Does soundproofing improve or harm sound?

G, Mass, in the four walls as well as 5/8 sheetrock will make an audible improvement. Cross Fur the ceiling AFTER sheetrock with RC and you will reduce or eliminate the ugly treatments later. Use 6inch accoustic insulation in 31/2 inch walls combined with the 5/8 board and you reduce the resonant freqency of the wall. These few extras will generate HUGE returns on money spent. Z.

Doug came pretty close, but hat and resilient are two different and mutually exclusive products! Hat channel is just for furring, RC decouples the sheetrock from the framing. You want RC. Sound board is also a great product,just make sure to cover it with 5/8. 1/2 rock moves too much and absorbs Bass energy. Go to a REAL supplier to order door frames in any width you desire in 1/16 inch increments. Walking into the new room SHOULD feel completely different. You should NOT need any ugly treatment(s) With stiff, decoupled, insulated walls and lid. Z.