Soundproofing

Folkfreak knows of what he speaks. His room is the best constructed I have ever been in, and is proof of the effectiveness of the ASC Wall Damp constrained layer damping product. I rapped on one of the walls in his room, and the sound produced was that of knocking on a thick piece of slate or a brick---a non-resonant click.

I bought some pieces of Wall Damp (it is sold in 4" squares), and put them between the two shelves (I bought extras, to double the thickness of each top shelf to handle the weight of my heavy turntables) I have on top of each of my Solid Steel racks. A cheap and effective upgrade!

The op is asking about soundproofing materials, and for the space between the joists and behind the new ceiling I would 2nd the suggestion of Roxul Safe ’n’ Sound (instead of the more common fiberglass insulation such as Corning 703). Using the ASC isolation "channeling", to which the new sheet rock is attached instead of to the studs, will decrease the transmission of sound to the room above.

Applying the ASC Wall Damp to that sheetrock, with a second layer of sr on top of that, will decrease the walls ability to do what drum heads do when struck with a drum stick---move in and out in the middle, which is how they create sound. Sheetrock actually flexes between the locations where it is screwed down, the middle moving in and out, creating noise. Folkfreaks’s room exhibiting none of that---the room was very quiet. Not just in it’s isolation from the outside world, but in the sense of it not creating any sound of its own. The quietest room I’ve ever not heard ;-) .