Before I stupidly parted with my M60s, I had them in a 14' square bedroom. In that small space, the bass was absolutely fantastic. They didn't go super low in the larger HT room, but upstairs was a different story.
I'm guessing the M50s would also be pretty deep and rich in that small space the orig poster described.
OTOH, M3s (while likely requiring a sub for the deep bass) are very versatile and will always find use later on should he upgrade.
You can't have too many bookshelf speakers laying around, can you? But what to do with a house full of towers?
