Mine's on my laptop with headphones. I don't even have a TV, let alone a fancy sound system setup (and have no clue what those numbers everyone's throwing around even refer to).

X.Y (e.g. 5.1) means X wide range speakers and Y subwoofers. You also sometimes see it like S/T.Y where S+T = X, and it refers to front/surround speakers.

There are standard values and configurations, such as 2.0 (aka stereo) both at the front, 2.1, 3.1 adds a centre channel mostly for on-screen dialogue positioned close to screen, 5.1 (3/2.1) adds a second stereo pair behind you, 7.1 - adds an extra surround stereo pair between the others, etc.

For real enthusiasts, also X.Y.Z, adding ceiling/bounce speakers for vertical spatial audio.

The real "stuck so far behind" that I don't get is why we use speaker arrays at all -- instead of binaural stereo tech. That virtual haircut demo, apparently from the 90s,[0] sounds incredible on my cheap headphones, yet the technology seems to have gone nowhere since. Is there even spatial audio in VR setups?

If the difficulty is in simulating the head/ears, then existing spatial recordings can at least be converted using a binaural microphone in a surround sound setup, no? Though, I guess with headphones any visceral sensation of bass is still lost, so you'd need to keep the subwoofer or a seat shaker.

0 https://www.youtube.com/watch?v=IUDTlvagjJA

I don't much about audio, but wouldn't binaural stereo only work if the two speakers are to the sides of you, like with headphones? Would this work from a TV that's an ambiguous distance in front of you?

As a side note, Windows (and Xbox) support Windows Sonic, Dolby Atmos for Headphones, and DTS:X, all of which simulate spatial audio for headphones. It'll simulate a 5.1 (and 7.1?) setup through the headphones. Some games have spatial audio simulation built-in as well, such as Elite Dangerous. I believe UE5 also has a spatial audio engine. Finally, I believe PlayStation emphasized spatial audio for the PS5, but I don't really know the details of that.

I think it only works/is a lot easier with head/earphones? Since you know exactly where the ears are w.r.t. the speakers in that case.

Not that that's really an explanation - if that was the best sound and it was available on Blu-rays and streaming platforms, and legacy 5.1 content upmixed nicely, then yeah why wouldn't I use headphones even at home in front of the television. Less obvious for joint/family viewing I suppose.

Binaural audio starts to really fall apart when you don't have the sound exactly as the microphone setup was. Moving the speakers even a couple of feet away, and then not having them exactly lines up with your ears, it ruins the effect.

Wondered this too. That video along with the millions of ASMR videos on YouTube have very nice binaural stereo sound, but I don't see this being done anywhere else.

And that's perfectly fine, don't get me wrong. If that gets you enjoyment from the media you watch, that's great. You definitely don't need a fancy theater room to be happy.

And honestly if it's a nice laptop and a good pair of headphones you're probably ahead of a lot of people watching on a cheap TV with built in speakers. Once again, not that it truly matters.

I upgraded my receiver and TV recently and it was a pleasant surprise that Apple TV remote now switches the receiver on and off automatically so the setup really requires no tech awareness to use.