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Payton Garner Author

Level 2

341 points

Apple Broke Dolby Digital 5.1 Output on Apple TV 4K

Not sure why nobody else is mentioning this, but figured I'd post to help others. One of these last few tvOS updates has completely broken Dolby Digital output (on Apple TV 4K, it seems).

I have a 2nd gen 4K model that had been fine until a recent update. I change the audio output in Settings to force Dolby Digital 5.1 for my speakers (Logitech Z906), but this suddenly no longer works! My speakers do not light the proper "Decode" light to indicate a true 5.1 signal, and the voices clearly come from left and right channels instead of just the center.

This was easy to confirm. I purchased a brand new 3rd gen Apple TV 4K (128GB) and it shipped with tvOS 17.1. I configured the audio output to force DD 5.1 and tested a movie... and everything worked perfectly. The "Decode" light indicated a 5.1 signal and voices, etc, clearly only came through the center channel. Then I upgraded to tvOS 17.4 and immediately tested the same movie, and it's broken! Nothing else changed.

Strangely enough, I have an old 1080p Apple TV running tvOS 17.4 (latest) and it still outputs Dolby Digital just fine.

I have provided this information to AppleCare as well as Apple.com/feedback. Kind of a ridiculous bug to go unpatched still. Hopefully someone will notice while we all sit here with broken audio.

Posted on May 7, 2024 10:30 AM

Top-ranking reply

Mcshoes

Level 1

38 points

Posted on Sep 16, 2024 10:59 PM

updated to TvOS 18 and 5.1 is broken. Apple TV connected to TV Samsung KS8000. HDMI ARC to Yamaha receiver. Only detects stereo. Please fix asap.

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255 replies

Oct 3, 2024 9:34 PM in response to Payton Garner

I have an Apple TV HD and can’t find the solution that people are saying is working for them.

Apple TV > Samsung Smart TV > optical > Sonos.

PlayStation, Sky Stream, smart tv apps all output Dolby digital. YouTube surround test works, otherwise the Apple TV reverts to PCM stereo.

This was working fine, but now can’t get it to work. I’ve tried everything I can.

Oct 7, 2024 1:42 PM in response to BUSHleagueBRO

Atmos was never a problem for me. It was non atmos 5.1 stuff that was being down mixed to pcm stereo instead of DD5.1 when I selected DD5.1 in the change format option. Are you saying that’s fixed? I’m not near my box to check but 🤞🏻it has been sorted out.

Oct 7, 2024 4:30 PM in response to Payton Garner

I just updated and 5.1 is back! You have to update to the newest B version. If you aren't seeing that option, try re-logging into your Apple account. I had to do that on one of my ATVs. So happy 5.1 is back.

Oct 9, 2024 2:30 AM in response to Payton Garner

I was quite fortunate to have 2 x individual 4K Apple TV pucks. One of them updated to TVOS 18 resulting in a loss of DD5.1 via my Yamaha AVR. The other remained on TVOS 17.6.1 and still supported DD5.1, so I was able to switch the pucks over.

note to self: Disable auto updates. Only update one and review for bugs.

The b version has fixed it the issue for me, but still keeping the other on 17.6.1 until the official update is pushed out for me to review.

Thank you to those of you that started of the thread, and reported to A HQ.

Payton Garner Author

Level 2

341 points

Sep 17, 2024 7:26 AM in response to Paul Brook

Unfortunately, I’m beginning to think this “bug” is more of an architectural change to how Apple TV 4K handles Dolby signals overall, and our specific configurations and equipment just happen to be victims of this codec adjustment. As it has been an issue so long now, I don’t have lots of hope this will be addressed. The best thing we can do is give feedback here…

Feedback - Apple TV - Apple

Since audio is half the experience, this is difficult to accept. After all, if all of our Apple TVs started outputting 1080p instead of 4K, I’d imagine that would be fixed by now.

Until we get eyes on this from engineers, just continue to send feedback and hope it gets noticed. At least this thread lets people know they’re not alone.

Payton Garner Author

Level 2

341 points

Oct 4, 2024 11:49 AM in response to llee

Interesting. Sounds plausible to me. Here's that documentation on Apple's Dev website for the technical crowd:

AudioConverterFillComplexBuffer(_:_:_:_:_:_:) | Apple Developer Documentation

Also might explain why this works for some apps and not others. If that particular app is using another method or API to convert audio, it may not be affected.

Aug 26, 2024 7:23 AM in response to Clwinbe

The Apple TV box wouldn’t output (nor passthrough) in Dolby Digital Plus or DTS. PCM Multichannel is as expected.

Aug 31, 2024 6:46 PM in response to dogdayediting

Glad Apple has known about this issue since older os’s and have not mentioned or addressed it. Had to get another streaming device so I could have proper sound

Clwinbe

Level 1

29 points

Sep 10, 2024 12:46 PM in response to Payton Garner

There are other solutions out there. I’m ready to ditch two Apple TV 4K and be done with this foolishness. It’s to aggravating and too easy to switch for cheap.

Sep 17, 2024 8:15 AM in response to ricardoalejandrodawson

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

Sep 17, 2024 9:08 AM in response to Payton Garner

It doesn't matter which you use in the settings.. it only plays stereo pcm

Sep 18, 2024 6:07 AM in response to mancsteveuk

Same for me. But the TVs onboard Apple TV app plays 5.1 DD without a hitch.

Sep 18, 2024 6:27 AM in response to nhojmselkcip

True, the same for me. The ATV app inside the LG TV plays the right format. (but does not support iTunes extra)

Sep 19, 2024 5:16 AM in response to Urquhart1244

I no longer get sound out of my surround speakers so it's an issue with the apple TV software..also setting my apple TV to Dolby 5.1 used to show up on my soundbar as Dolby audio now it doesn't.

Sep 19, 2024 5:40 AM in response to Payton Garner

I'm having the same issue which broke Dolby 5.1 after updated to tvOS 18. Please support. Tq.

Apple Broke Dolby Digital 5.1 Output on Apple TV 4K