My room (11x13) is furnished with only two chairs for listening and a set of shelves holding cds on one side. There is nothing else to remove/absorb/diffuse reflected sound.
First and most notable difference was a reduction of harshness with the addition of 4 inch thick panels at first reflection point. It cleared up the imaging and brought the soundstage into focus.
There is a 4 inch thick panel directly behind the listening position and I also use Aurelex bass traps in two of the corners which seemed to help tighten up the bass.
With these treatments I can turn the volume up much further than before without overloading the room.
