I live in a house where my living room wall is right up against my neighbors wall (very common in Sam Francisco). I would like to make my living room wall a little more sound proof so I won't bug my neighbor and currently the wall only has plywood. I read somewhere that adding a piece of drywall over it will help. Any truth to it?
on a project and it worked very well. It is basically a panel that is assembled at the factory with a layer of material similar to the Green Glue that gregzoll mentions sandwiched between 2 sheets of drywall. Finished thickness is 5/8.