making a dead room is more complicated than just throwing up some auralex all over the walls. You need bass trapping. If you just cover those walls with one inch thick eggcrate crap, you will be in trouble.
bass tends to gather in corners. You will want very thick trapping here. Check your local drywall/insulation suppliers for a product called owens corning 703 or 705 rigid fiberglass insulation. You might also want to look for rockwool. This traps very low frequencies much better than foam, so you will have a more even room, as opposed to a "bass hole".
This insulation is usually wrapped in fabric and put up on walls, to replace foam. Check out
http://realtraps.com/facts.htm for more info. Read it, it will help a ton.