Diagrams on speaker placement

Here is a diagram from a website on speaker placement.

It's perfect, other than the fact that the subwoofer should really be in the corner for best results. You'll be surprised how much 'thump' you lose by not placing the subwoofer in the corner (any corner) of the room. Even regular speakers produce more lower frequencies when placed in corners of rooms.

You can view the website on surround sound speaker placement here.