The energy IS the problem. Especially when you have brightness sticking an icepick in your brain when someone hits a high note. If that's the case, which it is for me, nothing else matters. I've been listening to headphones. Redirecting energy would be good, but the cost or complexity of a project to build or buy diffusors to cover a large room would be rediculous. Too much bsorbtion makes the music dark and not worth listening to either. Room tunes (both brands) use the same technique as a lot of others. absorb, but have reflective a reflective serfice that will keep the high freq bouncing around. Will it help with brightness I don't know.
"Even though I'm sure they will be better than nothing, given the fact that manufacturers go through many prototypes with a wide variety of materials to finalize their designs it seems unlikely you will hit upon the most effective combination of materials and dimensions on your first try."
Some do - some don't. Obviously, if you see fiberglass or wool and a reflective surface, they didn't put a lot of R&D into it. That's all most acoustic treatment is. And given the price, I would assume they know that we know.
