On my older RPTV, I had my CS on top and found the sound to be nice. No complaints. When I bought out new DLP, I built a stand for the TV and incorporated the CS into the stand (built a shelf for it

) and I can not tell you how much better it sounds down there. It was a night and day difference.
I attached a picture of it. It's not the best picture, but you get the idea. Granted, the speaker is less than 6 inches off the ground, but the TV is less than 20 inches. I tried putting it on the second shelf and I found I liked the bottom shelf better for sound.