Quote Originally Posted by ChrisEPIC View Post
the problem is though, outside.
its not really really loud. but he lives downtown duluth, and the speakers are next to the wall so it rattles the outside and you can kinda hear it
Sounds to me like you just need to treat the room with some bass traps in the corners...

Just a side note; When sound proofing, an alternative to MASS is DENSITY, I use CLOSED CELL FOAM (armaflex, sprayfoam) daily (industrial sector) for this purpose.