Just wanted to share my experience on center speaker placement.

The top of my TV is 5 ft tall while our listening position based on our seating is around 3.5 feet. The center speaker is level on top of the TV. The sounds seem muffled and hollow. I checked my connections and they are all proper and tight. Increasing the sound level by 1 to 2 db did not change anything. I decided to tilt the center speaker forward such that the drivers are aimed at the listening positions. This corrected the hollow and muffled sound.

FYI

Pinoy

I had noticed the same as you.

If the VP150 is below the listening level, it sounds muffled. However, above the listening level, it doesn't sound half as bad. It is always best to angle it toward the listening area. I used pucks, they worked very well.

Pucks? You can sure tell this is a Canadian messageboard! :P