh? Are you gonna paint it RED or black?
Title: Re: Econowave Speakers
Post by: Face on November 10, 2012, 06:46:56 AM
The TV height worked out within an inch too. 

Going with black this time around.  Not sure what finish yet though.