What is the best positioning of 5.1 channel speakers to get the real complete sound effect?

Center Speaker: Directly ontop/under the television.

Front Left: Approximately four feet away from the center.

Front Right: Approximately four feet away from the center.

Rear Left: 10 to 12 feet back from front left.

Rear Right: 10 to 12 feet back from front right.

Subwoofer: Can be anywhere, but most effective in the front of the room near the tv set. 2 IN THE FRONT AND 2 IN THE BACK AND LET IT RIP!HAVE BASE IN FRONT OF YOU. I agree with SigEp84. But to achieve the maximum 'thump' from the sub woofer, place it on the floor... Hey there Danny.The size, shape, and construction of your room will have an effect on the sound you hear from your speakers.The best position for the two front main stereo speakers is to have them two to three feet away from all walls and corners,level with and on either side of a Widescreen TV.(if you have one)angled to your listening position with the tweeters at ear level.The center dialog speaker should (preferably) be the same as the two front speakers. It should be positioned exactly midway between the left and right speakers.(sometimes you get a clearer soundstage with the removal of the center speaker). Your seating arrangement should be in front of the back wall of your room,depending on how close you view your video.The two left and right rear speakers can either be mounted behind you where you sit or adjacent to you on the side walls.They should be level with your ears when seated.If they are mounted high up they should angle down to your ears.You can't go by the measurements suggested to you from another answerer because every room and placement of equipment is different. The Subwoofer is the hardest speaker to position for equal sound distribution. However try to avoid placing it in a corner (the corner forces the sound to become directional ,and the bass could become boomy) or up against a wall, or behind you as the sound will be disjointed and separated from the front. .A good Subwoofer should only play the lowest frequencies( the lowest two octaves below 80 HZ). A lot of wrong information is given out about Subwoofers such as : bass isn't directional ,you only need one subwoofer ,or you can put it anyware. Let's put the record strait : bass is directional in a room - the room causes it to be directional.So placement is important so that the bass blends with the rest of the music.The lowest frequencies can't develop in a small room because the length of the lowest cycles are longer than the room dimensions.What you hear are only half and quarter notes which bounce and resonate between parallel walls creating an unpleasant sound.But people don't care if its good or not ,they must have one.They are trying to change the laws of physics and acoustics.This will upset some people and will probably result in me getting some "thumbs down" to register their disapproval]