basic room acoustics question

I'm sure this has probably been covered a zillion times, but I need a quick primer on dealing with some bass issues. Large bedroom, approx 30x15, one half bed/furniture, boring stuff, other half hangout/listening area. Concrete floor, framed/drywalled with concrete foundation walls, basically a basement. Currently have old set of nht 1.3 running on decent equipment with no eq or boosting/cutting-just flat. Speakers sit on stands along one 15 foot wall, about a foot out from back and side walls-so, here's the problem:Everythings great accept for bass. The nht's play reasonably low, somewhere in the high 40's/low 50's-in the listening position or moving left or right, bass is sorta muddy/too much mid bassy murky stuff. Move back about 6 feet and bam!-nice, deep, clearly defined bass, however, I can't float the sofa over the foot of my bed-my wifey probably wouldn't like that. Would turning the entire listening portion of the room 90 degrees possibly address this issue?I've moved the speakers many times in every direction, but none of it really effects any of the bass issues I'm having. Any one have some education or advice?-greatly appreciated!