[Tonto Yoder]

Seems oriented more towards commercial installations, but info may be interesting, esp. for someone building a room from the floor up.
http://www.quietsolution.com/construction_solutions.html



There are several downloadable articles that might be helpful (even if one didn't buy the company's specific products).

[ctviggen]

When I was going research on room construction, I saw that these techniques were what was being used.  If you have the room, the double wall with the air gap would be great (although you'd really have to do the ceiling in the same way -- and don't forget the doors into the place).  Luckily, being single and on 3.5 acres, where my nearest neighbor is far away, I don't have to worry too much (for now, anyway) about STCs.

Thanks for the link!