Zilch's AK Design Collaborative - Econowave Speaker

[DonQuixote99]

Zilch would invert the speaker to put the waveguide in alignment with the measuring microphone. Woofer on bottom, waveguide on top for normal listening 'on axis'.

You know, I wouldn't throw the baby out with the bath water here. That Model 14 crossover might not be all that bad... especially considering all the work Zilch was doing with the Model 19.

The fact may not have jumped out, and the pics sort of suggest otherwise, but all I have a source for is those woofers. Would be building cabs & crossovers. Unless I just happen to stumble across some good 4+ cu ft cabinets around here....

 

[dumptruck]

The fact may not have jumped out, and the pics sort of suggest otherwise, but all I have a source for is those woofers. Would be building cabs & crossovers.

I think you should try hard to track down measured response >1000kHz, so you can figure out if you're likely to have any trouble with the crossover.

 

[JoMoCo]

Altec 12" 9842 Woofers

So, if one had such woofers, how might one proceed? Build a box about the size that Altec put them in? That would be, based on published external dimensions and material thickness, about 4.2 cu.ft., in the case of the 9842. There’s even a blueprint for a 9842 cabinet online. (Duplicating the Model 14 cab, of course, would be a lot more work. Internal volume is similar at about 4.08 cu ft.)

So, while I am keen to take these woofers and build killer e-Waves with them, I'm also a bit at sea here, mainly with regard to the crossover. Am I encouraged to dive in?

Those are ideal candidates for "Evan waves". A simple way would to use the 9842 cabinet with the QSC waveguide, just rotate 90 degrees so the 28" is the height. You could just use the altec lowpass and the zilch QSC highpass and adjust as necessary, go for it....:scratch2:...:thmbsp:

 

[DonQuixote99]

I think you should try hard to track down measured response >1000kHz, so you can figure out if you're likely to have any trouble with the crossover.

Yes, data would be a wonderful thing. What I have is this bit from a 2006 thread here:

My Altec 14's have a light coned 12" woofer that has good output above 2 kHz, the little CD horns unload below 2 kHz, so I

use a 2 kHz crossover. The horns are attenuated about 12 dB to match the woofer.

Richard C.

I take it that the 'light cone' isn't a special or replacement, but was OEM for the Model 14 woofer?

 

[DonQuixote99]

Those are ideal candidates for "Evan waves". A simple way would to use the 9842 cabinet with the QSC waveguide, just rotate 90 degrees so the 28" is the height. You could just use the altec lowpass and the zilch QSC highpass and adjust as necessary, go for it....:scratch2:...:thmbsp:

Basic problem with that is I don't have an Altec lowpass. Woofers are available, but no other Altec parts (from the seller I'm talking to, at least). Will need a whole crossover design/build.

 

[JoMoCo]

That's not a problem, That's a potential project!

Basic problem with that is I don't have an Altec lowpass. Woofers are available, but no other Altec parts (from the seller I'm talking to, at least). Will need a whole crossover design/build.

The budget route you may want to start with is use the research already done and then tune from there.

Following the Zilch plan...prototype, test, modify, finalize...I would suggest getting a schematic for a model 14 or an 9842 for the Altec implementation of the woofer and then blend that low pass prototype crossover design with the Zilch high pass, test/measure, modify if necessary, enjoy.

The advanced route involves measuring the Altec woofer driver parameters from the get go with test gear and then proceding as documented as in other builds on this thread and on the Flex your PCD mettle over on the techtalk thread...:thmbsp:

The just the woofers are all you need to start... all other parts can be obtained from the vendor of your choice...:scratch2:

http://www.lansingheritage.org/html/altec/specs/pro-speakers/9842.htm

 

[DonQuixote99]

Emailed Richard C., and have heard back from him. He's got some helpful data. Yes, these are light cone woofers that get to 2000 Hz nicely, he says. That's where he crosses them over. As for the "Altec low-pass filter," there's no such animal. Altec ran them full range.

 

[JoMoCo]

Emailed Richard C., and have heard back from him. He's got some helpful data. Yes, these are light cone woofers that get to 2000 Hz nicely, he says. That's where he crosses them over. As for the "Altec low-pass filter," there's no such animal. Altec ran them full range.

If that is true and you want to go "Zu style", then it will make your first take very easy, but the schematic will tell all. I don't recall Zilch ever running anything but a low pass to prevent issues with full range operation above the drivers intended linear performance zone...:scratch2:

If you read the Altec docs in the link provided earlier, they state crossover point used is 1500hZ in their last and possibly their best interation with a 12" woofer paired with a 1" compression driver, the 9842...:yes:

 

[gainphile]

Check this out!

Econowave Standard WG + DE250:

Fulll story here...

Using AU$9 plastic adapter from DJCity (local prosound shop)

Normalised:

The adapter needed to be modified to fit flush with DE250:
- Enlarge the original small hole to exactly 1"
- Enlarge 3 mounting bolt holes
- The thread is not perfectly matched. Fill 1mm throat gap with bluetack.

 

[jhoyt]

In the space of a couple days I "broke" both of my D220Ti drivers. :tears: I was doing some work to the crossovers (charge coupling) and drivers (damping the backs), so I connected and disconnected them several times. Well, evidently that's all it takes to break the VC wire leads...

Time to order some replacements from PE. Good thing they're cheap.

 

[BlueFlyingV]

Been messing with these at my shop over the last month or so. JBL 2214H and QSC/DE250 combo. Crossover is the Deluxe version. So far I really like these alot. As others have mentioned, I think the DE250 is alot smoother than the 220ti at higher volume. Low end sounds great so far also. It's pretty tough to judge them fully at my shop because the place is like a damn echo chamber. Pretty sure these will be veneer worthy though. :thmbsp:

More pics to come when I get them purdy.

 

[jhoyt]

That looks fantastic! Bet they sound wonderful.

 

[juniorJBL]

BlueFlyingV Those look great!!

They should have some great low end. :thmbsp:

Nice job!

 

[DonQuixote99]

Dang BlueFlyingV! Those look just about exactly like what I'm figuring on doing with the Altec woofers! Ideas follow function or something....

Very nicely done!

 

[4343]

Been messing with these at my shop over the last month or so. JBL 2214H and QSC/DE250 combo. Crossover is the Deluxe version. So far I really like these alot. ...

Nice cabs!

That combo does work pretty nice.

Kinda wish mine were straight like yours. Mine are angled back, and I can't help noticing that the sound just a tiny bit better standing, vs seated.

 

[CraigB]

Grills on!

Thanks for the compliments on my EconoWave version! I got the grills done today. PE neo magnets under the veneer, 3/4" plywood frame, PE premium black grill cloth glued on with 3M Super 77 spray contact cement. Here are some pics.

 

[4343]

Check this out!

The adapter needed to be modified to fit flush with DE250:
- Enlarge the original small hole to exactly 1"
- Enlarge 3 mounting bolt holes
- The thread is not perfectly matched. Fill 1mm throat gap with bluetack.

That looks pretty good! I tried that with a JBL driver a while back, my adapter was aluminum. It too needed to be bored out to be 1".

If I had the plastic adapter, I would bore it even larger, eliminating the threaded "snout" in the process, as well as the threaded portion of the waveguide. The long un-tapered section that is in the adapter sounds a little "off" to me, so I did that once before, pic on page 524 of one I made from plywood:

http://audiokarma.org/forums/showthread.php?p=3154464#post3154464

Fourth post down.

The DE-250 has either 2 or 3 bolt patterns, the 2 bolt would work best for this, I had to use very small Allen head screws to mount anything with 3 bolts.

 

[gainphile]

Econowave #115... with paint !

Red sounds better

I need to reconfigure the DSP due to volume changes.

 

[juniorJBL]

Red sounds better

Do you think the Red is better imaging or better bass or both!



Nice job!!:thmbsp:

 

[DonQuixote99]

Hey GP, how'd you get that paint so nice and smooth? Looks great!