I've looked into sound proofing material and it's expensive. I am constucting a home theater in the basement and want to get the acuostics right. two walls will be concrete with 2x4 studs 1 wall will be 2x6 the remainder 2x4.the ceiling are exposed floor joist now. I have not installed any insulation yet. Is ther a good cheap alternative to expencive sound proofing material that I can get at lets say, home depot? Like roofing paper? Thanks