I have been wanting to try out a waveguide setup, so I bought a pair of SEOS-12 waveguides and I am going to use a pair of B&C DE250's that I picked up a while ago.
I have been using Hornresponse to try and choose a Pro woofer for this but the results that I keep getting show a pretty big roll off above 1 kHz for almost all Pro woofers (or at least 12" ones).
I am not sure if that is an artifact of hornresponse or it is real but it does not agree with the Eminence Suggested Cabinet Design paper graphs.
No surprise that the Eminence Delta Pro 12a and the Faital Pro 12PR310 seem to show the flattest FR and extension, but hornresponse still shows them 6 to 10 dB down at 1300 Hz.
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My best guess is that since many have built Econowave type cabinets using all kinds of Pro woofers, the simulations that I am doing have some kind of flaw.
I have not tried AKABAK yet.
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I thought of another approach that uses a speaker that I am familiar with, the Eminence Alpha 8a.
If I used 2 Alpha 8a's, my simulations show about the same SPL response as a single 12" and the 8a has frequency response that goes much higher (in the sim).
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What I don't know is if there will be comb filtering problems like those encountered in a line array.
So my question is, will there be problems if I built a 2^ft.cabinet using 2 Alpha 8a's?
I should say that this cabinet will sit on top of a 12" woofer cabinet and be hi-passed at about 100Hz BW2 or taller.
And a picture tells a 1E3 words so.
Thank you,
and tell me I am wrong about the sims of 12"ers
I have been using Hornresponse to try and choose a Pro woofer for this but the results that I keep getting show a pretty big roll off above 1 kHz for almost all Pro woofers (or at least 12" ones).
I am not sure if that is an artifact of hornresponse or it is real but it does not agree with the Eminence Suggested Cabinet Design paper graphs.
No surprise that the Eminence Delta Pro 12a and the Faital Pro 12PR310 seem to show the flattest FR and extension, but hornresponse still shows them 6 to 10 dB down at 1300 Hz.
.
My best guess is that since many have built Econowave type cabinets using all kinds of Pro woofers, the simulations that I am doing have some kind of flaw.
I have not tried AKABAK yet.
.
I thought of another approach that uses a speaker that I am familiar with, the Eminence Alpha 8a.
If I used 2 Alpha 8a's, my simulations show about the same SPL response as a single 12" and the 8a has frequency response that goes much higher (in the sim).
.
What I don't know is if there will be comb filtering problems like those encountered in a line array.
So my question is, will there be problems if I built a 2^ft.cabinet using 2 Alpha 8a's?
I should say that this cabinet will sit on top of a 12" woofer cabinet and be hi-passed at about 100Hz BW2 or taller.
And a picture tells a 1E3 words so.
Thank you,
and tell me I am wrong about the sims of 12"ers
Attachments
You can simulate the two Alpha 8's using the program "The Edge". This can work but there will be some lobing due to interference at high frequencies and/or high angles up or down. Since vertical off axis response window does not need to be that large you will probably be OK as long as you don't cross above 2kHz. In any case I would keep the cone driver as close to the horn as possible.
IIRC the classic Econowave design is with a 12" woofer and horn. I think the SEOS 12 can operate down to the low 1kHz range but I am not sure about that specific compression driver.
IIRC the classic Econowave design is with a 12" woofer and horn. I think the SEOS 12 can operate down to the low 1kHz range but I am not sure about that specific compression driver.
Yes, in vertical direction.
But since an acceptable vertical window is often only +/- 10 degrees I don't see a problem if you cross over below 2kHz, which is totally doable with the horn in question.
Thanks for that.
I kinda knew that something was wrong with the simulation because so many people have built
Econowave type speakers using 12" drivers.
I guess I will just choose one of the popular drivers, within my price range of course.
Then I can measure it myself and decide where to XO it.
I may be better off using a 10" as I really need a midrange, not a woofer.
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The SEOS-12 lists 950 as minimum XO but most seem to cross the B&C DE250 between
1200 and 1300 Hz when mounted in the SEOS-12 waveguide.
1600 Hz is the recommended XO for full power (60 W).
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I am pretty familiar with the whole comb filtering problem and experienced it first hand on a MMMTM column until I made it a WWMTM.
With Dayton PA130's it sounds pretty good and really puts out.
It is more of a small PA for my Synth's. See below
Thanks,
Dave
tn_WWMTM PA.JPG
Attachments
You can always roll off one of the eights earlier in a dual woofer design, compensating baffle step roll off, and eliminating the comb filtering at higher frequencies, effectively a 2.5-way design. I was actually just recently thinking about a SEOS-8 or 10 design with two B&C 8FG51s in a TQWT, for a fairly slim profile floorstander that will still move a lot of air.
Not to hijack your thread, but I was wondering actually if somebody knows (maybe Jack has said something about this already) if its possible to get the SEOS waveguides directly from poland, since the diy sound groups website ships everything via USA, which would be a bit of a waste seeing how the parts are made here in Europe....
Not to hijack your thread, but I was wondering actually if somebody knows (maybe Jack has said something about this already) if its possible to get the SEOS waveguides directly from poland, since the diy sound groups website ships everything via USA, which would be a bit of a waste seeing how the parts are made here in Europe....
In Europe you can buy this WGs/Horns here:
Horns
One pair of Iwata 600 in a small package was about 80 Euro for transport with 'Schenker Group' from Poland to Germany.
If you ask them they give you a pricelist of their Horns. Don't forget to add polish Tax to that. It was about 23% if i remember it correctly.
Edit.
A Seos 12 is about 100 Euro each + Tax + transport
It seems they don't have the cheap polycarbonat Horns
Horns
One pair of Iwata 600 in a small package was about 80 Euro for transport with 'Schenker Group' from Poland to Germany.
If you ask them they give you a pricelist of their Horns. Don't forget to add polish Tax to that. It was about 23% if i remember it correctly.
Edit.
A Seos 12 is about 100 Euro each + Tax + transport
It seems they don't have the cheap polycarbonat Horns
Last edited:
The problem with a lot of 12" woofers isn't rolloff at >1k so much as breakup peaks there or higher. Usually the challenge is attenuating those peaks while still allowing for a decent crossover region.
You really can't model the breakup performance (or, really, any of the HF response) of a woofer. As said previously, use real data for that.
You really can't model the breakup performance (or, really, any of the HF response) of a woofer. As said previously, use real data for that.
Many pro speaker companies offer several 12" versions, this one is perhaps the smoothest Beyma 12MW12Nd
http://profesional.beyma.com/ingles/xls.php?xls=01_LOWMIDFREQUENCYDRIVERS
http://profesional.beyma.com/ingles/xls.php?xls=01_LOWMIDFREQUENCYDRIVERS
I have here written down that someone did a dunk test, and found the QSC waveguide with DE250 to be 4.8L. The seos12 is not as deep, and not as tall. So maybe 4L?
Just a guess
I have a seos12 and DNA360 (de250 copy), but no means to measure liters or cubic inches(feet) easily right now.
It's easy with rice if you have way to measure the volume.
I plan on using sealed cabinet, so any minor discrepancies are not worth investigating.
Just a guess
I have a seos12 and DNA360 (de250 copy), but no means to measure liters or cubic inches(feet) easily right now.
It's easy with rice if you have way to measure the volume.
I plan on using sealed cabinet, so any minor discrepancies are not worth investigating.
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