Apple TV 4K - tvOS 18 breaks DD5.1 for some users.

[Barrovian]

I've just updated my ATV 4k 1st Gen to 18.0 and I've lost 5.1 DD. Connection HDMI (eARC) to LG c1 to LG soundbar. Atmos is fine but everything else seems to be in 2.0 I've tried different settings combinations on the ATV and the TV but nothing changes. DD 5.1 was working perfectly before tvOS 18. All other connected devices, Sky Stream box, 4k player, Humax Aura PVR are fine. Annoyingly, the TV's onboard Apple TV app plays DD5.1 content perfectly
There are a few threads on the Apple Communities about the issue. Just wondering if anyone here is seeing the same thing.

 

[waw74]

any particular app?
I can try when I get home

have an LG CX and sonos Arc.

 

[Barrovian]

any particular app?
I can try when I get home

have an LG CX and sonos Arc.

So far it's anything at all on the Apple TV. Purchased films, tv series, Netflix, Disney+. Prime Video. If it's Atmos that seems to work, but anything that's 5.1 is down mixing to PCM 2.0. No amount of changing settings on either the ATV or the TV make any difference.

 

[Barrovian]

Just a quick update. Using the You Tube app on the ATV, I found a Dolby Digital Demo. That plays in perfect 5.1. The soundbar reports DD coming from the ATV via the TV to soundbar. Switch to a DD5.1 labelled film and its back to PCM 2.0. But if I use the tv's onboard ATV app, the same film still plays in DD5.1. So frustrating. Ive not changed any settings on either the TV, the ATV or the soundbar, save for the tvOS18 update. To a layman like me, tvOS18 seems like the obvious culprit.

 

[xuncia]

Same here, app ATV from tv plays the correct sound, but the ate box plays PCM stereo even if the movie is DD 5.1, and this is after the TVOS update I think from 17.1 up to 18.
The configuration was the same and before was working perfectly and the difference was clear in the surround, now everything is played on stereo. my configuration is ATV->LG EVO 55 -> SONOS system.

 

[Bobt_smf]

I've just updated my ATV 4k 1st Gen to 18.0 and I've lost 5.1 DD. Connection HDMI (eARC) to LG c1 to LG soundbar. Atmos is fine but everything else seems to be in 2.0 I've tried different settings combinations on the ATV and the TV but nothing changes. DD 5.1 was working perfectly before tvOS 18. All other connected devices, Sky Stream box, 4k player, Humax Aura PVR are fine. Annoyingly, the TV's onboard Apple TV app plays DD5.1 content perfectly
There are a few threads on the Apple Communities about the issue. Just wondering if anyone here is seeing the same thing.

Yes same here but just to make something clear, this issue is only happening with the 4K 1st gen ApTV. I have 2 1st gen and One 3rd gen here. Third Gen is fine. Seems iOS 18 broke this on the first gen devices. Not a happy camper here. This needs to be fixed. I noticed it on our Family room TV, using an old but servicable Preamp power amp system. It will not switch in 3/2.1 mode anymore, but only with the Apple TV device, Cable box and internal APPS on the Sony tv work fine and the receiver displays the correct codex is being received. This may be hidden from some people as many modern Recivers and soundbars will take a stereo signal and matrix it into a sort of 5 channel sound field, BUT it is NOT the same as a true Dolby 5.1 signal or sound for that matter. Seems this happened back when 17.1 came out a year ago but was fixed with subsequent updates so I think I could be fixed.

 

[Barrovian]

Same here, app ATV from tv plays the correct sound, but the ate box plays PCM stereo even if the movie is DD 5.1, and this is after the TVOS update I think from 17.1 up to 18.
The configuration was the same and before was working perfectly and the difference was clear in the surround, now everything is played on stereo. my configuration is ATV->LG EVO 55 -> SONOS system.

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. Go figure

 

[priitv8]

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.

How exactly do you see that it plays in DD5.1??
tvOS by default decodes all dolby audio (DD, DD+) internally and always outputs multichannel PCM (5.1, 7.1 or Atmos) from its HDMI output. So there is no such thing as Dolby Digital passthru on appleTV. It always outputs PCM. But it should be multichannel, not just stereo, for any DD5.1 or DD+7.1 content.
The only exception is when you set in Settings : Audio Format > Change Format and choose either Dolby Digital 5.1 or Stereo.
In that case, tvOS re-encodes the just decoded dolby audio back into DD5.1 and outputs the result over HDMI. This inevitably loses Atmos and 7.1 output otherwise possible with DD+ movies. If you chose Stereo, then you will get 2-channel PCM. That is why the menu option is called "change format".

Also see the last comment here

Apple TV Dolby Digital Plus 5.1 support - Apple Community

discussions.apple.com

and configurable Audio Format settings here

Change audio settings on Apple TV

On Apple TV, you can adjust audio settings to reduce loudness, enhance dialogue, send audio to other speakers and more.

support.apple.com

 

[Barrovian]

How do I know? Without sounding facetious, by listening to it coming out of the soundbar and rears and looking at the soundbar display. Before the update, and with the ATV sound settings on auto Dolby Atmos content played in Atmos. Sound came from all speakers and the soundbar display said Dolby Atmos. DD5.1 content played with sound from all speakers and the display shows Dolby Audio. Now, Atmos works but anything marked DD5.1 plays in left/right stereo. Nothing comes from any other speakers and the display reads just PCM. I have already tried the change format setting and it makes no difference. The only exception is ‘some’ content on the ATV’s You Tube app which do play in 5.1. Also, I can air play iTunes Media from my phone to the ATV and it plays in 5.1 but select the exact same content directly from the ATV and its stereo. All other devices are working. I’ve not changed anything on my setup. I used to get 5.1 sound and now I don’t. The only thing that has changed is the update to tvos18 so to a layman like me it’s got to have been the update. As to wether or not it’s PCM multichannel or Dolby Audio, I don’t really care. I just want my surround sound back.

 

[Barrovian]

How exactly do you see that it plays in DD5.1??
tvOS by default decodes all dolby audio (DD, DD+) internally and always outputs multichannel PCM (5.1, 7.1 or Atmos) from its HDMI output. So there is no such thing as Dolby Digital passthru on appleTV. It always outputs PCM. But it should be multichannel, not just stereo, for any DD5.1 or DD+7.1 content.
The only exception is when you set in Settings : Audio Format > Change Format and choose either Dolby Digital 5.1 or Stereo.
In that case, tvOS re-encodes the just decoded dolby audio back into DD5.1 and outputs the result over HDMI. This inevitably loses Atmos and 7.1 output otherwise possible with DD+ movies. If you chose Stereo, then you will get 2-channel PCM. That is why the menu option is called "change format".

Also see the last comment here

Apple TV Dolby Digital Plus 5.1 support - Apple Community

discussions.apple.com

and configurable Audio Format settings here

Change audio settings on Apple TV

On Apple TV, you can adjust audio settings to reduce loudness, enhance dialogue, send audio to other speakers and more.

support.apple.com

 

[Barrovian]

@priitv8, I've no idea why my reply has appeared so many times. I was replying on my phone and that's the result. Also this time I'm happy to accept it's user error as opposed to an Apple software update

 

[priitv8]

How do I know? Without sounding facetious, by listening to it coming out of the soundbar and rears and looking at the soundbar display. Before the update, and with the ATV sound settings on auto Dolby Atmos content played in Atmos. Sound came from all speakers and the soundbar display said Dolby Atmos. DD5.1 content played with sound from all speakers and the display shows Dolby Audio. Now, Atmos works but anything marked DD5.1 plays in left/right stereo. Nothing comes from any other speakers and the display reads just PCM. I have already tried the change format setting and it makes no difference. The only exception is ‘some’ content on the ATV’s You Tube app which do play in 5.1. Also, I can air play iTunes Media from my phone to the ATV and it plays in 5.1 but select the exact same content directly from the ATV and its stereo. All other devices are working. I’ve not changed anything on my setup. I used to get 5.1 sound and now I don’t. The only thing that has changed is the update to tvos18 so to a layman like me it’s got to have been the update. As to wether or not it’s PCM multichannel or Dolby Audio, I don’t really care. I just want my surround sound back.

I get your point.
Tried everything on my end. I would have assumed that the glitch is with the appleTV+ app itself on the tvOS.
But I am unable to reproduce the issue. All my sources (aTV+, Netflix, Disney+, Prime Video, YouTube, Computers app), play all multichannel formats (DD5.1, DD+7.1 and Atmos) as usual. Nothing has changed with the tvOS 18 update.
My only difference to your setup is, that all my sources are connected to AVR inputs and my TV is only working as a dumb, mute screen.
My principal concern with the widely advertised HDMI ARC setup is exactly this. It introduces additional unknowns to the signal path - the software inside the TV. And I do not want to deal with that additional source of compatibility issues.

 

[Barrovian]

Since, tvos18 I've tried so many different settings combinations and nothing has worked. Next step will be to try connecting the ATV to the soundbar directly and see what happens. It's just so frustrating that I've changed nothing at my end, save the update. It used to 'just work'. Now, it doesn't.

 

[Bobt_smf]

Since, tvos18 I've tried so many different settings combinations and nothing has worked. Next step will be to try connecting the ATV to the soundbar directly and see what happens. It's just so frustrating that I've changed nothing at my end, save the update. It used to 'just work'. Now, it doesn't.

As stated above in this thread, the issue is you have a first generation 4k aptv, the update broke the Dolby 5.1 output from the device. Don’t waste your time making changes, it is not a settings or connection issue , just wait for Apple to fix it in an update.

 

[priitv8]

As stated above in this thread, the issue is you have a first generation 4k aptv, the update broke the Dolby 5.1 output from the device. Don’t waste your time making changes, it is not a settings or connection issue , just wait for Apple to fix it in an update.

My aTV 4K is also 1st Gen, bought 2017.
It plays multichannel, as usual.
I would steer clear of HDMI ARC, whenever possible.

 

[Barrovian]

As stated above in this thread, the issue is you have a first generation 4k aptv, the update broke the Dolby 5.1 output from the device. Don’t waste your time making changes, it is not a settings or connection issue , just wait for Apple to fix it in an update.

Hi @Bobt_smf. Thanks. My gut feeling is that it's something on Apple's side. When I first got my TV & soundbar I noticed that Dolby Atmos was fine with Auto, Atmos Enabled but that anything else was two channel PCM stereo. Then, I was able to use the 'change format' setting to force DD5.1 for non Atmos content. That worked well. A couple of months back I reverted back to 'Auto, Atmos Enabled' and DD.5.1 worked so I left it. It was fine until tvOS18 now not even using the change format trick works. I hope you're right that it's a 1st gen issue, but as @priitv8 says above, he has a 1st gen and its fine so who knows. Thanks for taking the time to reply though, it's appreciated.

 

[bag of kittens]

I'm having the same exact issue - 1st generation Apple TV 4K. Was getting DD5.1 before, and after the TVOS update, Sonos Beam 2 is only showing Stereo PCM even though the Apple TV 4K is showing DD5.1.

Have tried resetting settings on the Apple TV, Sony Bravia, and Sonos Beam 2 and this is clearly an Apple issue.

 

[Barrovian]

I'm having the same exact issue - 1st generation Apple TV 4K. Was getting DD5.1 before, and after the TVOS update, Sonos Beam 2 is only showing Stereo PCM even though the Apple TV 4K is showing DD5.1.

Have tried resetting settings on the Apple TV, Sony Bravia, and Sonos Beam 2 and this is clearly an Apple issue.

The more I think about it, the more I think the update has broken the change format option. I remember some time ago that that was the only way I could get DD5.1 was by using the Change Format and selecting DD5.1, then re-enabling Atmos as and when. Then, one day everything seemed to work seamlessly so I left it on Auto. And that worked until tvOS18 but no even the Change Format doesn’t work. It’s still just stereo despite what the ATV says.

 

[donrb5]

I have a 1st Gen and 2nd Gen Apple TV 4K. Dolby 5.1 is not working on either one.

 

[Airik]

I am also experiencing the exact same issue. With the tvOS 18 update, Dolby Atmos continues to work fine, but Dolby 5.1 seems to now only work randomly in some apps (Plex is the only one I've noticed so far), and comes out as stereo PCM everywhere else (notably anything in the purchased movies/TV library and pretty much every streaming app). I've even updated to today's latest tvOS 18.1 developer beta and the issue still remains. It has to be an Apple bug.

 

[Barrovian]

I had a play this morning and connected my Apple TV 4K 1st Gen tvOS18.1 beta to my LG SN9YG (plus wireless rears) via the HDMI connection on the soundbar. Unfortunately it made no difference. Atmos is fine, but everything else is PCM 2.0. No PCM multichannel and no DD.5.1 even though the Change Format option shows DD.5.1 selected. Reconnected the Panasonic 4k blu ray player to the soundbar and it plays Atmos, DTS X and DD5.1. So, it's got to be tvOS 18 (& 18.1 beta) that's broken audio for the Apple TV. Nothing else to do but keep bunging in feedback to Apple and wait I guess. Frustrating doesn't come close. I (and I'm sure many others ) have invested a lot in Apple movie purchases, and at a stroke those purchases have effectively been downgraded in quality. At least they can't remove DD from a Blu ray or DVD.

 

[priitv8]

The more I think about it, the more I think the update has broken the change format option. I remember some time ago that that was the only way I could get DD5.1 was by using the Change Format and selecting DD5.1, then re-enabling Atmos as and when. Then, one day everything seemed to work seamlessly so I left it on Auto. And that worked until tvOS18 but no even the Change Format doesn’t work. It’s still just stereo despite what the ATV says.

You are spot on here!
I tried the change audio format on my setup and no matter whether I select Stereo or DD5.1, tvOS 18 outputs always PCM2.0.

 

[Murray_7891]

Having same issue after installing tvOS18. Its more annoying for me as ive literally just got rid of sky to make apple tv my main box for viewing content through apps such like disney, netflix, prime etc.

Running a LG G3 with LG soundbar, apple tv 3rd gen. Everything was running smoothly on everything from purchased movies like topgun maverick, to all my apps.

Noticed there was no sound whilst navigating in the netflix app. Went striaght onto youtube played something still no sound. I tried messing about with audio settings on the apple tv to no avail. I went onto tv and switched over to optical out + tv speakers i get sound then and with just tv speakers.

Soon as i switch over the tv over to HDMI eArc the tv displays the no sound icon. This is highly annoying. Whats even more a pain is that i have no other way of testing if its my soundbar. As i have 2 apple tvs and the one in my bedroom is also tvOS 18. Dont have any consoles to run a blu ray through.

I may try factory resetting them in hope that it reverts back to the last tvOS. Really hope apple release a fix (checking daily atm).

 

[Barrovian]

Having same issue after installing tvOS18. Its more annoying for me as ive literally just got rid of sky to make apple tv my main box for viewing content through apps such like disney, netflix, prime etc.

Running a LG G3 with LG soundbar, apple tv 3rd gen. Everything was running smoothly on everything from purchased movies like topgun maverick, to all my apps.

Noticed there was no sound whilst navigating in the netflix app. Went striaght onto youtube played something still no sound. I tried messing about with audio settings on the apple tv to no avail. I went onto tv and switched over to optical out + tv speakers i get sound then and with just tv speakers.

Soon as i switch over the tv over to HDMI eArc the tv displays the no sound icon. This is highly annoying. Whats even more a pain is that i have no other way of testing if its my soundbar. As i have 2 apple tvs and the one in my bedroom is also tvOS 18. Dont have any consoles to run a blu ray through.

I may try factory resetting them in hope that it reverts back to the last tvOS. Really hope apple release a fix (checking daily atm).

Welcome to the club that no one wants to be in If you've not done so already can I suggest you send feedback to Apple via their support hub. The more of us that moan to them, the better.

 

[Windh]

Same issue here. I use a splitter to get the optical audio needed for my system. After the update, 5.1 audio only works from the YouTube app and Infuse apps.

Seems to be an issue only for users that don't use HDMI straight into their receiver...

They need to fix this ASAP...