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Zilch's AK Design Collaborative - Econowave Speaker

Russellc said:
Schumacher,how much difficulty do you think it would be to adjust it to the JBL 2235H,
also using the QSC and DE 250? This is what I intend to TRY to suss out once measuring system is up and running.

Thanks for any advice you may have on where to start would be greatly appreciated.

Russellc
Click to expand...

I couldn't say. I'm not familiar enough with the JBL to come to any conclusions.

The Lambda's have quite extended response that is smooth to cutoff, past the XO point. If the JBLs are similar in their high end extension, then a slightly more complex filter than a simple LC second order will probably be necessary to shape the response to match the the tweeter/waveguide combination.

If you could provide some FRD and ZMA files, or response plots of the woofer in the enclosure along with impedance plots, I might be able to take a stab at a first shot.
 
doucanoe said:
A question for P. Schumacher or Zilch?

Concerning the 5-piece x-over for QSC/DE250. I assume values have been selected for 8 Ohm top and bottom. I have access to a pair of 2225J and may want to try those out for that particular project. Any suggestions as to how to deal with that in the crossover. I could use 16 Ohm across the terminals but I'm not sure if that would be the proper way to deal with that. It would be nice if that would be the solution however as I could then use the x-over with an 8 Ohm woofer at some point and not have to reconfigure.

Any thoughts would be appreciated :yes:

RC
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A custom filter for the woofer needs to be created to match the module. Since the XOs are in parallel, it doesn't matter what impedance woofer you choose to go with the waveguide/tweeter/XO module. 16 Ohm would be fine. And if you do want to take a stab at using the existing XO for the 16 Ohm woofer, you would double up the inductor value and cut the cap value in half to form a similar transfer function for the 16 Ohm woofer. Tweeter level can be adjusted to match the woofer by changing only a single resistor value.
 
4343 said:
Funny That just happened to me at Wolfgang's Vault, I went over 500 songs in my basket (Freebies as a VIP member) and it won't download ANY!

/ EDIT> It Still Works! And to prove it, here's another view of the 8X8.

OK, Who's going to be the 10,000th REPLY? (Stuck @ 9999 on the front page...

And The Winner Is! RussellC!:thmbsp:

<End EDIT \
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Actually, it looks like you get the honors, congrats!

russellc
 
juniorJBL said:
And imagine Zilch had already done all this before starting this thread!:yes:
Click to expand...

Actually, more than once if you count all the threads at LH forums as well, there's the 2 famous Q&D threads, the Babies thread, the 4430 help thread, and others that arent coming to mind right now...

Russellc
 
Schumacher ® said:
I couldn't say. I'm not familiar enough with the JBL to come to any conclusions.

The Lambda's have quite extended response that is smooth to cutoff, past the XO point. If the JBLs are similar in their high end extension, then a slightly more complex filter than a simple LC second order will probably be necessary to shape the response to match the the tweeter/waveguide combination.

If you could provide some FRD and ZMA files, or response plots of the woofer in the enclosure along with impedance plots, I might be able to take a stab at a first shot.
Click to expand...

As soon as I'm finished with the measuring setup, I'll do that, should be fairly soon. Those AE drivers do appear to be wonderful and easy to work with. If I recall, I think they are good to a smidge over 1000, (the JBL) then begin to drop off. I'll search over in the LH forums for some response plots, back in the Q&D days I think Zilch posted about every combination.

Unfortunately, I dont even have a passing familiarity with FRD or ZMA files, perhaps I can fix that! Are these file types doable with software like RTA, REW, HolmImpulse, etc.? I dont have the coin for CLIO!

Thanks for the input,

Russellc
 
Russellc said:
Actually, more than once if you count all the threads at LH forums as well, there's the 2 famous Q&D threads, the Babies thread, the 4430 help thread, and others that arent coming to mind right now...

Russellc
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Yeah I remember all the threads.:D lots of them and not including all the help to other people's builds.

I just liked the "Family Portrait".:yes:

Fun to read although my brain starts to run out of my ears from info overload.:yes:
 
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badman said:
Anyway, prebuilt pseudo-Econowaves with a cool format!
Click to expand...
Duke has been an advocate of constant directivity designs, at least since Wayne's 2005 meeting with him and Geddes in Tulsa, where Earl introduced Summa. There is certainly a history of collaboration toward similar design objectives.

We'd like to know what drivers Duke is using, of course, and I suspect Wayne's crossover topology is featured, as well. A big thumbs-up to commercialization of our favorite project here. :thmbsp:

[Are ZilchPlugz™ included...? :tongue: ]
 
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Schumacher ® said:
I couldn't say. I'm not familiar enough with the JBL to come to any conclusions.

The Lambda's have quite extended response that is smooth to cutoff, past the XO point. If the JBLs are similar in their high end extension, then a slightly more complex filter than a simple LC second order will probably be necessary to shape the response to match the the tweeter/waveguide combination.

If you could provide some FRD and ZMA files, or response plots of the woofer in the enclosure along with impedance plots, I might be able to take a stab at a first shot.
Click to expand...


Right now, at Zilch's suggestion, I am using the bottom half of the JBL 4430 monitor. Its very similar to the basic E'wave crossover Low pass, 12 uf capacitor (same as E'wave) and 2.7 coil...obviously a little larger than the standard 1.5 mh E'wave LP. I also have the zobel from the same 4430 monitor. HP is E'wave. Once the 5 piece crossover arrives, I will try the JBL lp as well as the new E'wave crossover's LP,( The 4430 used 2235H as the woofer driver) with the new HP.

thanks, Russellc
 
Schumacher ® said:
A custom filter for the woofer needs to be created to match the module. Since the XOs are in parallel, it doesn't matter what impedance woofer you choose to go with the waveguide/tweeter/XO module. 16 Ohm would be fine. And if you do want to take a stab at using the existing XO for the 16 Ohm woofer, you would double up the inductor value and cut the cap value in half to form a similar transfer function for the 16 Ohm woofer. Tweeter level can be adjusted to match the woofer by changing only a single resistor value.
Click to expand...


Thank you sir!


Point might be moot now, however. I just came into ownership of a pair of E 145-8's in 4625B cabs courtesy of AK member clmrt. Looks like I'm back to 8 Ohm for the time being anyway. They should be fun to play around with :yes:

RC

RC
 
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Zilch said:
ZMA and FRD may be derived via tracing:

http://www.audioheritage.org/vbulletin/showthread.php?t=10651

http://www.lansingheritage.org/html/jbl/specs/pro-comp/2235.htm

580042/10015=57.9173​
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Zilch, i was just looking at the first link you posted, Giskard's info on the 2235H. Sorry to be so thick, but if you will explain the "tracing" procedure, I'd be glad to give it a whirl. I need to learn all this anyway, and only so much can be done watching others swim in the pool. Time for me to dive in and be productive!:yes:

Thanks and ready to trace,
Russellc
 
Zilch said:
There's a software tool for doing it, but I never have.

[Pete'll show us how.... :) ]
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I would LOVE to do this, sounds like a valuable procedure to have on tap. I'm ready for my homework Pete! Lay it on me.:thmbsp:

I need to order a mic stand and boom..........and I guess this tracing software too. If anyone knows the name of this software, I'll get it ordered.

russellc
 
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