Eldwynn, hope Alan will fill in again, but I just don't get this entire "bass trap" concept. You know, bass sounds have very long wavelengths -- ~5ft @ 200Hz, 10ft @ 100Hz, 20ft @ 50Hz, and so on... Basic physics textbooks will tell you that waves in general just do not "see" an object that is much smaller than the wavelength. In other words, there is NO physical basis whatsoever for a sound wave of 10ft wavelength to be affected in any way by those bass traps of mere 1ft or smaller in lateral dimensions.
I strongly suspect that "bass traps" are yet another bunch of audiophile snake oils.