sound proofing (deadening)

[Ltldrumboy]

http://homerecording.com/ubb/icons/icon5.gif
i am building a 7x8 room in my garage. that will be used as a drum practice room. ideas on materials to use? my idea on this was to "sandwich" homasote, insulation, homasote, 1/4 dead air and lastly a layer of drywall. what would be the reflection and absorption properties of this room. any input would be GREATLY appreciated!http://homerecording.com/ubb/icons/icon5.gif

[BigKahuna]

I wasn't familiar with homasote so I looked it up:
Homasote® board consists entirely of paper fibers converted from recycled wastepapers. Added to this are ingredients that give it the superior weather-resistant features for which Homasote® board has become so famous. The small amount of newsprint ink remaining through the processing gives the board its grayish tint.

Sounds like sound board to me ... but environmentally friendly
Actually the weather-resistent part makes it sound more like a house-wrap material, which would lead me to believe it's more dense material than sound board ... but I'm not sure about that.
Anyway ...
If you're looking for a good sound proofing solution, I think a different configuration for the walls will give a much better STC. For example, a staggered 2x4 stud wall with double 1/2" drywall on each side with insulation in between will give a STC rating of 53 ... which pretty good. Since drywall is pretty reflective, you could treat the room with a 1"-2" foam product on the walls to deaden and 3"-4" in the corners of the room (4' from the ceiling up to the corner) to avoid bass freq buildup.
If you're looking at just acoustic deadening ... I think just putting some fabric in a frame over the studs (so the sound waves can get to the insulation better) would give better absorption than just a layer of sound board all the way around. Either that or using foam as described above.
Good Luck!