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In Reply to: RE: Choose a Low Pass posted by Mr_Steady on July 05, 2015 at 08:42:15
You said it was a three way speaker, which usually implies a direct radiating woofer. If what you meant was three separate sources that's something else entirely.
As for a source that goes from 140Hz to 15kHz, that would usually require at least two drivers to accomplish well. The same applies to 300Hz to 15kHz. Any single driver speaker, even if horn loaded, with adequate displacement limited output below 500Hz or so will usually have a very narrow dispersion pattern much above 8kHz.
Follow Ups:
Sorry this thread is a spill-over from the "How large is too large for HE" thread. It's all hypothetical.Tom Danley will begin work on a front loaded acoustic horn driven by 5" or so coax driver. It could have a -3db down point at 140, 175, or 250hz depending on the size of the horn at 108 to 110db efficiency. Let's just say it goes to 15khz.
I guess this thread was a way to explore the best bass bins for the given cutoff points.
When I think bass. I think front loaded bass horns. :)
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Big speakers and little amps blew my mind!
Edits: 07/05/15
My Quarter Pie would be a good match and get you down to 50 Hz, since it's about 5.5 feet.
https://community.klipsch.com/index.php?/topic/148054-quarter-pie-bass-horn-measured-fr-how2build-and-hornresp/
Claude I love it, but 48" by 48"?! Lordy that's big. You win!I would just as soon cover 100hz to 35hz with a PPSL. They are compact. For all my big talk, real bass horns are too big for me to fool with. I'm willing to cheat on the low end. :)
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Big speakers and little amps blew my mind!
Edits: 07/09/15
We should have been talking about PPSLs by now.
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Big speakers and little amps blew my mind!
"We should have been talking about PPSLs by now."
I agree.
I think a PPSL with a Danley Synergy mid-HF horn on top would be a good choice for high efficiency and reasonable size.
A LaScala sized cabinet would be able to do -3dB at 27hz, and over 100dB/2.83V/1M.
The plan and cut-sheet for the 35hz PPSL is online, about 104dB/2.83V/1M and useable to 250hz (using a Q=1 12dB low-pass it will have a LR24 low-pass function).
The 48 x 48 horn from claudej1 is fine, if you have the space, and you are planning on adding subs.
Well the Bat-signal does work.
Of the three low pass points, do you have a preference, and why?
The PPSL would mate well with the smaller proposed Fig.7 horn. If he builds a 4' long horn, maybe not so much. Of course it's the time alignment that is a key advantage. I bet all this talk of folded horns has been making TD squirm in his seat. :)
Djk, I have a question about PPSLs that has been nagging me. I'm sorry if it's a touchy subject, but if I'm confused about it, then probably somebody out there is also.
You've written that the PPSL goes up to 400hz or so, but then I read on another forum that the square shaped slot creates a 1/4 wave resonance. The slot looks to be a cube with one end open. Sort of like a cubed horn. I would imagine that a cubed shaped horn would do funky things, like produce a 1/4 wave resonance. These posters seem to say that this resonance relegates the PPSL to sub duties. What do you say about this?
With these rather low crossover points I guess it won't matter too much. Maybe the 12" driver PPSL would be a better fit for 250hz? Your newest iteration of the PPSL with the flared slot looks like it would solve this resonance problem. Really it looks like the drivers should be mounted in something like a waveguide as opposed to a cube.
Thanks,
Jamie
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Big speakers and little amps blew my mind!
"Maybe the 12" driver PPSL would be a better fit for 250hz? "
Yes.
EV made a dual 15 PPSL that was crossed at 800hz, but it got a little rough.
Art Welter made some extensive measurements on a double 15 PPSL that he built, it showed a small 3dB peak around 175hz, and was useable to 250hz.
The shallower the plenum, the higher the PPSL can go.
Thanks.
A 3db peak doesn't seem so bad. Nothing that can't be fixed with EQ. When I read the word resonance, it made me think of a sound quality anomaly like a hum or buzz, or a reverb quality to the effected point.
And the depth of the plenum is determined by the size of the driver?
You haven't given us any update on your new PPSL. The on that looks like a Belle, and has a flared plenum. Anything you would like to tell us about it SQ wise? FR wise?
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Big speakers and little amps blew my mind!
The 48 x 48 horn from claudej1 is fine, if you have the space, and you are planning on adding subs.> > DJK
That horn has great bass definition. In it's defense, it's low profile,a 48" RADIUS fits perfectly into a corner, and takes up less cubic feet than a LaScala when you think about how much "dead air" space is wasted with those 100 Hz. "short horns."
The PPSL sounds like a good way to go (very interesting optimization of DR's and ports), though, but it's NOT a horn, and there are no free lunches, eh?
"The bigger the horn, the better the horn"........Claude Jodoin
I like your horn Claude. I would probably stand it on it's side, so it's tall and long, but skinny. My problem is that I don't have even one good corner, much less two.
Like big horns? Check out the spiral bass horn from Inlow sound, 20hz to 140hz. I might actually lay this horn on it's side like yours. I wonder if you can go mono at 140hz, or is that too high?
No free lunch? Ain't it the truth.
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Big speakers and little amps blew my mind!
There is no corner required, it just fits in there quite nicely.
"but it's NOT a horn, and there are no free lunches, eh?"
It can be time-aligned without DSP, goes deeper, is simpler to make.
Oh, it will also have less distortion.
In a side-by-side test, the PPSL ate the Klipschorn's lunch, going deeper, and sounding cleaner.
Well, then I should built one just to see what you are talking about at last. link?
PPSL is a concept.I have plans and a cut-list on line for the 35hz PPSL with the Kappa Pro 15LF2.
I have one friend that bult one and used the Yung SD500-6 500W Class D Subwoofer Plate Amplifier Module with 6dB boost at 25 Hz in his home stereo.
He is using a pair of Klipsch HIP for the tops.
Edits: 07/12/15
Hello Djk,
On diyaudio you have wrote that port is 2,5'' high but from drawing it seems its 4''. 32(B) - 9.125(E) - 9,125(E) - 7.5(F) - (3*0,75).
So I'm wondering which one is incorrect?
I'm tempted to built this one with 2xKappaPro15LF2. I'll have to rearrange it because my limiting boundaries are slightly different (W.30/D.18/H.36).
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