For what it's worth, I have Theater 4's in a 4m x 6m room but set up along the long wall. they sound good. I'd be a little concerned that in a more square room you might have some standing wave issues and with the speakers closer to the corners you might have too much bass. I think Wayne Parham may probably want to comment here. Again FWIW, I'm helping a friend build a pair of 2 Pi's and will post some comments on how they turn out and sound in my system (Bottlehead Foreplay and Paramours).

Garland