I had a same dilemma few months ago when I bought Def Tech 2500 center channel speaker. My HDTV was RCA Scenium and has very thin top TV space. My previous center channel speaker was Klipsch and was able to place on top of my TV with some modification but Def Tech 2500 was out of question. So after looking into some ready made to sit on top of my TV for center channel, I wasn't satisfied with the look and its stability. Finally I went to Home Depot to buy the regular metal shelf L brakets (fairly large size) and mounted to the rear wall and cut medium density MDF board to proper size and covered the board with exercise mat (one you place under the treadmill machine) using staple guns. Once it is nicely covered with mat, the board was resting against the metal L bracket extending all the way to top of my RCA RPTV Scenium. It is very stable and my Def Tech 2500 sits on top of the board sounding wonderfully ever since. Once I knew what I was going to do, it only took me couple of hours to do the whole project. Hope this will give you some ideas to solve your situation.