This is a little off-topic, but I thought everyone here would probably have some good insights. A friend of mine is setting up an amateur recording studio in his basement, and was looking to do some soundproofing for obvious reasons. I figure the materials needed to soundproof a studio are likely to be similar to those needed for a home theater, so here I am. Any suggestions? He's looking for general soundproofing as well as specific pipe and duct soundproofing. Thanks in advance!