Well there's the Fletcher-Munson Curve (I almost called it Nelson Munson... HAH HAH!) and then the fact that sub-bass requires a long distance to reproduce the actual waveform.
The further you go above about 85dB, not only do you get more harmonic distortion from the ear/brain system, but you lose sensitivity to the bass. This becomes very abrupt and exaggerated at a certain point due to the stapedius reflex, which just dumps sensitivity to deep lows and good perceived distortion characteristics (surprisingly not so much in the lows) down the toilet… the latter being especially bad in the highs.
Then there's the issue that it takes almost 60ft to produce an undistorted 20hz waveform to begin with – hence the reason the neighbors had no problems hearing deep bass. Putting a sub-bass driver on the opposite end of the club will definitely increase deep bass for those congregating near the front of the booth.
I assume you tested with pink noise, calibrated mic, and at different points in the room? After that, you can also use the F-M curve to spoof or cheat things a bit for the volumes you're going for.
Still, the data indicates it's deminishing returns for the most part to go much over 85dB peaking (rms should be at least 10dB lower... that sounds louder than you think, unless you've just been "exposed" to louder), not to mention the futile efforts to achieve low distortion at these ever-higher volumes. However, with the more gimmicky types of EDM (ahum... cough... dub step) permeating the scene that sort of need these newer sound systems that are being driven so hard, it's a self-perpetuating feed-back (metaphorically speaking) cycle at this point.
Last edited by Reticuli : 01-07-2013 at 06:22 PM.