Serge,
Yes, the speaker's mass and suspension would need to be optimized for this situation - unless you align the bass response actively.
There are three main tradeoffs with respect to box design - box size, low frequency extension, and efficiency. Improving any one of these parameters requires degradation of one or more of the others. A speaker with very low frequency extension in a small box must necessarily be inefficient. A high efficiency speaker in a small box must necessarily have limited low frequency extension.
The major tradeoff in your design is box size. A whole room is a rather huge box. Assuming the system is properly designed, you could have a very efficient speaker with very low frequency extension. High efficiency might not seem like such an important parameter in a control room where the listening levels typically aren't extremely high. The great thing about efficiency, however, is that it allows you to reach a given sound pressure level with less power. And less power means less distortion.
If I had the luxury of building a speaker like this, I would use an array of large, high linearity, high efficiency drivers - two Aura Sound NRT 18-8s per channel, for example.
http://www.aurasound.com/proaudio/frameset2.html The natural f3 of this setup would only be about 90Hz. With active bass equalization, however, you could bring it down to 10Hz, critically damped, with a shallow 12dB/ocatave roll off! The tradeoff for all this deep tight bass is +16dB of gain at DC, but the efficiency of a pair of these drivers is a whopping 102dB/W/m. Subtract the 16dB and you get 86dB/W/m, which is the typical passband efficiency of most sub drivers. Driving these Aura speakers with a 200W amplifier could easily twist your guts and make your ears bleed in an average size control room. But a pair of these drivers can handle 1600W. 200W is nothing to them. So that gut twisting output would also be extremely linear!
Let me know if you need any help building such a monster!;) This would be a lot of fun!:D
Thomas
I was only dreaming. Living in a coutry, building a 30'X40' for some nice home cinema and using about the half of it(with concrete blocks, filled with cement, for the middle wall) as a near empty summer/winter stockroom and the other part as a music/cinema room, it would be an interesting project (remember I'm dreaming!)
