Instead you should look at treating the room you have first, check out www.rivesaudio.com where you can plug in your room and find out where your problems are. I just bought their CARA software to model my small room and test setups before I buy treatments.
At my old place I made my square room sound better my system in much larger rooms without treatments.
At my old place I made my square room sound better my system in much larger rooms without treatments.