Thought I’d expand on my thinking on center size. A center is used to anchor sound to the center of your screen. It’s only needed on larger screens when the center action doesn’t seem to come from the center for all listeners (which is dependent on the sweet spot size and seating distance v.s. screen size). In this case a large speaker (wider) relative to the screen may not work as well as a smaller one. On a personal note, I prefer virtual centers when I can get away with them.

Since we are talking about on screen sound placement … the main speakers should be as close to the screen as possible to keep the sound stage on the screen. It’s just weird when a on screen action comes from someplace else..