Our family room is a 20'x20'x20' cube that opens to the kitchen area with some windows near the corners. I have my Martin Logan Aerius i speakers along one of the 20' walls about 13' apart and the listening couch is about 12' away and the floor is covered with a large area rug on hardwood. Contrary to my expectation, I have no echo and the overall sound is very good. Interestingly, the large distance between the speakers to some extent makes up for the inherently narrow sweet spot of these speakers. You need carpet on the floor and the furniture typically does the rest.
