help me sound proof my dorm room

Yo Chet,
You might try using half inch thick fiberglass insulation with foil on one side. Spread a thick layer roofing mastic on the fiberglass side and cover it with a burlap or cotton duck cloth. These come in 4 x 8 sheets and the cloth will come in 60" wide bolts. Buy about 3 yards for each 4x8 and finish nail or double stick tape them foil side to the wall. It should reduce the bass at least 6db (75%) in the neighbors room. If you have any money left glue the 3/8" cork on to the foil side of the fiberglass. If you can't afford to cover the whole sheet with cork, use strips every foot or so to keep the fiberglass panel off the wall. The fiberglass panels should run about $12 each from an insultion distributor the cloth about $3-$5 yd. at Wal Mart and the mastic about $20 for a 5 gallon bucket at Home Depot. You can cut the fiberglass panels with a razor knife to fit around objects on the wall. The only trouble will be that your neighbors above and below will probably complain when you start cranking it up.

My older wood frame house sits above a 3 foot crawl space, and I was getting too much sympathetic bass vibration. So, about 6 months ago, I built several baffles for use in my living room. I made the baffles by gluing several "Sonolead" panels to some sections of peg board. I further treated the panels by applying sheets of a constrained layer damping material called "DexDamp" (similar to DynaMat used in cars, but better IMO). All of the materials I bought came from a marine supply company in Seattle called HamiltonJet. They ship worldwide, and you can mailorder from them. You might also find a marine supply store closer to you. I suggest you look at their Web site to explore the various acoustic treatment and damping materials they have. The Web site URL is: www.hamiltonjet.com

Thanks for the suggestions. In response to Avguygeorge, the speakers are on spikes on a tile floor. They indent just a bit into the tiling. The wall is about 12 inches from the back of the speakers and is made of cinder blocks. The left speaker is 6 inches from a heater/wall that faces outdoors. For some reason (who knows what's under the tile), neither of my neighbors above or below ever hears a thing, so that shouldn't be a problem. I think i will look into a fiberglass sheet that I can hide behind a tapestry. Thanks again
Tom