The best speaker for a small room...at any price point.

The Wilson Beseech Discovery's would be my choice. Super fast and deep bass due to carbon fiber cabinet which nearly eliminates cabinet resonance. 

Kef ls 50 + a sub or two will be hard to better.  

Hi,

I also live in a small appartment, and always had issues with bass boom with ported speakers (Klischp, KEF Q900, KEF LS50), and then I bought ATC SCM 19.

ATC are the no-ported design, and can be kept very close to the wall. Mine are kept 3 inches from the front wall (with some absorption treatment), and there is absolutely no issues with bass at any volume. Obviously other components also play a very important role in tonality and how bass is managed.

Good luck

I'm currently listening to the ATC SCM 11s in my 11.5 x 12 room and while the sealed design has effectively addressed the bass boom issue, I would definitely recommend these speakers be mated to solid state gear.