I'm adding a 850 sq ft room to the back of my house. The construction
guys have just finished framing the raised floor.

Since we will have practice and record in the room, I want to keep
sound from going in or out of the room.

I'm worried that the raised floor with 3 foot crawl space will act as a
speaker and drive my neighbors crazy.

Is it better to use 1 1/8 inch T&G plywood for the floor instead of the
standard 3/4 inch? should I insulate the floor by adding r14 between
the floor joists before the plywood gets installed?

Is it better to screw in the plywood instead of using nails?

Idea's for the walls?

Any info on this would be much appreciated.

Dan