Positioning is by far the best initial solution. Room treatment will help some, especially at first reflection points with decent treatments (i.e. not just acoustic foam, some decent fiberglass-based panels with a good thickness to absorb low frequencies). Bass is the hardest to tame in a smaller/mid-sized room, even with good bass trapping in the corners. However, coming from someone who went through 3 different sets of speakers and multiple component changes trying to "fix" the sound in my room, let me emphasize that you simply can't escape the limitations of your room without resorting to digital room correction. I'm using a miniDSP Dirac module between my preamp and power amp along with a decent amount of room treatment from GIK Acoustics (who are local to us, btw), and after taking measurements and letting Dirac do its thing, the results are nothing short of shocking. The biggest difference was in how much it evened out the bass response with all the modes and nulls in my room, which is probably what you're dealing with. If you want, since I'm in Atlanta as well (I go by Spamateur over at Head-Fi, and I know we've PM'ed before about headphone-related things) I can bring by my miniDSP DDRC-24 or DDRC-22A and the measurement microphone so you can see the differences for yourself if you'd like. Coming from the headphone world, I had no idea how much room interactions can screw up the sound of a good 2-channel setup, but Dirac saved my sanity and my wallet.