LPCM surround/LFE missing in tvOS 17.2 beta

Since yesterday, I figured that there is no surround and LFE playing through subwoofer like 1 channel and the other is altered.
After troubleshooting I found that there is no surround audio coming from speakers except the left and right channels.

Now the only way to get surround audio back is to set audio output to dolby digital in the change format in the Apple TV settings.

Attached all the settings I was using before.





Which model Apple TV do you have?

Is this affecting all videos or just some?

It seems there may be a bug in tvOS 17-17.1 where audio on the 2022 ATV4K is being sent as 44.1kHz instead of 48kHz, so it’s possible Apple may be making some changes in this area which are a bit buggy right now.

I have Apple TV 4K 2021 model

Thanks. We’ll keep an eye on this as the 17.2 beta process moves on.

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I have re checked now, and found that in both situations when changing the Audio format to dolby digital or set it off and sample rate is 48KHz.
Also, when selecting dolby digital the surround work fine in infuse, but when playing music through Spotify the sound comes only from Left & center channels (playing stereo and receiver set to Straight).

I was able to replicate this issue on a 2022 ATV4K.

Observations

  • LCR audio is correct
  • L/R surround audio comes from the L/R front speakers
  • LFE is missing

Setting the Apple TV to output Dolby Digital 5.1 allows all channels to work correctly.

The same issue can also be observed when playing 5.1 content over AirPlay, so I think it’s safe to say this is a system bug that Apple needs to fix.

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I’ve got this issue as well, exactly as you’ve described. It’s not been fixed yet and I have the latest Apple OS beta, so I’m a little worried it won’t get fixed any time soon. I’ll report it as others no doubt have, fingers crossed they deal with it soon.

Mod Edit for clarity.

I finally got a chance to sit down and test some films and demos doing an A B comparison between my AppleTV 4k 3rd gen with Infuse vs Nvidia Shield Pro 2019 with Plex on my home theater and something is seriously off. I immediately noticed a pretty large absence of bass from my subwoofer with the ATV and Infuse combo with the same volume on my receiver. Plex was the same. I’m not sure if this has anything to do with the latest 44 kHz issue of tvOS 17.1 impacting the LFE channel. This is not a volume issue or volume normalization as raising the volume barely impacts the bass. DTS-HD tracks seem a lot worse than True HD.

Receiver info shows the LFE channel so not sure why there is close to zero bass on this DTS-HD Master track. I dont want to post any copyrighted content as a sample. But would be happy to send to an admin. What else can I look at?

Setup: AppleTV 4k > Denon X4400H > LG OLED C8
tvOS: 17.2 (21K5341f) Beta
Infuse: Infuse Pro 7.7 (4620) Beta

This is a bug currently present in the tvOS 17.2 betas. Moved your post to this thread which has more info.

Installed the latest Beta last night sadly still not fixed

Latest beta still happening. I attempted to opt out of beta reset and update back to a stable release but tvOS says cannot download the latest update right now. Try again later.

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Sadly, this is not possible with tvOS. You have to wait for the next regular update to really quit the beta. Confirm by Apple Support… So, your best way is to stay on the beta program and wait for the release candidate and quit the program at this time. Earn this between 17.0 and 17.1…

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FYI, new 17.2 beta dropped

Surround is back, but LFE is not back with the same quality.

Hmm not seeing it yet, is it a Developer Beta? I have Public Beta selected

Yes, its a developer beta not public beta.
Public beta will be released tomorrow I think

Got it, LFE track is back for me and surround is correctly played in the rear. 48 kHz is also back on my Denon audio stream info. Seems like it fixed two issues.

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Not hearing any difference between a Nvidia Shield Pro playing the same file. LFE channel sounds the same to me. What are you experiencing?

Confirmed!

In a few quick tests, this appears to have been resolved for multichannel PCM audio in tvOS 17.2 b3. Surround channels and LFE are now working as expected. :raised_hands:

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Not for me.