Ok...I am seeking any experience with bass from 43XX cabs. I have a room that is 12' 3 across and 27' long. There is a jog in the room at about 16 feet which cuts off about 3 feet of the width of the back wall. I have experimented with my listening position from anywhere from 12' to 15' feet from speakers. My speakers have been moved around too...and I have found the best spot so far is about 7'8" apart. I have noticed that I have nodes of lower bass, but the upper bass frequencies are not detectable at all?? Any ideas on how to solve this issue?

Here is a drawing of the room...the brick mantle is treated with a dampening material. Speakers are sitting on top of granitel slabs..3 inches thick. I know the room is a stereo nightmare, but its all I got for now and any help is appreciated.