In part because I wanted to see what kind of speakers many are using with their TVs vs. room size, and how they are placed. While my living room is ~ 2660 cu ft, with a triangular ceiling that peaks at 11 ft, the short wall is only 11 ft and beyond one side of it empties into a long hallway and kitchen beyond that. So, diagonal placement of all A/V hardware is the only way. I don't expect much of a happy ending with any size TV.
There are lots of pictures of peoples rooms and speakers on this site. I'm not sure how to relate TV size and speaker size. In general TV size I think is related to viewing distance more than anything else, and what is practical. I think the type of program you watch also has a bearing on the issue as well and I will expand on that later. You also can not exclude aesthetics. You have in some way to make very large speakers fit into the room and be part of it. So to really max out the AV experience, in my view some room reconstruct is likely to be required. I also think people do impose complex multichannel systems on unsuitable spaces. I have to say I think this is common. We have to remember we got on very well with 2 channel audio being the reference standard for about half a century.
So of you want pictures here as some for what that is worth.
Here is the 7.2.4 AV room.
That room was new construction, but moved from our previous home were there was a room reconstruct. The Atmos was added in the new room.
This room is used mainly for concerts and opera, and CDs, BDs LPs and tapes. It is used for some movies and TV programs. The screen size is on the small size, but audio quality is prime in this room. It is wired for a PJ and screen, but I have never installed them. I worried it would adversely affect the center speaker. In addition with Atmos now so improved that instrumentalist are locked in position including depth and there is often a disconcerting disconnect between picture image and sound image. I have a feeling a larger screen would make this much worse.
This is my 3.1 room.
I would not remotely consider imposing more than 3.1 on that room. It is used mainly for TV watching both traditional and streamed. My wife uses this a lot. To be honest you can not easily tell the difference between 2.1 or 3.1. My wife insists there is no difference. I just wanted the challenge of designing a 3 way center channel. In two channel even when way off center the center image is still stable and centered in two channel listening.
Now the 2.1 system in the family room.
I really like this system. I really enjoy those speakers, and they actually have enough bass extension that the subs add little. The LF driver is one of my favorite drivers of all time. The KEF B139. Falcon acoustics have them in production and have increased power handling to 200 watts, although my drivers are KEF originals. Falcon have kept the T/S parameters identical. The mids are the NLA Dynaudio D76 domes.
The only comparable high powered mid domes are the ATC dome and the Volt domes. These cover the speech discrimination band at power. The Volt domes have recently become available in the US from Madisound.
I love this system and like to do some serious listening fireside in the winter.
So it comes down to making the best of what you have. But I don't think you should let your space control the quality of your speakers. Better speakers will sound better then poorer ones whatever the space. In fact my experience is that the better the speakers, the less they are impacted by shortcomings of the space, and there are good reasons for that.
