speakers efficiency

Duke,

You seam to know a bit about pro audio as well. Do you have any information on absorptive properties of crowds and rooms with large volume? I know that Master Handbook has some info on this but I have misplaced my copy.

Thanks!

THX = to be THX certified, equipment must meet certain standards such as sustained volume at 110db.
Ultra THX is even harder with 112db.
Many amps/speakers can't handle these loads. If your audio gear can produce 112db continuous, it means that you can play very loud, distortion free music.
My best amps aren't THX certified even though they can blow away the criteria (keep that in mind). 120 watt tube monoblocks into 94 db speakers.

Bignerd, I don't really have any experience in pro-sound applications; I just have played around some (maybe too much) with prosound drivers.

I have no specific knowledge of the effect of a crowd on room acoustics. I'd guess a crowd of people would be more absorptive than diffusive, such that the power requirement to meet a given SPL in a full auditorium would be several dB more than if the room was empty. And since most absorbers are more effective at short wavelengths (high frequencies) than at long wavelengths (low frequencies), the spectral balance of the soundfield would be tilted downward somewhat by adding a crowd of people. But I have no idea of the specifics of such effects.

Duke