terrible bass response / unevenness problem.

im sure you all have experienced the problem i have here, but i need sugestions on how to tame the uneven bass response in my room, the bass in my room is just terrible. im already going to change subs from a 12" to a 10" sub. (room is 12 X 13)

the problem is mainly with the low bass frequencies, at cretain low frequencies, the level of the bass rises dramatically and resonates the whole room. terrible air shaking feeling. then as soon as the bass guitar in the music jumps up to a higher note, the sound is suddenly cleaner and the level goes back to normal. i want to find a way so that all frequencies are being heard at the same loudness,(and felt at the same intensity). the bass with my sub is also lacking any detail(integration problem?),. is dull and muffeled. i already tried moving my subwoofer from the front right corner of the room to the left front corner, which made a fairly significant improvement in the bass resonating/uneveness problem.

i was thinking of getting an equalizer, but im not sure of a good one to use for a home stereo setup. all the ones i see seem to be rack mount units. i know more bands are better, like 30 or so. i know they say that you should try to fix the problem another way, before going to an equalizer, but wouldnt an eq be cheaper than thousands of $$ worth of sound absorbant panels, bass traps, etc?.

ideas anyone??

chad