Auralex kits tent do be inefficient for bass control and will easily ruin your room high response. You want to ballance your room, not kill it.
I did a mix of RPG and hand made bass traps.
The RPG kit uses a different kind of foam, that works as a membrane, having better mid bass responses.
I also did several bass traps. Check Ethan Winer's forums, where he explains how to do a fiberglass/rockwool based bass trap.