My belated Christmas present to myself arrived this afternoon. I've been wanting to treat the flatscreen on the front wall somehow without having to drape something thick and heavy over it every time I want to listen.
Enter a pair of GIK FreeStand Acoustic Panels ("gobos").
I tried them in three positions.
1. Directly in front of the flatscreen, parallel to it, the two pushed together. Not much difference, strangely enough.
2. Perpendicular to the front wall, the rear of the panel touching the front wall, and snugged up against the outer edges of the flatscreen. This worked well: deeper soundstage and a little better tonalities.
3. Angled-- like so \ /--about half way between the inner rear corner of the speakers and the edge of the flatscreen, the rear of the panel perhaps 9" from the front wall. Effect similar to #2, but marginally more of the same improvements. This is where they're staying. They don't block any of the screen for viewing, so I don't have to move them back and forth.
Once again, thank you GIK, your products work!