Styrofoam, rock wool, rigid fiberglass???

Ok so I'm having problems figuring out which material to use for acoustic treaments of my studio. I've heard a lot of people using rigid fiberglass covered with fabric, but rock wool is cheaper...does it work as well. Does styrofoam insulation work as well as the other two, does it even work at all? It seems like it would be easier to work with...cut, carry, you know. If somebody could offer me some insight i would really appreciate it. Thanks a lot Mike D.

Mike, > rock wool is cheaper...does it work as well < Yes, it's pretty much the same stuff. > Does styrofoam insulation work as well as the other two, does it even work at all? < No, styrofoam does not work at all. --Ethan