Ripole subwoofer, help needed a little

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Re: SLS

I dont know about some of you, but I find it more interesting to discuss about the topic rather than something quite irrelevant.

Calvin said:
A dipole featuring a parallel connected pair of SLS12 could have the following dimensions using 22mm MDF-board.
W: 360mm H: 390mm D: 340mm
Chamber front: W: 80mm
Chambers rear: W: 96mm
The Fs of the driver drops to 20Hz in zthis configuration.
Using a passive filter/EQ -which I strongly recommend- the Fs drops to ~16Hz and the response is linear between 21Hz-195Hz (F-3dB, nearfield).
Impedance stays above 2.7Ohms
Max. linear stoke is reached at 9.5V@20Hz, 17V@30Hz and 28V@40Hz respectively 20W, 70W amd 200W@4Ohms

This BMC-concept (aka ripole) seems very nice, but I wonder if there are any software which could be used to model these?

Calvin, you say that a dual SLS 10" or 12" could be used even without any electronic correction to boost the low end? What would a the efficiency of such bassunit? I'm asking this because I'm thinking of using these as the low end of a smallish 3-way speaker instead of a vented 8" or 10".

A BMC woofer seems to create some resonances around 200-300Hz. What would be the highest crossover frequency with let's say dual SLS 10" BMC?
 
Ok, so could somebody explain the efficiency behavior of ripoles? If I put two ~91dB SLS 12" in a ripole and connect them parallel to get 4 ohm impedance, will the (theoretical) efficiency of that ripole be:

A) ~97dB (same as IB without BSC)
B) 97 - 4.5 (or was it 4.8) = 92.5dB (I read this from somewhere)
C) 91 dB
D) something else?
E) a lot less?

If the efficiency is on the high side, how much should be used to compensate the dipole roll-off in the 20-50Hz range?
 
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