I've just got done building a 7x7 shed in my garage that I want to use as a vocal booth.
It's a plastic double-walled shed (really a single wall with an air space within the wall) with well sealing doors and a pitched roof.
Due to available space, I can't do much with the outside of the shed - I think that the improvements will have to be within the shed.
I placed the shed on some rubberized matting to reduce low-frequency vibration from the concrete garage floor.
I still get a fair amount of transmission from outside, even with the garage doors and shed doors closed, so I'd like to do some sound proofing as well as some room treatment.
For sound proofing, my first thought would be to screw some 1x2 wooden runners to the walls and hang drywall or Owens-Corning 703 (I looked at QuietRock and I don't feel that the benefit is worth the additional expense). I've seen lots of posts discussing the use of hat-channel and green-glue - would there be a benefit in using these options?
I'm also concerned that because the existing walls are plastic, I can't really 'hang' drywall - it would probably have to sit on the plastic floor of the shed - any thoughts here?
I also have the ceiling to worry about. Suggestions?
I'm concerned about the transition from floor to wall, and wall to ceiling - do I need something like green glue here?
Regarding room treatments, I know that I'll need to look at bass traps in at least two of the corners because it's a square room - I'm considering Auralex (or something similar) to treat some of the surfaces and perhaps the ceiling (at least partially). I think I might go with a couple of moving blankets in front of the doors. I have also draped a large comforter on the top of the shed roof to cut down on some of the higher-frequency noise coming from above.
I'd be grateful for any advice/assistance please. I have a limited budget but I'm determined to do it as properly as I can. Thanks in advance!