For my vocal booth, I used 2 layers of 5/8 inch sheet rock, with pink fiberglass insulation in between. Then on the inside, I stapled itchy pink fiberglass bats covering the walls and cieling, itchy side out. then covered them with cloth. for the door I used a double layer exterior door that was left over after a bit of remodeling I did. on the floor, I put two layers of carpet padding, and then a scrap of carpet over the top. Its really dead in there now, and fairly well insulated. On the door fram, I used a outdoor door frame(the kind with the rubber insulation strip pre-installed), and an exterior threshold(the kind with the half round squishy rubber seal. This lets the door close on the cords without hurting them, but still seals well.