If space permits, install surrounds 2-3 feet above viewers. This helps to minimize localization effects.
Aiming surrounds straight across the room, not down at viewers, helps create a more open, spacious surround soundfield. (Some models may require different aiming; see Special designs below).
Alternative Surround Placement
If rear wall mounting is the only choice, aim the speakers at each other (A), towards the front (B) or even towards the side walls (C, D). Experiment with placement until surround sounds seem to envelop you, rather than coming from behind you.
No adjacent walls
Surrounds can go on stands facing each other to approximate the preferred side wall mounting (A), or to the sides or rear of the viewing area aimed upwards. In the latter case, they can go right on the floor, or preferably, a few feet off the floor such as on endtables (B).
Side wall mounting, while preferred for direct radiating speakers (A), is usually required for surround speakers designed to radiate to both the front and rear (B). Check instructions for any special placement or aiming needs for your speakers.