Acoustic Panel Help

I would first put some sort of absorbent material back there, like the aforementioned blankets or even towels (temporarily) to see if lessening the reflective sound might be an actual improvement.  It sounds like your Maggies are pretty close to the wall if your TV is right there with them.  Planars or stats are usually happier farther out in the room.  Figuring that out could tell you what you put on the frames you're talking about building, hard, soft, or diffusing like Vicoustic. Putting some kind of tapestry up, you could just lift them to get to your cables.  Sounds like your electronics are below the screen.  

With the amount of toe in you have are the speakers even firing directly to each side of the tv to make any treatment effective? I also agree with the above posts that some absorption would be in order. Good luck! 

@audiodidact 

First thing first. What part of the sound are you trying to improve? Clarity, bass, soundstage, depth? That will tell us what direction to go.

I read somewhere that having a tv between your speakers is no worse than drywall or windows or wood. I’ve tried absorption covering the tv but it just sounded like the center image became diffuse, flat and dull. Uncovered sounds lively and open and no smearing of the image.

I have a bunch of GIK alpha panels and corner traps and some commercial wood diffuser. I’ve been moving them around the room for a few years and found that, in my room, a 2’ X 2’ diffuser behind each speaker (ear level) and absorption panels in the rear (of the room) and in a (wet) bar area of the room works best. The wet bar makes my room a fat “L” shape. I had a nasty bump between 80hz and 125hz. Loading up the bar area with absorption panels + corner traps solved the problem. Any absorption on the front wall sucks the life out of my Maggies and too much diffusion (front wall) makes it sound phasey and weird. I experimented with placement until I found what sounds “right” to my ears. BTW, my GIK Alpha panels are equipped with scatter plates and the corner traps have range limiter facias.

A hard reflecting surface, like your OLED screen centered between the speakers is not necessarily a bad thing.  This often actually helps to create a sense of focus or solidity of the center image.  You can try covering it up with something like a comforter to see if that helps; if it does not, don't worry about it.  You can also try diffusion on the rest of the wall behind the speaker, but that too may no be necessary.  There are commercial panels made by companies like GIK that may improve the sound and can be covered to your liking visually (including blowups of photos that you like), but before spending that kind of money, you could try othe decorative "treatments" like large potted plants (real or fake).

Good luck on your endeavors.