Q: Why is Apple TV 4 movie audio quality so bad?

Good. So it's definitely a technical issue, not content-dependent. Not sure where to go from there. Have you tried all the ATV audio settings? Maybe reduce loud sounds, audio mode. If you set ATV output to stereo, is the level OK? Is the ATV audio output set to Apple TV?

As I said initially, I'm sorry if it comes across the wrong way, but you (as you seem to agree) don't seem to see what is obvious to me at least. What sort of explanation could you possibly have to support your position that it is nothing to do with your set up or equipment, given that others don't have this problem. How do you qualify your statement that it's the audio encoding in the movies themselves if others don't have a problem.

Sound is relative to your equipment.

The line output from the Apple TV for a given source is identical for everyone, any differences you hear can only be as a result of different settings or the equipment that the Apple TV is connected to.

If your telling me that if you play a blu-ray movie over your system, if you have a receiver and a 5.1 speaker setup, that it sounds the exact same as if you play the same movie via iTunes on the ATV4, than its very possible your not being honest.

All equipment I have connected to my Receiver produces different volumes, indeed OTT broadcasts to my TV over RF from different providers is different. Is the audio from my Apple TV very very poor and too quiet, no it's certainly not. Is it quieter than from other sources, yes but then it's also louder than from some other sources too.

Not everyone that experiences low volume with iTunes movie played via ATV4 is posting in this forum.

Not everyone who has an Apple TV use the forums admittedly, but when there is problem with the Apple TV that everyone experiences, boy do we know it, there is post after post after post about it. I've seen a handful of people post about the volume and in most cases it's due to the sound check setting or something similar.

I said, "There has to be something wrong with the way the movies are encoded, or with the way the Apple TV deals with the audio". One or the other.

Yes you did say that, but that isn't possible is it, we both have access to the same movies (which you agree that you don't get your own version of) and we presumably both have the same Apple TV since there has only been one version of the Apple TV 4.

I too have this problem.  It is only with the movies.  Netflix, and music have good quality.  Not only does the volume seem low, but it seems to have less bass and more treble overall.  All other devices (samsung TV and apps on it like Vudu, netflix, etc.) and Apple TV apps have good volume and quality.  Just apple TV movies for some reason.

I have this exact same issue. Audio quality isn't very good and need to turn it up much more than everything else (ie Netflix, Blu-Ray etc)

I actually think it has something to do with Apple's bandwidth and streaming settings.