John Sayers' Recording Studio Design Forum Archive

Tony,

You can't directly compare published absorption specs to performance in a small room, because those specs were recorded in a reverberation chamber. In a reverberation chamber, sound stikes the test material from random direction, but in a small room in the modal region, sound is striking the material from only one direction. In my experience, 2" 703 across the corners is effective on modes above 100 Hz; below that, its effectiveness falls off sharply.

Thanks, that's exactly what I needed to know. Since one 2" layer isn't enough, I think I'm going to do two layers of 2" Roxul RHF 40 with roughly 8" of air space in between. It's for a rehearsal room that is: 20.8'L X 10.6W X 6.7'H.
I just want to tame the sound a bit since it will be hard to hear everything clearly. I'm putting in an order for two bundles of 10 2'X4'X2" panels, 6 of them going towards the bass traps, and the other 14 going on the walls with 2" spacers so they are not directly touching the drywall.

Thanks,

Tony

tonocus wrote: I think I'm going to do two layers of 2" Roxul RHF 40 with roughly 8" of air space in between.

Forget the space in between. Put both layers together.

Andre

forget any "space" (air space) at all stuff it with any insulation, mineral wool, fluffy pink, 703 scraps, etc