Like ghdprentice said:
"Your best bet is speaker placement. Moving the speakers back and forth from the wall, and your listening position"
You may be sitting in a null point where the bass is cancelling out. Have you tried moving your listening position? In my room I have two listening spots. The first is in the sweet spot - almost equilateral triangle. Bass is good - tight, punchy and faster. The second is about 4 feet further back at my drawing table. Still sounds good but the bass is just a little overbearing on some tracks. Actually works out pretty well because I usually sit at my drawing table at night and listen while I work. The additional bass oomph works well at lower nighttime volumes. Like a built in loudness button!
Pulling the speakers any farther out into the room might lean them out a bit more. But it might change the bass nodes also. You have to experiment with positioning first - both the speakers and your seat. Or, maybe you've done that already?