Author Topic: Econowave Speakers  (Read 96751 times)

Offline hometheaterdoc

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Re: Econowave Speakers
« Reply #105 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 :)...
« Last Edit: March 27, 2012, 08:56:41 PM by hometheaterdoc »
Shane Sangster
Used to be Night & Day Audio.......

mgalusha

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Re: Econowave Speakers
« Reply #106 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.


Offline richidoo

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Re: Econowave Speakers
« Reply #107 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:
« Last Edit: March 27, 2012, 08:19:12 PM by richidoo »

Offline hometheaterdoc

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Re: Econowave Speakers
« Reply #108 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 :)
« Last Edit: March 27, 2012, 09:04:51 PM by hometheaterdoc »
Shane Sangster
Used to be Night & Day Audio.......

Offline richidoo

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Re: Econowave Speakers
« Reply #109 on: March 27, 2012, 09:34:24 PM »
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.

Offline mdconnelly

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Re: Econowave Speakers
« Reply #110 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!


djdube525

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Re: Econowave Speakers
« Reply #111 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.

 :rofl:

Offline richidoo

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Re: Econowave Speakers
« Reply #112 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
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:

Offline richidoo

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Re: Econowave Speakers
« Reply #113 on: March 28, 2012, 07:03:41 PM »
See attached chart of T/S specs on 4 samples.

At least they are consistent.  :D
« Last Edit: March 28, 2012, 07:44:46 PM by richidoo »

Offline hometheaterdoc

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Re: Econowave Speakers
« Reply #114 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!
Shane Sangster
Used to be Night & Day Audio.......

Offline richidoo

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Re: Econowave Speakers
« Reply #115 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.

Offline hometheaterdoc

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Re: Econowave Speakers
« Reply #116 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:
Shane Sangster
Used to be Night & Day Audio.......

Offline richidoo

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Re: Econowave Speakers
« Reply #117 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.
« Last Edit: March 28, 2012, 10:18:27 PM by richidoo »

Offline _Scotty_

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Re: Econowave Speakers
« Reply #118 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#
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

Offline richidoo

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Re: Econowave Speakers
« Reply #119 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