Zilch's AK Design Collaborative - Econowave Speaker

[skywave-rider]

More 123A-1 Nearfield in KDTs

JBL 123A-1s in PE KDTrap boxes with baffles moved forward flush and woofers mounted behind baffles; #1 and #2.

Compare to Zilch's nearfield:
http://www.audiokarma.org/forums/attachment.php?attachmentid=188413&stc=1&d=1262929405

The tab thing almost works:
http://www.audiokarma.org/forums/attachment.php?attachmentid=188413&stc=1&d=1262929405
http://www.audiokarma.org/forums/attachment.php?attachmentid=188521&d=1262996258

Is my LF peak about 10Hz lower?
Note: QSC not mounted in box, sitting on top; these are bass bins.

 

[Zilch]

Is my LF peak about 10Hz lower?
Note: QSC not mounted in box, sitting on top; these are bass bins.

Your box volume is larger, so Fc is slightly lower. We can compare impedance measurements to substantiate that, if you want. :yes:

I also had too much LF comp in the lowpass and just changed to 1.5 mH/30 uF to make them less "bassy" and lower the crossover frequency. Highpass is now 6.2 uF/0.8 mH with D220Ti on PRX waveguide. Yes, the forward axis moved down.

I haven't quit on the QSC; just acquiring more experience with the variables prior to tackling it again....

 

[rvsixer]

Center Channel

So let's say one builds a L/R set of e'waves, but finds a phantom center lacking for HT.

Besides the obvious solution of completing another and standing it up vertically (not an option in my case), are there any horizontally oriented arrangements that would/do work well?

 

[Zilch]

I've only ever done one center channel, and that was several years ago, a 4425 JBL butt-cheek flanked by two 8" JBL 2118 drivers. There are certainly eWave options to be explored, e.g.:

I have no clue whether it would work worth a whit, but JBL makes similar happen:

And there is always this:

http://manuals.harman.com/JBL/HOM/Technical Sheet/SK2-1000 Hercules ts.pdf

 

[Bauhausler]

I've only ever done one center channel, and that was several years ago, a 4425 JBL butt-cheek flanked by two 8" JBL 2118 drivers. There are certainly eWave options to be explored, e.g.:

I have no clue whether it would work worth a whit, but JBL makes similar happen:

And there is always this:

http://manuals.harman.com/JBL/HOM/Technical Sheet/SK2-1000 Hercules ts.pdf

If I had a big enough 20L cabinet I'l be tempted to try that with 2 B110s and a port. Probably sound very nice.

 

[Zilch]

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=302-743

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=302-742

 

[skywave-rider]

Your box volume is larger, so Fc is slightly lower. We can compare impedance measurements to substantiate that, if you want. :yes:

I also had too much LF comp in the lowpass and just changed to 1.5 mH/30 uF to make them less "bassy" and lower the crossover frequency. Highpass is now 6.2 uF/0.8 mH with D220Ti on PRX waveguide. Yes, the forward axis moved down.

I haven't quit on the QSC; just acquiring more experience with the variables prior to tackling it again....

Zilch, I am still working on getting WT2 to work on the MAC at home, so hopefully comparing impedance will be possible.

I think it's time to do the dunk-test to get volume displacement for QSC/driver. Unless somebody has that already.

 

[Pio1980]

So let's say one builds a L/R set of e'waves, but finds a phantom center lacking for HT.

Besides the obvious solution of completing another and standing it up vertically (not an option in my case), are there any horizontally oriented arrangements that would/do work well?

I don't see that happening. Two midrange drivers in one channel are by nature problematical, and the woofs are the lower mids in this set-up. Two woofs bracketing the tweet will create 3 midrange sources giving a blurred center-of axis and a complex & unpleasant horizontal venetian blind effect. Having the tweet and one woof handling the mids thru the cross-over region side-by-side will create a single sweet spot on the horizontal axis in the center speaker, not a desirable result. Forget it. Go for a more modest smaller center channel using the 6x6 with a small mid-woof in a vertical alignment.

 

[Zilch]

Zilch, I am still working on getting WT2 to work on the MAC at home, so hopefully comparing impedance will be possible.

I think it's time to do the dunk-test to get volume displacement for QSC/driver. Unless somebody has that already.

O.K., I'll measure the impedance with WT2 and save it to compare later.

Nobody's measured the displacement volume of QSC/DE250 as yet, I don't believe.

Here's what happens with the two different lowpasses, and none, for 123A-1:

Lowering the crossover frequency to 1.533 kHz cleaned up the vertical polars; the forward axis is now midway between the drivers, and the nulls are symmetrical about that axis:

There remain issues to resolve in the filters; this combo is a roller-coaster ride on-axis:

 

[HypnoToad]

Quick question probably for Zilch:

How does the 4425 studio monitors stack up against the econowaves?

How do the 4425's go in the pecking order and how do they sound?

 

[Zilch]

I don't see that happening. Two midrange drivers in one channel are by nature problematical, and the woofs are the lower mids in this set-up.

I've only ever seen one comprehensive analysis of how the popular D'Appolito MTM alignment works when deployed horizontally, which appears in Toole at Fig. 18.18, as provided by Harman's William Decanio. The solution when using conventional drivers is adding a real midrange driver stacked under the tweeter on the centerline, allowing the widely spaced woofers to be turned off at a lower frequency. Whether similar difficulties occur when using a relatively low-crossed waveguide is undetermined.

How does the 4425 studio monitors stack up against the econowaves?

How do the 4425's go in the pecking order and how do they sound?

4425s are classics using Keele's biradial horns. Well-designed and constructed eWaves can give them a good run. Newman said it: EconoWaves have the potential to be very good, indeed.

To approach 4430 performance, however, upgraded waveguides and drivers are prerequisite; I have little doubt that a skilled designer could exceed their performance by incorporating more evolved tools and materials using the design concepts we are exploring here.... :yes:

 

[Rock&Roll]

Argh, pyle waveguides are still on backorder. 1/22 it says now:bash::uzi:

 

[Bauhausler]

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=302-743

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=302-742

I knew you were going to say that.

From the horridly complex XO schem of teh Hercules it looks like the woofers are identical but one is a LF '.5' helper-outer.

 

[Stephen J]

Wave guide template ?

Ok, I would like to get the new baffle boards for my Aristowaves done today.
Rage supplied me with the drivers and JBL wave guides. Is there a template or at least mounting measurements.For cutting out the hole for the wave guides available ? :scratch2:
Thanks,
SJ

 

[rvsixer]

And there is always this:

Thanks for the responses so far guys! I think I might be able to swing something like this, maybe with just one woofer (so LCR would have all the same driver configuration, designed so the center has the same box volume as LR, etc). Decent plan :headscrat ?

 

[isaeagle4031]

Zilch has anyone tried the e-wave combo using a Dayton 8" waveguide? I'm considering this for a build I maybe undertaking soon. It will be flanked with a pair of 8" drivers or possibly a single 12". Not critical listening, but the listeners will be at varying heights constantly (some sitting, some standing).

This is the waveguide I am referring too...http://www.parts-express.com/pe/showdetl.cfm?Partnumber=270-308

They will flank an 11' wide by 8' screen. This is for the kids area of our church.

 

[jackgiff]

Neo is nifty.

The BMS 4540ND's finally arrived late yesterday, and I was stunned at their size compared to the standard D220Ti. Neodymium sure makes a difference in size doesn't it? Let's hope the old saying "Good things come in small packages," is still true.

 

[djnagle]

Zilch has anyone tried the e-wave combo using a Dayton 8" waveguide? I'm considering this for a build I maybe undertaking soon. It will be flanked with a pair of 8" drivers or possibly a single 12". Not critical listening, but the listeners will be at varying heights constantly (some sitting, some standing).

This is the waveguide I am referring too...http://www.parts-express.com/pe/showdetl.cfm?Partnumber=270-308

They will flank an 11' wide by 8' screen. This is for the kids area of our church.

I did it with the 12" version. I did not measure it though. Thought it sounded good. Seem to have better imaging but the sweet spot was much narrower.

 

[Zilch]

Is there a template or at least mounting measurements.For cutting out the hole for the wave guides available?

The outside dimensions are 12" x 6.5". I cut 0.75" smaller at the sides, so 10.5" wide, and 0.625" top and bottom, 5.25" net. Compare to the dimensions the Bauhausler provided in his Large Advent upgrade article.

Thanks for the responses so far guys! I think I might be able to swing something like this, maybe with just one woofer (so LCR would have all the same driver configuration, designed so the center has the same box volume as LR, etc). Decent plan :headscrat ?

As Bauhausler points out, the second woofer is run in "0.5" mode allowing the use of smaller diameter woofers and a more compact package.

Zilch has anyone tried the e-wave combo using a Dayton 8" waveguide? I'm considering this for a build I maybe undertaking soon. It will be flanked with a pair of 8" drivers or possibly a single 12". Not critical listening, but the listeners will be at varying heights constantly (some sitting, some standing).

None that I know of, though several of us have modded KLH-17s and 20s using the Dayton elliptical. I recently saw some measurements indicating that the 12" round does not provide constant directivity, though I've never checked any of those out myself.

I'd suggest building standard eWaves for use with that large screen, or the 6" square eWaveguide, which is 90° x 90° dispersion.

The BMS 4540ND's finally arrived late yesterday, and I was stunned at their size compared to the standard D220Ti. Neodymium sure makes a difference in size doesn't it? Let's hope the old saying "Good things come in small packages," is still true.

WAY cute, Jack, though you may have to move the crossover frequency up a bit per the factory specs. I've played them down to 1.3 kHz with LR4 filters like JBL does in one product, but it was a "push," and did not sound as good as up closer to 2.0 kHz....

 

[skywave-rider]

The BMS 4540ND's finally arrived late yesterday, and I was stunned at their size compared to the standard D220Ti. Neodymium sure makes a difference in size doesn't it? Let's hope the old saying "Good things come in small packages," is still true.

Jack, are you putting those on the 6x6 waveguides?