<Two Sheets, 43Hz Folded Horn

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The design constraints are: it must have -3dB low point of at least 45hz (43 would be good), flat from 45-130Hz, no more than three sheets of 4x8 plywood, and be under 60 cubic feet and reach 129dB in half-space.
Here are the thiele-small parameters of my 12PLB100:
Re=5.5
Fs=43.07
Qts=.37
Qes=.39
Qms=6.99
Le=1.77 (1khz)
Mms=77.17 grams
Vas=70.17 liters
Xmax=9mm
Here is the drivers diagram: http://www.bcspeakers.com/media/W1s...kvMzIvMzk2LzEyUExCMTAwLnBkZiJdXQ/12PLB100.pdf
 
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Does anyone else find it rude when someone starts a post with "Um", as if they are questioning the intelligence or diligence of the person they are responding to?

If they are asking for free help from a stranger, perhaps something like "Do you have measurements you could share?" might be more polite.

They're W-bins, and unlikely to reach particularly low. While I take your point, I can understand why the poster in question might be skeptical.

To the original poster, I've built a set of eight 15" subs that're around 70L internal (<3 cu.ft), which are good for over 120dB from 40Hz upwards. You need good drivers and a lot of power.

Chris
 
Does anyone else find it rude when someone starts a post with "Um", as if they are questioning the intelligence or diligence of the person they are responding to?

If they are asking for free help from a stranger, perhaps something like "Do you have measurements you could share?" might be more polite.

If the w bin was scaled up a bit to get more internal volume then it would probably go a bit lower. The right driver too would help.
w bins are very efficient spl wise, about twice that of a sealed box.
 
Not really a horn, but an offset MLTL can get you there within the constraints listed (One sheet of ply might be enough, in fact).

A sealed W-bin will have to be huge to get down to 43 Hz, and so will exceed the material limit of <2 sheets of ply.

A vented W-bin that's small enough to use less than 2 sheets of ply still provides gain at the wrong frequencies, so that's a no-go either.

A suitably-designed TH can get you close (e.g. my POC3, or a larger version of the THAM12). The problem here is that the upper cutoff frequency may not meet the 130 Hz limit. You might be able to get it reasonably flat between 100 Hz to 200 Hz on paper with stuffing between S1 and S2.

But I suspect that StainlessSteve might already have a solution :)
 

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I don't. I'm trying to use a folded horn within 60ish cubic feet down to 45hz up to 135hz at +129dB. What is the maximum SPL of this design and maximum SPL simulated spectrogram+group delay and phase?

Well, the MLTL design won't hit 129dB unless you put it in a corner, LOL. At that point 450W will give just over 130dB down to 40 Hz, but that's assuming no vent or power compression.
 
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