A fake tree?

Do you have kids? It might be cool to build in a ledge about the height of the couch and make it a loungy area... or build some sort of secret play house area. I know my kid would go nuts back there.

Without seeing the other side of the room, and assuming you can’t flip the sofa so this niche becomes the TV space then I’d suggest wall to wall shelves like this

It will be a nightmare to dust so maybe the tree with an uplight for night shadow effect might be the way to go.

also.... does the arm of the sofa need to be up against the window wall? Or could you pull it away to create a walking path? And how deep is this space?

No kids lol. I was thinking shelves or bookcases but like you said it’s going to be such a pain to dust. I would prefer to keep the arm against the window since this keeps the couch centered with the tv.

The indentation is 4 feet deep and 8 feet wide.

would it be better to drywall it up and then add a door on the other side to create a closet? granted... i have no idea what's on the other side of that wall.

Tough space. How about just a huge green plant or two? They will need to be artificial as you can't easily access them to water them (and the light is not so good).

I would rather not wall it off since those two recessed lights back there are on their own dimmer and provide nice lightning to the couch area for reading while watching TV. The plants are not a bad idea though. Any suggestions on what kind? I don't think I've ever shopped for artificial plants haha.

My guess is the room was originally designed to have the TV back there, but my sectional is too long for the other wall. Also, the wall would block the TV if you were sitting on the end of the couch.

How about a console table with a plant and a lamp on it?....console table could be a wide one....Then you could put some colorful large art on the back wall. Only have to worry about dusting the console table....If you can't find the right size, would be easy to make if you are handy.

Do nothing. Your pretty couch is tremendously oversized but if comfort is #1, the little gap is insignificant.

Lol okay. Actually seems like a great size. Thanks though.

I agree couch seems very oversized for the space. You might find a decorative standing screen you like.

I don’t understand. What size couch would you have suggested? It’s a home theater setup for family lounging, not a formal living room.

Don't clutter it up trying to fill the space & bring more attention to it.

1st try blocking it off with a decorative screen.

Can buy matching doors of your trim, connect with hinges, to make your own screen.

Put speaker behind.

Put a floor lamp behind to light up ceiling above screen for ambience.

Use that space for storage.

Later if it's working well for storage & you don't miss it in that room.

Consider extending wall & making it accessible from another room.

If you can move your furnishings about so you could access that corner, that would be a good place for a home office nook.

Alternately, you could close it off as a walk in closet, preferably accessible from the room on the OTHER side of the wall.

Are there, as it appears, at least three parts to your sectional? Have you tried putting the two end parts together and separating the rest of the sectional from it to place it elsewhere?

Would the entire sectional or at least the two end parts fit against the outside wall with the lounge end actually in the nook?

Save your muscles and sweat. Invest in a tablet of graph paper and draw, to scale, the size and shape of the room, indicating windows and doors. Then, using index card stock, draw the size and shape of EACH individual piece of the sectional and of any and all other furnishings in the room and cut out each shape. You can then move the shapes of the furnishings around in the shape of the room without throwing your back out of whack.

Something else to try on your graph paper: Move your tv either to the corner at the exterior wall and angle it toward the center of the room or. leaving it against the same wall, move it as far as practical the other direction and angle it toward the center of the room. Doing the latter, you may need to add a pony wall or the equivalent cabinet or bookcase behind it so you're not looking at the back of the tv and all the wires.

Like the idea of walling off the nook and making that space accessible from the room behind it best of all.

It seems silly to keep such a huge dead space just for 2 can lights. If you walled it off, wouldn't a lamp or two (with dimming capability) provide better task/reading light anyway? Otherwise you need furniture that allows physical access. Build a bridge? Raise the floor back there and make it an odd reading nook?

It wasn’t a mistake. The ONLY way to achieve an optimal front stage in that room, as well as not have the surround speaker in the middle of the floor, was to have the TV, front speakers, and sub on the flat wall. The choice was to to either put the TV in that nook and have a subpar front stage and bass balance, or put a couch in front of it. I’m a big audio guy so I chose to go for the setup that would give me the best sound in that room. It’s a shame to have to waste that space, but there was really no other way to arrange the room without sacrificing sound and visual quality (by the way, the TV is optimally placed 8 ft from the main viewing position).

Perhaps walling it off is not a bad option.

However, I again run into the issue of how to access the room if I did Wall it off because the room next to the nook is the furnace room and you would not be able to walk through it.

Would walling it improve sound?

Maybe a little. Usually walls or lack of walls are compensated for by the receiver though when you run the room equalizers. The big thing is you don’t want a sub in a nook like that and you want to try and keep all speakers the same distance from the main seating position, especially the front stage.

Since it's a, theatre, how about a thick movie curtain all the way across the back wall of couch pass knook. Storage "room" for stuff you rarely need due to limited reach.

As a fellow audiophile (albeit, the kind who can't actually afford to be a true audiophile), I approve of your priorities. I would think eliminating the nook would improve sound consistency, if not quality (consistent rebound from all angles--though the part of the room from which the photos are taken, I assume, is open?). Fun lighting solutions to go with amazing video and sound seems like a fun project, IMHO. Plus, you get extra storage.

You could make the nook a walk in closet with an "invisible" door (painted the same color as the wall) for the storage of items rarely used.

I love the screen idea! As mentioned, make it out of something tall (doors) so that the scale does not look off.