Got mine above the A/V cabinet angled down toward the listening area. Had the wife increase the angle until in sounded the best and put a couple of those rubber door wedges/stoppers so it wouldn't move. They are cheap and works great.
I'd have to disagree. Even though I have my center on top of my TV right now (girlfriend won't let me put it below for the time being) I tried it below and I noticed a much greater sense of clarity to the sound. There was a thread from someone else who came to the same conclusion just a few days ago.
In addition to the other thoughts, it's also worth keeping in mind that for the best blend with your left and right mains (for more seemless sound pans), try to keep the all of the tweeters as close to the same level as possible. Nothing can sound stranger than the sound starting on one side or the other and jumping up or down as it passes thru the center...
As long as I used my TV, I always had the centre speaker on top (which was vertically closest to the level of our heads anyway).
Ever since I have a screen (100"), I have it below (or else the sound would come fro the sky, so to speak ).
Note that it isn't that critical, because the sound will rather likely be projected to the proper spot on the screen (i.e. the mouth of the apparent speaker). But I would suggest the above rule: above or below so it will be closest as possible to the height of your head.
And point it so, that it slightly overcompensates a possible error (i.e.: if it's below the screen, point it slightly above your ears, if above, slightly below). Use the empirical method .
it all comes down to what you prefer. I like mine below as I like the front speakers seperated from it than being close together. its all in what you like. do a test like some mentioned. the majority says above but I dont get why. I didnt like it there and like it below.
I built my cabinet with the center below a 36" TV. I think it comes down to looks. If I put it on top of the TV it would be just as far from the centerline of the main tweeters as it is on the bottom. I have had the center on top in the past and have not noticed any sound quality issues that make me want to put it back up again. One other thing, if you are going to put it in a shelf build it so that you can stuff the void around the speaker with foam to eliminate the cavity effect. Otherwise, top or bottom it won't sound as good.
I moved my center channel from on top of the TV, angled-down, to a stand in front of the TV, angled-up, about 2 months ago.
Huge improvement for my setup. Voices are clearer and appear to be coming from the appropriate place. I'm not getting the resonances from the TV cabinet. In all ways, it was a significant improvement.
I'm using a Wood Technology stand. They come in 12", 18", and 22" varieties and are already angled up. I thought I'd have to increase the angle a bit, but it's actually aimed perfectly, as-is. I'd prefer a stand with more mass, but I got this one for about $50-60, and wasn't sure if I'd like the placement. I do most definitely like the placement, but I may well upgrade to a heavier stand in the future.