Have you scanned the room for frequency response at your listening position? This is a good way to see what is really going on before you start spending money. There is free software online to do this with a computer soundcard: RoomEQ Wizard
http://www.hometheatershack.com/roomeq/Moving the speakers out from the front wall from 3 feet to 4 feet really helped my overall sound too.
This changed the whole bass sound due to bass echoing off the front wall. Other frequencies benefited too. I thought my wife would yell, "BACK!" when she saw them farther into the living room, but she enjoys the system too.
Bryan P gave me good advice on another forum. And I didn't even know he was a true audiophile then... The GIK products he recommended are extremely powerful.
I also installed 8th Nerve Adapt which made the room sound great without losing any feel of openness or ambience. I have not yet measured the room again to know how well all this actually helped in the bass freqs, but they solved all of the problems that were bothering me. Not cheap, but it does work, I highly recommend Adapt stuff.
Rich