[crazygringo]

Well it's mastered for 5.1. True there aren't usually Atmos objects, but sometimes there are, but also there don't usually need to be. Are you taking issue with "5.1" being called spatial?

I couldn't disagree more about the "fake surround filter" though -- I love surround sound on my AirPods Pro, even when "spatialized" from stereo. It simply makes music and movies/TV so much clearer to listen to. Everything becomes more distinct and intelligible.

I understand how people rail against the "purity" of the original stereo mix's "intentions", but the reality is that when you listen to music on speakers, the amount of reflection and absorption in any room is already destroying that "purity". Spatial audio filters aren't "destroying" the audio anymore than speakers in a room already do -- the difference is that they're increasing clarity rather than muddying it all up.

I can't ever imagine going back to listening to flat stereo again, where the sound on headphones feels stuck inside of my skull instead of coming from outside.

Headphone fatigue is a real thing, coming from the fact that our brains aren't meant to process audio without all of the associated spatial cues. (Sound isn't supposed to feel like it's emanating from inside our skulls.) Modern surround filters do an awfully good job at restoring those cues. No more headphone fatigue.

[Cu3PO42]

Not the parent, but find myself agreeing with both of you, in a way. No matter if it's 5.1 or "proper Atmos", those mixes sound fine - or maybe even good, depending on your preferences - on headphones. I also have a fake surround upmix on an audio interface that I occasionally use.

But I almost always detest how these mixes sound on my actual 5.1.2 setup. The surround channels mostly consist of a bit of reverb that adds nothing to the experience in my opinion. In a car where there are physically separate channels, I'm not optimistic for the result.