I was just re-reading the original post, and it seems as if perhaps, this person wants to raise his Center speaker higher. But higher creates the same problem as lower. The only real choices are below the TV or above the TV, and in either case, it doesn't place the speaker at ear level.
Some one in the group couldn't accommodate a center placed below the TV, so he made a bracket that mounted to the threaded wall mount holes in the back of the TV. In essence, creating shelf that sat just above the top of his TV to hold the Center speaker.
Again, the brackets supporting the shelf were bolted to the back of the TV where the wall mounting screws usually go.
Something like this requires some fabrication. I think he build his out of angle iron, though I would suspect it could all be done out of wood, and still be reasonably rigid.
So, in hind sight, I'm not 100% what the Original Poster is trying to accomplish. But, I think we have given him the only realistic solutions possible.
Steve/bluewizard