Beheme,
As some of the above post indicate, the biggest problem is your room size and the not speakers. My room is slightly bigger than yours 12 x 15 feet. I have the Hyperion 938s that may be the answer to what you're looking for, but it took some time to fix the room issues. Now I'm satisfied. It will require some sort of bass traps (thick couches or audiphile bass traps and some sort of tweaking to the speakers with proper isolation footers, etc). The Hyperions have very quick bass to begin with so my work was made easier. I would try to stay away from most tube equipment as the tube bass will exarbate this problem. I know some will say some tube equipment do not have this problem, but every single tube equipment I have ever heard have had a characteristic tube bass sound, some less than others, but to my ears always present. Also consider the VS VR4jrs, not exactly to my taste but many seem to like their sound especially the bass.
As some of the above post indicate, the biggest problem is your room size and the not speakers. My room is slightly bigger than yours 12 x 15 feet. I have the Hyperion 938s that may be the answer to what you're looking for, but it took some time to fix the room issues. Now I'm satisfied. It will require some sort of bass traps (thick couches or audiphile bass traps and some sort of tweaking to the speakers with proper isolation footers, etc). The Hyperions have very quick bass to begin with so my work was made easier. I would try to stay away from most tube equipment as the tube bass will exarbate this problem. I know some will say some tube equipment do not have this problem, but every single tube equipment I have ever heard have had a characteristic tube bass sound, some less than others, but to my ears always present. Also consider the VS VR4jrs, not exactly to my taste but many seem to like their sound especially the bass.