So my TV speakers point backwards toward the wall, somewhat muffling them. I needed a way to direct the sound from the rear-facing speakers to the front of the TV towards the viewers. Here is my solution.
Best of all, it doesn't require any support. It even has small screw holes for very small screws (5mm long or so, just long enough to penetrate the back of the TV but not hit any electronics inside) to mount over the 85mm speakers. The holes in the plastic back of the TV were pre-drilled. I painted them gloss black to match the TV.
Problem solved, and they sound great after a little equalizer adjustment, too!
The only improvement I may attempt in the future would be to make it double walled like an insulated cup for further reduction of rear sound loss. But I'm pretty happy with it so far.