Author Topic: Econowave Speakers  (Read 96284 times)

Offline hometheaterdoc

  • Obsessively Audiophilic
  • ****
  • Posts: 667
Re: Econowave Speakers
« Reply #75 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...

Shane Sangster
Used to be Night & Day Audio.......

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Econowave Speakers
« Reply #76 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. 

Offline Carlman

  • Audio Neurotic
  • *****
  • Posts: 3037
Re: Econowave Speakers
« Reply #77 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
I really enjoy listening to music.

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Econowave Speakers
« Reply #78 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.

Offline BobM

  • Audio Neurotic
  • *****
  • Posts: 3318
Re: Econowave Speakers
« Reply #79 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.
Laugh and the world laughs with you. Cry and you'll have to blow your nose.

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Econowave Speakers
« Reply #80 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.

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Econowave Speakers
« Reply #81 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.

Offline hometheaterdoc

  • Obsessively Audiophilic
  • ****
  • Posts: 667
Re: Econowave Speakers
« Reply #82 on: March 21, 2012, 09:03:48 PM »
woohoo!!  that sounds very encouraging, Rich!  Now I definitely can't wait to hear them :)
Shane Sangster
Used to be Night & Day Audio.......

Offline BobM

  • Audio Neurotic
  • *****
  • Posts: 3318
Re: Econowave Speakers
« Reply #83 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.
Laugh and the world laughs with you. Cry and you'll have to blow your nose.

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Econowave Speakers
« Reply #84 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.

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.

Offline Inscrutable

  • Certifiable
  • ***
  • Posts: 147
Re: Econowave Speakers
« Reply #85 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:

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Econowave Speakers
« Reply #86 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.

Offline hometheaterdoc

  • Obsessively Audiophilic
  • ****
  • Posts: 667
Re: Econowave Speakers
« Reply #87 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....

Shane Sangster
Used to be Night & Day Audio.......

Offline richidoo

  • Out Of My Speaker Cabinet
  • ******
  • Posts: 11144
Re: Econowave Speakers
« Reply #88 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.

Offline Inscrutable

  • Certifiable
  • ***
  • Posts: 147
Re: Econowave Speakers
« Reply #89 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.  :?