55” or 65” TV Screen Size and Your Speakers: Please Join Survey

A little science (and history) from a guy who’s been designing and installing Home Theater before the term "Home Theater" existed. We just called it "Giant Screen" back on those days. (I still have a Kloss Novabeam stored up in my loft).

There is actually science to apply to screen size vs viewing distance. The theoretical goal was to determine at what size/distance a person with 20/20 vision could not longer resolve a pixel. For 1080P resolution, this number is approximately 3x screen height. The math is pretty straightforward for standard 16:9 aspect ratio screens. The height is 50% (+/-) the diagonal. A 65" screen image would be about 32 1/2" high, placing a minimum viewing distance of around. 8’. This would produce high resolution, artifact free image from that distance. This would also "assume" a native 1080P image, or content that is of sufficient quality to be upscaled with good results. Poor quality content may lack detail or resolution, but glaring pixels (that make the image look like your viewing through chicken wire) will not be an issue. Moving forward to 4k, that minimum viewing distance is cut in half. Yes, you can sit less than 5’ away from the screen and have a nearly perfect image with quality content with a 65" screen.

Another often overlooked aspect of viewing and vision is that our peripheral (side to side) viewing is greater than our vertical (top to bottom) vision. The sense of overwhelm from large image is due to image height, and not so much image width. The older days of 4:3 aspect ratio screens, a 70" rear projection TV could be quite overwhelming, both physically and from a viewing perspective. That 70" image was 42" high, roughly equivalent to a 85" 16:9 screen today.

Here’s one more reason to go BIG:

If you watch blockbuster movies, these are (almost) always "letterbox" or 21:9 aspect ratio. This reduces the image height fairly significantly, around 60% of the full 16:9 height. So, doing the math: a 65" screen will produce an image size of approximately 57" wide by 24" high. In this case you are, literally, watching the equivalent of a 48" television. Which brings us back to the good "ole" days. Imagine that massive 35" CRT television that you just bought for the family’s enjoyment. After setting up and testing that set on full-screen broadcast, you quickly reach in your Laserdisc library for a "correct" (not panned an scanned) version of your favorite movie, and .... huh??!! That beautiful new 35" set is displaying a 12" (YES, TWELVE INCH!!) high image. A bit underwhelming, to say the least.

A word on center channel:

Yes, center channel is the way to go. One consideration is room acoustics (or lack of them). When using 2 speakers to produce an "phantom" center channel, you have energy emitting from 2 speakers (often close to room boundaries) to produce that center channel information. With a center channel, you’ve cut the complexity of the signal (and its resultant reflections) in half. We’ve had highly reflective rooms where dialogue was unintelligible with 2 speakers, and "tolerable" when the burden of center channel info was sent to a single dedicated speaker.

You should have plenty of data b y now. I've seen this thread on at least three different sites.

BTW, my opinion is that you will have to compromise movies or music when you combine the two. You will have to be ok with that, and pick which one you want to prioritize at the detriment (however slight) of the other one.

Another option if you are not pressed for cash is both a TV and a projector. You can mount the 55” TV as planned. Then put a pull down acoustically transparent screen in front of your speakers. Best of both worlds. Bit movies at night and no 2ch compromise. 
 

some of these cheap life style projectors are good enough for the casual movie watcher. 
 

https://www.valerion.com/visionMaster

TV- definitely the 65. I have either the Dynaudio Heritage Special or Devore Super Nines 

@waytoomuchstuff thanks for all the science, very interesting and informative.  OP, here's another strong vote for the 65. My listening room is ~ 19' x 14' with a 65" TV centered on the end of the rectangle. It's flanked by a pair of Magnepan 3.7s and a Perlisten D15s sub a few feet forward of the TV wall, and I have Ikea Poang chairs ~ 15' feet from the TV wall. My 65" TV is great but getting older and when I replace it, I will likely opt for a 75". I have definitely never wanted a 55" in that space. When the 65" TV is off, it does look pretty damn big hanging on the wall. But when I turn it on, it seems like the right size if not slightly too small. I don't use it very often but I will occasionally watch sports with the sound muted while spinning records. I don't think you'll regret getting the 65". I suspect you will regret a 55". Every now and then, size does matter. 😉