Apple Broke Dolby Digital 5.1 Output on Apple TV 4K

I'm in the UK, same problem here.. I've also noticed YouTube does play in Dolby Digital but apple TV app and Amazon video only play in stereo

I can confirm. I turned on my AppleTV 4K today, and noticed I had to accept the "Terms and Conditions" which usually means I received an update. I checked my AppleTV 4K version and it is TvOS 18. Any content other than Dolby Atmos movies will not decode correctly. It will show up as PCM (2.0). For example, I am watching "The Man In The Iron Mask" on my AppleTV 4K which is natively English Dolby 5.1, AAC (according to Apple's website) but decodes as PCM 2.0. I know some of you will argue that "it means loss-less" which I will tell you now, it is nonsense, because there is a sound quality difference between my AppleTV 4K vs using the Apple TV Application on my LG TV. On My LG TV using the AppleTV application, it decodes correctly as Dolby Digital+ and has a much fuller sound. I am willing to guess, the update broke the AppleTV 4K device and aside from movies with Dolby Atmos, it is playing in Stereo 2.0 and when my AVR upconverts it, it sounds terrible. Please FIX the problem if you want me to continue to use your device. I could easily just use the native AppleTV application on my LG, but because I want to like Apple products, I am going to ask that you fix the problem! PLEASE SEE IMAGE BELOW of APPLETV4K vs THE LG APPLETV Application.

The Apple TV box has always done PCM Multichannel out, for the “Auto”/best quality audio format setting. PCM does not mean 2.0 per se; it can be up to 7.1 for Apple TV, if the HDMI connection allows for that. The Apple TV box will not output Dolby Digital Plus, nor did it do so recently, even when that was the input. There is no passthrough option (since tvOS 10, I think).

1. While the conversion to PCM Multichannel will be lossless, your audio equipment can decide to treat these two formats differently, in post-processing. That may depend on your audio system and/​or its settings.
2. There could be HDMI bandwidth restrictions that force a lesser format, but if you are getting Dolby Atmos, then this wouldn’t apply.

I am willing to guess, the update broke the AppleTV 4K device

It didn’t. It just says 7.1 on my 7.1 AV receiver for Apple TV 4K on tvOS 18, for 7.1 sources.

Please FIX the problem… I am going to ask that you fix the problem!

Apple will not see your concern here in the forums. To notify Apple on structural issues, please use the feedback form. Feedback - Apple TV - Apple

Just manually updated to TVOS 18.1 (22J5543e) and the problem is still there.. I bought this trash because I thought apple were one of the best tech companies in the world hahahaha

It works on my Apple Tv 4K. You have to play a film and then, while playing, you have to change the audio output as Edwy7580 mentioned. It doesn‘ t work in pause mode.

Until 18.1 is released, it isn't really fixed.

Same with tvOS 18.1 and Apple TV 2. gen.:

No Dolby 5.1 when not changing Audio Format - Atmos is OK - all other is PCM on LG OLED-TV and LG Soundbar.

@Apple - find a solution asap, please

I am having the same issue with my setup as well. After a recent update I can’t get Dolby atmos through my Sonos system. No apps play Dolby now, I only get stereo. The only thing I can get to play Dolby is apple music.Everything worked until the last update.

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

Another update: I've just had another experiment. I played "Octopussy", a film with a DD5.1 soundtrack. Played directly from the Apple TV is plays in PCM 2 channel stereo. Selecting the same film in the TV app on my iPhone and using Air Play to cast it the Apple TV, it plays in DD 5.1.

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

I have a 1sr generation Apple 4K TV

Before the latest update iOS 18, I was able to get digital sound through my Yamaha speakers through optical out now the Apple TV unit is only giving me pro logic,

I’m able to get digital sound when I’m using Disney+ or Apple TV app via my LG TV

So I clearly know it’s not my sound system or the TV it is actually Apple TV unit itself.

not sure when Apple will find a patch for this probably in 18.1 I’m hoping

When connected through a high speed HDMI cable to my Marantz AVR, if I disable Change Format by entering Audio Format of the Audio section of Video and Audio in Settings, the Auto connection is activated as default and available multichannel audio is correctly received by the AVR.

That's Settings>Video and Audio>Audio Format (from the "AUDIO" area)>click the Change Format option. The option then shows Off, and the New Format line vanishes. That's the way it is on my 1st Generation 4K and my 3rd Generation HD, at least.

However, there appear to be enough incompatible audio systems that it may not be possible to know if it will work with yours. I do believe that the Change Format option would not have been provided unless lots of audio systems capable of playing multichannel audio needed it.

Does the 3rd gen ATV produce 5.1 with the Sony TV and Beam? That would be an interesting test

My findings:

Sony Bravia XBR-49X900F

Sonos Beam Gen 1

ATV audio set to Change Format to 5.1

ATV 4k 2nd gen (A2169) tvOS 18.0 — 5.1 broken. Tested audio connection from TV to Sonos via both optical and HDMI arc. Worked fine with tvOS 17 (up to and including 17.6.1)

ATV 4k 3rd gen (A2843) tvOS 17.4 — 5.1 fine. Audio connected from TV to Sonos via HDMI arc