They sound great in small rooms and in large rooms, not hard to set up at all, but you are limited with placement in smallish rooms as the M80s are 19" deep so they can take up a fair bit of floor space. You can place the M80s as close as 2-3" away from the rear wall without affecting their performance too much, bass gets a little boomy on ocassion depending on the source material.
I think mine sound even better now than they did in my smallish basement at my old house. That basement was 2 'L' shapes joined together and they were about 12 x 16 and slightly less than 8ft high each. My current room is very open 20 x 15, high vaulted ceilings and open to both my kids' rooms which are 15 x 11 each and also open to my exercise room 12 x 13. My room is located right beside an open stair area to the main floor which is also open concept and 1000sqft. I have lots of air to fill and this open space has improved upon an already great sound I had with my smaller space I had the M80's in originally. YMMV.
