Apple Broke Dolby Digital 5.1 Output on Apple TV 4K

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

I want to add to this. I was going nuts because I have paid extra for Dolby Atmos on Netflix, Prime, Max, Paramount and Disney.

Netflix, Disney and Prime have lost Atmos on the Apple TV......It is now labled "Spacial Audio" so those three services are not handshaking with the Apple TV version 18.1. My Sonos APP says the Spacial Audio is 5.1. On the bright side, Max and Paramount Plus are still reporting Dolby Atmos and my APP says that's what I'm getting. The Apple TV on screen display reports the DOLBY ATMOS in the upper right as well.

I own a Fire TV that is Atmos compatible and I tried it on the same TV setup as the Apple TV and amazingly Netflix reported Atmos on the Fire TV and also on my Sonos APP. The same movie on the Apple TV reported as Spacial Audio.

There is something seriously amiss with the Apple TV and the three streaming services I mentioned.

Anyway, let me explain the situation as I see it. If your audio system is automatically detected by your Apple TV as a system that can use multichannel audio, then fine, you're one of the lucky ones. However, Apple engineers created a back door for audio systems that can use multichannel audio, but which are not recognized as such by the Apple TV. For the people who need it, it's the only way to receive multichannel audio. A simplified summary of the back door is the "Change Format" option. I'm convinced that it's this back door, the "Change Format" option, that is broken.

As others have stated, I can get 5.1 from YouTube and that's the only app. All others had 5.1 broken at the 18 update. I have a 1st gen 4K. The workaround doesn't work for me. I've been trying to mess around and find a different workaround but nothing has helped. I see on my receiver that the Apple TV is switching the audio signal when I start a program that should have 5.1, but then just goes back to stereo. This switch is normally where it would switch and stay on 5.1.

[Edited by Moderator]

Agreed. I have two Apple TVs and this update broke them both. They work perfectly fine except the crippling the update has done and no reason they should be replaced. I'm not purchasing another one because of that. I'll switch to something with more freedom. Updates breaking important features is not something I will look passed. I really hope Apple makes good and fixes this soon but so far, it seems they won't even acknowledge it.

Same thing happened to me after the tvOS 18 update on my Apple TV HD. I change the audio output in Settings to force Dolby Digital 5.1 for my speakers (Logitech Z906). I pass my audio from the tv to the speakers with a TOSLINK optical cable.

A fix that worked for me. I temporarily switched my audio output to my HomePod mini from the Control Center and then switched back to TV speakers. Now I am getting a 5.1 signal. It works with AirPods too. As long as you switch the audio output to something else and then back to TV, it seems to correct itself.

Definitely a bug that Apple needs to fix.

I thought I saw someone with a 4K say it worked for them but maybe I'm misremembering. I know it hasn't worked for me switching to earbuds or bluetooth speaker but I don't have a HomePod. EDIT: It was someone on another forum with a 4K 1st gen who got the workaround to work.