Zilch's AK Design Collaborative - Econowave Speaker

[Zilch]

I should really be leaving this ewave stuff alone for my own good.

Bah.

You'll have a pair playing in less than an hour there.

I think I have a pic of the chip amp I'm working on for a Make Magazine feature.

A one-knob solution!

That's gonna run some high-efficiency eWaves quite nicely, I betcha.... :thmbsp:

 

[Bauhausler]

Bah.

You'll have a pair playing in less than an hour there.



A one-knob solution!

That's gonna run some high-efficiency eWaves quite nicely, I betcha.... :thmbsp:

I hope to showcase my LS3/5Awaves (JBL 6") with this in the magazine photos. That'll cause a few heart attacks.

There's a source selector/mute switch under the vol knob and now a power switch on the back flange.

It puts out 12.5 WPC into a 6 Ohm load, which is plenty for many applications.

I've built far fancier amps but this had to be greatly simplified in materials and complexity for the magazine readership.

I have to Ewave a pair of NLAs next week, then my next speaker project will be converting my 'new' DQ10s to QSC/DE250, since that's an easy build.

After that I have these freshly Rosewood veneered Kef 103.3s that I've been waiting to finish.

Lotsa projects.

 

[Zilch]

8" Square PT-D95HF-1 in AR4x

See pic @ #8897 above, right.

Vertical Polar Map:

Using the vertical polar protocol developed for QSC system measurements, we locate the forward axis via mapping the response in 3" height increments above and below the waveguide axis at a 44" mic distance from the baffle face:

Limited about the forward axis:

-3" to +9" relative to the waveguide axis, the forward axis is at arctan 8/44 = +10.3° from there.

Lower Null:

Well developed at full depth -40 dB, orange, the lower null is at WG -15" or arctan -15/44 = -18.8°. C/C distance is ~8.19".

Upper Null:

At WG +43.5", yellow, arctan 43.5/44 = +44.7°, the total forward lobe then being 44.7° + 18.8° = 63.5° tall when referenced to the waveguide axis.

Crossover:

eWave <95 dB standard highpass, lowpass = 2.5 mH/15 uF for this woofer; minimum phase on forward axis, black, inverse polarity null there, grey:

Four Drivers:

Two D2500Ti-Nd and two D220Ti:

Stunning max continuous 117 dB/1m SPL exceeds THX spec for HT mains:

http://www.jblpro.com/catalog/support/getfile.aspx?doctype=3&docid=1080

 

[ROSSO]

O.K., so much for the break:

http://www.jblproservice.com/pdf/AE Series Compact Models/AC1895-WH.pdf

Any particular reason you chose the 364700 90x50 WG over the 365124 120x60 WG? Both 8" square, 1" threaded from the AE series. Looks like the 365124 factory x-o was at 1.6kHz.

http://www.jblpro.com/catalog/support/getfile.aspx?doctype=3&docid=1079

 

[Zilch]

Any particular reason you chose the 364700 90x50 WG over the 365124 120x60 WG? Both 8" square, 1" threaded from the AE series.

http://www.jblpro.com/catalog/support/getfile.aspx?doctype=3&docid=1079

The pattern is consistent with the eWave standard 90° horizontal x 50° vertical despite its square form factor.

120° would be considered wide dispersion, and probably preferred for surrounds. In theory, that is the max practically achievable using PT design principles, though multiple 90° will get to 180° and beyond easily. Allison max dispersion enthusiasts have not yet picked up on that one.

Now that I've heard this, I'll be ordering some on Monday to test.

Of note: EconoWave just rolled past a phenomenal half-million views.

[Are we having fun yet...? ]

500022/8904=56.1570​

 

[RevBillyBob]

Wide Dispersion Wave Guide

I have a newbie question that I hope some one can help me with. I have an old back loaded horn that my father built in the 60's. It has two jbl d208s in it.
I only have one, so it is a mono system. Right now I have a fostex super tweeter on it, but it doesn't reach down low enough and it needs more dispersion. Can anyone suggest a good wave guide and crossover frequency to complete this system? All help is appreciated.

 

[Zilch]

Welcome, Rev!

You say "on" it, so I assume that means sitting on top. Any of the eWave options will work for you; 6" square, 8" square, 12" X 6.5", or the big 14" X 10" QSC waveguide.

Your horn-loaded dual d208s are likely a high-efficiency combo, so use the >95 dB crossover variant.

We'd like to see a pic or two, of course, which might trigger a preferrable option among these (and a couple of other "unofficial" ones).... :thmbsp:

 

[RevBillyBob]

Here's a picture. The plan is from an old issue of Audio magazine. The wiring and the cigar box crossover are temporary.

 

[Zilch]

Very nice!

I believe I'd make a similar style box to house the standard eWaveguide and crossover and set it on top.... :yes:

 

[Zilch]

Update above -- data from four drivers and the lower null. I'll see if I can find the upper one....

http://www.audiokarma.org/forums/showthread.php?p=3302600#post3302600

Conclusions?

 

[ROSSO]

Here's a picture. The plan is from an old issue of Audio magazine. The wiring and the cigar box crossover are temporary.

Hmmm....D-208 is an 8" driver, since only one works, and you are doing mono, replace the dead D208 with one of the 8" waveguides? What issues would there be with the resulting horizontal arrangement???

 

[donprice]

Hmmm....D-208 is an 8" driver, since only one works, and you are doing mono, replace the dead D208 with one of the 8" waveguides? What issues would there be with the resulting horizontal arrangement???

Vertical null becomes a horizontal null? May or may not be an issue depending on listening position.

I believe the OP meant only one cabinet, not only one working D-208.

 

[ROSSO]

Vertical null becomes a horizontal null? May or may not be an issue depending on listening position.

I believe the OP meant only one cabinet, not only one working D-208.

EDIT: Ahhh. I misread his intent. Both D-208's are working, only in the same cabinet, apparently?

 

[Bauhausler]

Happy 500K, Econowave

I don't know what Zilch takes to keep his temper cool through 8900 posts and innumerable repeat questions, but I'd like to get a bottle of it for the elementary school where I work.

Half a million hits. That's 99th percentile for discussion threads.

Okay, lurkers. It's time to come out of the woodwork. The info's all here. The sound is outstanding. Go Ewave and you'll never go back.

As soon as the camera recharges I'll post pix of an ewaved DQ-10. Since I've already done a pair of LS3/5As this was the next sacred cow that needed slaughtering.

 

[Zilch]

Heh.

Just ran across this classic post:

Nah. I've done 2 conversions on Advents and that's one more than I planned. I'm off to cause trouble with other vintage speakers.

********

As soon as the camera recharges I'll post pix of an ewaved DQ-10. Since I've already done a pair of LS3/5As this was the next sacred cow that needed slaughtering.

Slam dunk, just like Dj's AMT-1s -- the grille keeps the secret.... :tongue:

 

[Bauhausler]

Heh.

Just ran across this classic post:



********
Slam dunk, just like Dj's AMT-1s -- the grille keeps the secret.... :tongue:

DQ-10s:


I'll have to check the Fs of these woofers. One or both may have been refoamed and I'll want the correct foam/resonant freq on both for best performance.

It's tempting to screw the WG to the screen of the grille rather than working out brackets, but that would be cheating.
One thing I can do is relocate the grille. There's considerable room to shift its position. I can move it downward about 6" to lower the visual height of the speaker. It can be shifted and tilted forward as much as 3" to allow the WG to be placed farther forward. It just requires drilling a few new holes.

Right now I'm running the 'stock' ewave XO for low sensitivity woofers. I assume this can be improved by changing to the values in the latest DE250/QSC crossover version.

They sound pretty good right now, roughly assembled and without any dialing-in.

 

[Zilch]

I sure wish the bass bins were mirror-imaged, and I've contemplated doing that, actually.

From my recent studies, I'd suggest the waveguide should just be flushed with the front baffle using eWave standard inverse polarity; it doesn't need to hang in front, I don't believe. It's easy enough finding the forward axis with your RTA and the HF inverted again, now that we know where to look for it.... :yes:

 

[Bauhausler]

I sure wish the bass bins were mirror-imaged, and I've contemplated doing that, actually.

From my recent studies, I'd suggest the waveguide should just be flushed with the front baffle using eWave standard inverse polarity; it doesn't need to hang in front, I don't believe. It's easy enough finding the forward axis with your RTA and the HF inverted again, now that we know where to look for it.... :yes:

My wife mentioned the asymmetry. I ignored the remark, preferring other technical activities rather than moving a woofer 2" .

So the WG can be flush with the baffle. I actually get a somewhat smaller c-to-c distance when I overhang the WG edge. The QSC has a very shallow depth at the flange and the WG can be moved quite low with just a little horizontal forward displacement. I'm gaining 2" of c-to-c reduction by setting the WG forward 1", which is still well clear of the woofer's radiation pattern.

Are you referring to this flush mounted geometry for the original Ewave XO or for the new DE250/QSC crossover values, or for both?

I'm really supposed to be finishing that chip amp. It's 3 solder joints from done so of course I clean house, call friends, fool with speakers, take a nap....

 

[Zilch]

I'm talking about QSC in the Trap cab. 10.5" C/C, the woofer's mounted behind the 3/4" baffle, and with the filters I worked out, the forward axis is normal to midway between them. If you mount flush, like Jack did, it should give you ~6.8° of upward tilt, no?

 

[djnagle]

This worked for me Ross. Just screwed in the bottom three holes and put a piece of rubber pad under the driver. Worked great.