Apple Broke Dolby Digital 5.1 Output on Apple TV 4K

I have Apple TV 4K 1st Gen and use it in combination an older Sony Receiver STR-DB790 and an HDMI audio splitter as the STR-DB790 does not have HDMI. In this way I can use 5.1 surround and also DTS (no Atmos though as my receiver simply is too old). I had no problems at all whilst on TvOS 17.x After updating to TvOS 18.0 I immediately lost all surround (incl. DTS) to the Apple TV box.

All audio was reverted back to 2.0. Strangely enough only the Youtube App on the Apple TV box still gave me 5.1 and 5.1 DTS.

Alle other apps on the Box only gave 2.0. TvOS 18.0.1 did not solve it.

Yesterday I updated to 18.1 (public) and now I have 5.1 and DTS back. I am so happy. So this updated fixed it for me but I read in this thread that others who already had the issue before TvOS 18.0 still seem to have it.

The latest TVOS 18.1 fixed mine. My AV receiver is ancient Yamaha DSP-Z7 that supports hdmi 1.3 and DD/DTS (no DD+ or Atmos). It seems like the new update fixes DD 5.1 but still has a problem with DD+ or ATMOS (specifically when the source is DD+ Atmos and the sound output is set to AUTO, not forced to DD 5.1)

I have exactly same problem now, not sure what happened as I have automatic updates of tvOS, it started with Netflix, the 5.1 sound has stopped being passed through the Yamaha Receiver. Now it show me only PCM. Although I was still able to pass DD while using Fusion media player playing back some movies in 5.1. But then in order to fix Netflix I did reset of Apple TV. It seem to be updated something in background and now I don't have DD even on the Fusion Player, and Netflix too... I see my tvOS is version 18.1. I have first gen Apple TV4K

Called Apple support, they said they are aware of the problem and working on it, they opened a case with me so hoping the fix comes with next release 18.2 which seems to be expected in December. Btw I didn’t see anything in release notes for 18.1 addressing this particular issue, not sure how it worked for some people? Or maybe I missed something?

Many commentators get their posts deleted when they propose solutions,

my gen 1 atv 4k 5.1 issue resolved once I installed 18.1. I can mention 18.1 now as its now released.

not tried if for a week but hope it’s still fixed.

what generation of atv are you using and are you running the latest release of tvOS?

18.1 didn’t work for me, I have 1-st gen 4K. Did complete reset with update but still no 5.1 audio. My AppleTV is plugged to Samsung TV with HDMI, then the audio goes from the TV to AV Receiver with optical cable. Before v18 all worked well since 2019. Now it’s not…

Thank you very much for posting this information. I own both models A1625(HD),

and A2169(4k). I swapped these units out and the A1625 model outputs 5.1 audio to my Sony non hdmi receiver in 5.1 perfectly using the optical audio cable from my tv to the receiver. Both models are running 18.1 iOS, so it seems to me that is not the software version causing the issue but a bug in the Apple TV 4K units. Problem solved for me at the current time. Thanks!

OK, unfortunately this did not help me, even though I have the same Apple TV and also version 18.1. I use an optical cable from the Apple TV to my ONKYO receiver. I will try to connect the HDMI from the Apple TV to my receiver instead of to my Samsung TV. Maybe this helps. But I do not think so. Strange that it works for some.

Klasson wrote:

… optical cable

The use of optical cable for audio, requires that the Apple TV audio output format is set to Dolby Digital 5.1 (or Stereo). The “Auto” PCM Multichannel configuration is not compatible with optical. That would need HDMI, which has much more bandwidth.

It was compatible before os18, not sure what they did but I used optical cable from TV to AV Receiver and it was working for years and I had DD5.1

Switching from Auto to DD5.1 in ATV still doesn’t make any difference at least for me…I get PCM on Receiver.

Apple TV 4K Gen 1 > HDMI > LG OLED B3 > Optical > Sony HT-RT3

I am on 18.1 and only get 5.1 if I set Change Format to 5.1 whereas it used to work fine having it not change formats. I’d prefer it to just be pass through as it was rather than Apple re encode the audio. Please fix this!

As optical doesn’t have the bandwidth for “Auto” PCM Multichannel, you would need an HDMI (ARC) connection for that. While using optical, you would need the force the Dolby Digital 5.1 or Stereo format. This hasn’t changed with a recent update.

I have the ATV plugged to the Samsung TV with HDMI, then from TV I have the optical cable going to the AV Receiver , with this setup I had DD5.1 on the AV Receiver for last 5 years or so and had 0 issues. So few weeks back, not sure exactly when the tvOS 18 was updated but I lost DD5.1 on Netflix initially. Meanwhile when I was playing some movies from NAS on Fusion player I was still getting DD5.1. But when I did complete reset and Update of tvOS everything stopped working, even the Fusion player isn’t pushing 5.1 anymore. I tried all combinations of audio settings both on ATV and on Samsung TV which btw doesn’t have pass through option. But I didn’t needed that before. So I don’t know what’s happening. Waiting for next tvOS release and hoping something will get fixed as Apple Support told me they are aware of the issue.

I updated to the 18.1 b*** , a while back, and that fixed the issue for me. Since then I've turned off auto updates..

Now I wonder if it's safe to go to the public 18.1, or will that re-instate the issue? (Having issues with Infuse and want to see if changing the OS will fix it.)

I have the Apple TV 4 HD.

I tried all combinations of audio settings both on ATV and on Samsung TV which btw doesn’t have pass through option.

My 2021 Samsung TV allows this setting option for optical connections to an audio system:

Home (on remote)﹥Settings﹥Sound﹥Expert Settings﹥Digital Output Audio Format: Auto (DD 5.1 if available in the source) or PCM (downmix to 2.0).

In Samsung’s settings and naming convention, Passthrough is only available for HDMI connections (eARC).