[jhbrandt]

Redhouse,

Putting ply between the 2 pieces of rigid fiberglass is not going to do much for isolation. You would be better off building the frame like you are, but with 1/8" luan on the outside for shear. If you are set on using the 2" material, you can increase absorption by spacing it out from the back (luan) panel by 2" and almost get the absorption of 4" material.

Velcro is a great idea and has worked very well for other gobos like this. But nothing with eliminate standing waves except moving walls... - just don't get too close to the corners or walls of the room and you should be ok.

Isolation is another thing. You need a sealed room for that. This setup will attenuate outside sound somewhat, but it will absolutely not isolate you.

- John