Apple Broke Dolby Digital 5.1 Output on Apple TV 4K

Maybe turn off auto update and stay on 17.x with that one until 18.x issues are resolved.

18.1 did not solve the problem for me

Apple TV 4K gen 1

LG G1

Sonos Beam 2

I know that it was working before 18.0 for two reasons. First, I've been bitten by similar issues before, and I have a button on my Marantz AVR's remote that shows me the input schema and the output schema. I used that almost daily. Second, I change the setting almost daily for my Apple TV HD. I'm switching sound output devices, and have to know which setting gives me surround sound.

I have left my update settings on auto, but for reasons I don't understand, I always have to apply updates manually on both my HD and 4K units of Apple TV. That part of it is a huge question mark for me.

I'm posting a subsequent reply, but due to some gray area concerning posting guidelines, I'm not sure whether it's permitted. If you see it, great, if not, then this will have to suffice.

I was also interested in trying a version of tvOS that comes after alpha, and it appeared to work momentarily. When I turned off after alpha updates, then enabled subtitles, the issue returned. That is very much vexing for me, and I found it difficult not to become flamingly livid.

Here's what I've observed on my two ATVs (3rd generation HD, and 1st generation 4K) since installing tvOS 18.0. I have about three Dolby Digital 5.1 compatible sound systems that I use interchangeably. If I disable Change Format, one of the sound systems (Marantz AVR) receives multichannel audio. The other two don't. If I enable Change Format and choose "New Format: Dolby Digital 5.1", none of them receive multichannel audio from either ATV. I'll admit, I'm old, and I couldn't care less whether the audio is described as PCM or Dolby Digital or Atmos. But (on a good day) I can still tell where sound is coming from (at full frequency range, at least).

I’ve got the same issue on two AppleTV 4K devices. When I connect the hdmi into my Rotel preamp and start a movie, my preamp reports multichannel PCM. It no longer shows Dolby Digital + or DTS. This is very irritating because you can’t roll it back.

Well thats it then for me.Two AppleTV4k go in the garbage. I’ll go elsewhere. My bet is they changed something in their the architecture and it’s up to all of the app vendors to alter their code. I wonder if we could get more traction by opening defects with each vendor? Too much work when there are cheap alternatives.

My lg TV is an older one, so I'm using regular ARC but it did used to pass through multi channel LPCM and Dolby 5.1 without any issues.. my inbuilt Apple TV app on my TV passes Atmos (probably compressed) and DD 5.1 to my soundbar without any issues.. my fire TV sticks apple TV app does the same without any problems.. this issue is just with my apple TV box.. what is strange is YouTube on my apple box seems to play DD 5.1 just fine

Just to be sure - my soundbar informs me that the sound being played is not in Dolby (red light instead of green). But does that mean that the sound is not necessary stereo? So a movie recorded in Dolby will be played as multichannel and I will hear the sound in the speaker in which I should hear it? It doesn't sound bad, but I'm worried that I just had Dolby sound (green light) before the update. This is all very weird to me.

My Apple TV 4K is running tvOS 18, connected to my AVR.

When using the Apple TV 4K, with the AVR in "Straight" mode and watching some simple show that doesn't use multi-channels like say the news or some show that is just in stereo, my AVR display will indicate stereo two front channels only. If I watch a movie in whatever app I am using on Apple TV 4K, Amazon Prime, Hulu, etc. My AVR display will indicate multi-channel mode in my case 5.1, this is all while in "Straight" mode.

Can anyone let me know if this is happening also in atv 4k 2 or 3 generation? Because it seems that the only one affected is atv 4k 1st generation. If anyone can please confirm I really appreciate. Thank you

Sept 20th, 2024,

I spoke to a Apple Senior Tech who advised me they were not aware of this situation. I gave as much detailed info as possible based on the conversations left on here. The AST said he would touch base with me in 24hrs with any follow up. Please standby.

Sadly that is all I can say for now.

I would do the same but I have a whole lot of other issues using the apple TV app on fire stick and also my LG TV, the issue is some movies ( usually universal movies) only play in HD HDR for some reason.. when you're watching a movie and press down in the remote it gives you the info of the movie, it says HD HDR and not UHD HDR.. I'm in the UK so maybe it's just an issue here and probably a conversation for a different post