Large rehearsal/performance room analysis

[pitchtwit]

I'm doing a project on a room at a college I work at which is used for rehearing and performing - classical, jazz and rock/pop. It's my main project for my IoA Post Grad course.

Actions that I've arrived at for the room are: -

A. Identifying a relevant target reverberation time
B. Reducing the level and directivity of the drums
C. Creating a level room reverberation response
D. Reducing the large resonance at 88 Hz
E. Ensuring adequate elevation of sound sources

Because the multipurpose nature of the room, A will not be a simple answer. For B I was planning on just suggesting the installation of a drum booth. For E there just needs to be a proper stage installed, or the one that is used needs to be raised.

C and D will require some sort of low frequency treatment, but the interesting thing is that the front wall, which is huge, is one of those false walls that sometimes gets installed just in front of the real wall - at a slight angle - presumably starting off almost touching the real wall, and slowly moving away to about 1-2 ft at the far end. I would have thought that a panel absorber of that size, that's variable, would have been enough to deal with any low frequency standing waves in the room, but it's clearly not.

What I'm trying to find out is whether the false wall/panel absorber is functioning as it should, and if not then how do I find out about it. The false wall will no doubt be supported at various points - would this impede it's function? If there isn't porous absorption behind it, should there be? Should there be regularly spaced holes over the surface of the false wall?

I've considered various absorbers to deal with the low frequency problem, but the main problem I see is that because the room is large (13.64x8.11x6.24 m) the amount of absorption will need to cover a significant area - so blocks in corners won't be enough. Even if the absorption coefficient is great - it can only absorb sound that hits it right? I'm thinking of maybe suggesting that the false wall idea that has been installed on the front wall is also installed on the rear wall.

Any help would be greatly appreciated.

[pitchtwit]

Here are the plans for the room. It is Rehearsal Room 3 in the far bottom left of each plan.