If this is indeed caused by room interaction (most likely) you could try to narrow down the frequencies that are resonating. I have found the Stereophile Test CD or Test CD 2 useful for this purpose. These disks have test tones set a specific frequencies, allowing me to narrow down a resonance problem and immediately tell if a change in speaker placement has helped. It is quite obvious when you listen to the different test tones which one is causing the problem.
In my room with my current speaker placement I get a problem with the 40Hz tone. When I play music that has energy in this area, this part of the bass response is emphasized way out of proportion to the point that it is nearly unbearable to listen to some songs.
In my room with my current speaker placement I get a problem with the 40Hz tone. When I play music that has energy in this area, this part of the bass response is emphasized way out of proportion to the point that it is nearly unbearable to listen to some songs.