Added additional room treatments—specifically Alpha Series Diffusor/Absorber panels
4 inch thick for the side walls and 6 inch thick for the front wall just behind the speakers.  This complements the bass traps that I have surrounding me in the listening position. 
I was stunned with the sonic impact.  Resolution increased and everything snapped in to focus (kind of going from standard def to high def) and sound stage exploded in every direction, making the small room sound bigger than it actually is.  Right up there (or better) with any gear purchase to make music sound better in your rig..,or should I say equally as important?
[url] 
 F290E593-684A-456B-9C6A-6439AE26A6D5
F290E593-684A-456B-9C6A-6439AE26A6D5 by 
Tube Dad, on Flickr[/url]
[url] 
 244 Bass Traps- GIK
244 Bass Traps- GIK by 
Tube Dad, on Flickr[/url]