The key to center speaker placement is to have the tweeters in line with the tweeters of your front L-R speakers. If you look at my system pic in my profile you can see I have the CC resting on the top of my rack. To get it inline with the L-R speakers I used a pair of Isoacoustic stands which includes 4 inch risers if you want to adjust their height. It also allows you to tilt the speakers if you want to aim it.
