Every room is different as far as dimensions, size, etc... One good practice is to make sure the distance from the front wall to the driver on the speaker is different than the distance from the side walls to the driver center. If you are limited on room size, experiment to see what sounds better. The closer you have it to the front wall, the more bass enhancement you might get. I would suggest trying to leave 2-4" min if possible. My M80's are about 6" off the wall.

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85