Originally posted by: Peetoeng
There's additional rule in regard to speaker's location with respect to wall. They must at the same distance to side walls (if left speaker is 3 ft from left wall, right speaker should be in the same distance from the right wall). And their distance to the rear wall is a proportion (1/3, 2/3, darn it, don't remember it dude) to their distance to the side walls. If the speaker is rear-ported, you should adjust so that the low frequency doesn't sound boomy.
I just remember the site, go
here.