Flat screen between speakers, again.

I know this has been discussed before, but after reading most of the somewhat recent responses to similar questions I still need to pick your collective brains.
To mitigate the TV's impact, I am considering building a panel that would cover the TV when it's not in use. The panel would be a 2.5' x 4.5' diffuser or absorber. Ideally it will hang above the TV when I am watching TV and would lower down to block the TV when I am listening to music.

My question is whether this is a viable solution and, if it is, would I be better served with diffusion or absorption?

Funny you should say that. I read somewhere recently that leaving it alone is fine and in fact, that it sounds better with a TV in the space.

Well that would certainly save me money and effort, but I do believe that the additional room treatment would improve my situation, rather than maintaining the status quo. Thanks.

Have you experimented yet by covering the TV? Before you build anything, try using a bath towel or lightweight blanket over the TV. This will not cause very much absorbion, it just eliminates the reflective surface between the speakers.

I’ve recently researched this subject. It seems a lot of people with elaborate solutions eventually end up leaving it off permanently.

I just replaced my TV and had the wall bare for a few days. I did notice a slight improvement in soundstage stage depth. I’ve decided to try treating the rest of my room first and only then revisiting the TV situation. I did get a mic and run some baseline sweeps for frequency response and reverberation time.

Diffusion is usually heavier, especially a skyline type that is deep enough to have a wide effective frequency range. You might need a counterweight system or risk damaging your screen. Full coverage of the screen may not be necessary either. I may experiment with some 2’x4’ panels and listen. It should be easy to hang them even with 6” spacers so they clear the TV. Depending on your room layout a set of heavy movie theater type curtains might be an option.

I’m not yet convinced it’s necessary in all situations. Only you’ll know if the juice is worth the squeeze.
And I forgot the obvious one. All things considered it might be best to treat the room first, and then get a motorized TV lift cabinet. 
More of a visual thing.  Close your eyes when listening.  Hearing is improved without visual interference.
@tony1954  Try a test with a sheet of Owens Corning 703 fiberglass board and see what you think.
Perhaps a 5 sided box with absorption on one side and diffusion on the other side that could slip over the tv might work? Just be mindful of the cabling.
Perhaps a 5 sided box with absorption on one side and diffusion on the other side that could slip over the tv might work? The inside could be lined with microfiber. Just be mindful of the cabling.
Long ago way before the projection screen that mounts on the wall I had a TV. I mean a real vacuum tube TV. As thick as it was wide, which wasn't much, only 32" screen. Yet that was big enough to hear the improvement when covered with a thick blanket. Forget towel, THICK blanket. Think quilt.  

Forget diffuser, too heavy, cumbersome and expensive. What you want is absorption. A nice cheap and light, easy to move around panel.  

The stuff you want is called Owens Corning 703 acoustic panel. I would just get one, 1" thick will be plenty, and wrap it in some open weave (think speaker dust cover) fabric. 

Make something to hang it over the screen when listening, put it on top of the TV when watching. Easy peasy.
Thanks for everyone's responses. What I should add is that this is only one aspect of my diving into "room treatment". Whatever the final solution ends up being, I do think I would prefer exploring an actual room treatment option, as opposed to throwing a blanket over it.Now that the good weather is disappearing and I am not spending 4 or 5 days a week at the golf course, perhaps I will finally get off my butt and get things fixed. One Covid byproduct is more time on my hands.
two thoughts ,
sound absorbing curtains that cover tv when not it use.
or sound absorbing panels by I think ATS makes a clip that mounts to back of panel and the female part mounts to Wall and slides down into it . make a lightweight backer to push panel off wall whatever the tv is 4"? and mount that to panel grab the panels 24 x36 or 48 " or custom and side them down into slots and they would hang in front of tv covering it .( they may flex a little because they would be hanging but done right they would be fine . I use the panels in my dedicated room , if you pm me I can send you a pick and a scribble of what im saying 
My neighbor had a carpenter fit a cabinet to his high ceiling with a motorized carriage that takes the tv into the cabinet when not in use.  
Dependent on the speaker type (dipole etc.) and the rest of the room.As usual the answer is unknown until you try.
Sure, but heavy curtains work fine too. While shopping, put your ear up to them, and you’ll hear the better one’s.

Also, push the panel as far back as you can. If there’s any room behind it, like say 6" or more, you would not be wrong to treat that space with a thick panel.

Also, consider the floor between behind the speakers. I find high frequency hash lives there for some reason. If you want to experiment by throwing some blankets or pillows over the TV, and on the floor you’ll gain first hand knowledge inexpensively about your potential benefits and rewards.
Take a dowel rod, or even a 2X2 board about the width of the TV. Drape a comforter or thick blanket over the dowel. Drop the dowel over the top edge of the TV so the comforter covers the TV. If you like the results, tidy it up and make it a permanent device to use when listening, or just know that a more permanent solution would be worth your efforts. 
Tony, I recommended a blanket as an experiment to see what if any sonic change occurs vs. the TV glass.

In my case, I was very satisfied with the sound from my system but wanted to see if eliminating reflections off the TV would be beneficial. I tried absorbion and it changed the imaging. So I tried a light blanket and I heard a more focused 3D image; it's like the TV disappeared. 
Now I use a the cotton blanket cut to size as my treatment.

What colour blanket? (Just kidding.)
I have a comforter I can try, but I also have several 1' x 4' cheap foam absorption panels that are quite light. Perhaps I can attach them to a thin 4' x 5' panel and hang that on the TV with padded hooks. The only risk is damaging the TV screen, which would really suck.

I have a pair of the GIK free-standing panels, 4' x 2'.  This allows you to experiment with placement.  I started off with the pair cosied together directly in front of the screen and as close to it as possible.  But I ended up with them separated, at 45 degrees to screen, half way between two side edges of screen and back corners of speakers.  Moral of the story: the most obvious place for acoustic treatment may not be the most effective.
My TV/DVD(no cable, just over the air) is on a roll away. Wanna watch?  Roll it out of the closet, 2 minute hookup to the system for movie night. Otherwise, 1 minute to just get in the space between the speakers to just watch the tube.

TV in  the living room is an eyesore. Bad enough the system takes up space, but I carefully selected pieces that also are easy on the eyes!

I would experiment between damping and diffusing. No one here is in your room.
a lot of good ideas to try listed above. I did something similar by making a "slip cover" for the tv made from heavy fleece and acoustic foam. Basically it is a big pocket. Very simple to make and I do not sew for a living:>)   *does it make a difference?...in my case, I think it did tame the hard reflective surface while maintaining image focus and 3 dimensional soundstage. YMMV!
I had good results using absorbers placed inside of and slightly behind the speakers - between the speakers and the TV. These absorbed some of the sound coming off the sides of the speaker before it could hit the TV screen directly. I perceived better soundstage depth and could still watch tv with the treatment in place.
put the flat screen on a wall bracket that you can angle up and down, when listening to music angle it up so reflections go above you. works really well in my system and very noticeable. another option is to get a comforter and make it into a cover that hangs on your tv then attach your fav absorber to it, again easy to remove and wont damage your tv. you only need to cut it down to size and add corner pockets like a triangle on the back side to hang it to the TV edges then by adding the lets say Gik panels for the freq absorption you need to the front. 
Just get a couple of ebay Styrofoam diffusers and place them in front of the screen. They weigh next to nothing. I place mine on the top edge of the TV resting against the wall when the TV is in use.
@tony1954 , I have tried out a couple things to cover a 55’’ flat screen, like a towel, pyramid foam, Artnovion Myron E and Quadratic diffuser.

The Quadratic diffuser I like the most. I did notice better separation, and a lot more energy and punch. With the Artnovion Myron E the sound was brighter and the separation wasn’t very good.

Before the tube amp shown in the picture I had a solid state amp in a little furniture. The furniture I used to put the diffuser on. But then I did upgrade to the tube amp. This was the moment when I had to come up with some structure to hold the diffuser. Couldn’t use the furniture anymore, because of the heat, size and weight of the amp.

The plan was to make a prototype and get it done right by a Carpenter later on. But then I was so happy with the amp, that my present speakers haven’t been up to task anymore. Therefore I did get the new speaker first and live a little bit longer with my provisional solution and let the carpenter a bit later.

That’s how it looks right now:
"Moral of the story: the most obvious place for acoustic treatment may not be the most effective."
You mean like finding out that the best place for your sub is in front of a doorway?
@greenhorn20 Thanks for the feedback and sharing part of your journey. Oddly enough, the picture you supplied looks very similar to what I imagined mine to look like when complete. I am currently building two short racks used 1.25" walnut shelves and 3/4" black pipe to hold them together. I currently have two identical acoustic panels placed similarly behind the speakers as well. After reading all the responses and suggestions, I am leaning towards putting the TV issue on hold until I have more seriously addressed my room treatment and added a bass array.

Funny thing is I actually have several cheap styrofoam absorption panels that I was going to experiment with.

I will definitely give the angling a try. I have a TV mount that allows for angling and of course it is currently set up to direct everything directly at my head.

cheap foam absorption panels that are quite light.
Never use pyramid foam. It sounds bad. I tried it and now it's stacked in the corner. 
Tony, assuming the TV is directly in the middle between the speakers and there is some space between the main speakers and the TV you do not have to do anything. The TV is inside the important first or early reflection points. You may want to put some absorption on either side of the TV and on the side walls. Most importantly is to make sure nothing in the TV rattles. That drives me nuts. 
Tony - where are the speakers located relative to the position of the screen? Is the Screen mounted on a wall?
I concur with mijostyn.
When I had my speakers on either side of my screen they were ~8" in front of the screen. Experimentation demonstrated to me that there was no change in sound quality when the screen was blanketed.Your situation may be different and some reasonable suggestions for experimentation have been given.In the end - if it ain't broke, don't fix it.
The other place I tried the GIK panels was perpendicular to the wall behind the TV (and hence also to the TV itself), with one side edge of the panel touching the wall, and snugged as close to the edges of the TV as possible.  This was more effective than panels sitting directly in front of screen and nearly as effective as 45 degree positioning described above.
The rear of my speakers are 22" in front of the TV and the speakers are spaced only slightly wider than the width of the screen.

The TV screen is angled slightly down to align with me when seated. Another member extolled the virtues of simply angling the screen upwards to direct any reflections towards the ceiling. He said that this simple solution yielded significant improvement.
I already have absorption panels behind the speakers and will be adding additional panels to the first reflection points when I figure out how to do it properly. One side is open to my dining area and the other side is a glass patio door.
I take the cushions off of my love seat and place the back cushion in front of the cabinet holding the tv and the bottom cushion in front of the screen. It covers the 55” screen very well and it is 4” dense foam. I don’t know for sure if it helps, but it draws attention away from my aluminum foil helmet.

Seriously, I do you use the cushions and it does tame the highs and improve the soundstage depth.
I guess it is just a sign of the times the lengths so many of us are willing to go to a) satisfy our sound fetish and b) watch television.

Unfortunately, my need for an aesthetically pleasing solution won't allow me to go the pillow route.

And, if you don't mind me asking. Which brand of aluminum foil do you feel provides the best RFI suppression?