[Housteau]

Thank you.  Using these screens was the easiest approach I could think of.  It took a lot more time and effort to build some of my other more conventional treatments.  These screens can be bought as a quad as well.  They would be ideal used as a pair to conceal corner treatments.  Instead of cutting the 703 into triangles as I did, you could make cubes which I now understand works better than the triangles.

[ctviggen]

I already have 6" thick OC703 panels floor-to-ceiling in the corners and 6" OC 703 panels behind the speakers.

Rectangle rooms have 12 corners, not only four. The more total corner surface you treat, the flatter and tighter the response will be. It's that simple. The front and rear walls are also good locations for more bass trapping. Though you don't have to go nuts like I did with 51 panels (so far) in my living room.

--Ethan

And you sit, where? 

By the way, any recommendations for treating a beam that runs the width of the room and penetrates about a foot into the room?  I'm concerned about the right and left speakers and center channel reflecting sound off the beam.  Do you treat the beam or the first reflection point (on the ceiling) for the speakers?

[syntheticwave]

The main problem is the system approach. When the system ends by the loudspeakers we cannot reach true spatial audio, because the most problems arise, if the loudspeakers have done its work. Only possible solution of this problem is described on
holophony.net

[Ethan Winer]

And you sit, where? 

On my backside.

By the way, any recommendations for treating a beam that runs the width of the room and penetrates about a foot into the room?

Small things don't matter much acoustically. Unless the beam is directly in the line of fire, and the reflections would also go right toward you, it's probably not an issue. If you're determined to fix it anyway, I'd line the front face with absorption.

--Ethan