Question

Sound cutting in and out on Sonos Arc after playing Dolby Atmos content on Apple TV 4K


Sound cutting in and out on my Sonos Arc after playing Dolby Atmos content on Apple TV 4K 

I’ve had my Sonos Arc and Sub Gen 3 for about two weeks now and I’m very satisfied with the sound quality, but I’m having some very annoying issues with audio cutting in and out… 
I have the latest LG OLED TV, a LG GX (same as the CX, just wall mounted). The only two boxes I have hooked up to my TV is an Apple TV 4K and a PS4 Pro, but I’m having sound issues on my Apple TV.
Before I explain the problem, yes, I’ve pretty much done all the troubleshooting I can do. Plug everything in and out, check that the cables is properly connected, updated everything, the Arc, TV and Apple TV, everything should be up to date as I’m writing this post. 

 

Okay, so here’s the issue, with a half ish solution. 

My issue: 
If I play any content that supports Dolby Atmos on iTunes, Apple TV+, Netflix etc. and try to play some music through the Apple Music app or watch any video on YouTube on my Apple TV after that, the audio cuts in and out every other second. This even happens after playing a Dolby Atmos movie on iTunes and when I go back to the movie menu, the audio starts to cut in and out. It doesn't help to turn the TV and Apple TV on and off and it doesn't help to just restart the Apple TV itself. 

 

The half ish solution:

The only fix that I found that worked, is to play a movie that is in 5.1 after playing Dolby Atmos supported content. If I do that and then go into Apple Music or YouTube, the audio is fine and it doesn't cut in and out every other second. 

 

The issue: 
So it seem like the Arc might have an issue going from Dolby Atmos straight over to stereo sound. But going from Dolby Atmos to 5.1 or from 5.1 to stereo works just fine.
It work perfectly the other way around, from stereo to 5.1 or Dolby Atmos. The only thing I hear then is a little loud zippering or buzzing sound, but I guess that’s just because the Arc is switching the sound receiving signal? If that zippering / buzzing sound shouldn't happen, let me know. 

 

The funny part: 

Here’s the the funny part though, if I play something in Dolby Atmos on my Apple TV and after that play a YouTube video on the built-in YouTube app on the TV, the audio is fine. Same if I AirPlay music to the Arc. So I’m a little unsure if there’s something that has to be fixed from Sonos’s end or Apple’s? 

I’m seeing a lot of people on here tags @Ryan A  and @Kyle A, so I’m gonna do that too, seeing as they come up with a lot of good answers. 

If anyone else has had similar issues, let me know.


102 replies

Userlevel 1

Great news! LG is working on a FIX for this issue:

“We are aware of a compatibility issue related to the Dolby ATMOS and Apple TV. We have a temporary workaround to have the sound work, while we work on developing the fix.

We will need to change a few settings for the workaround. On the LG TV go to:

-  Settings → Sound → Additional Settings → HDMI Input Audio Format → HDMI “PCM” Setting

On the Apple TV we will need to change the following:

-  Settings → Video and Audio → Audio Format → Dolby Atmos “Off” Setting

A fix for this issue should be out in December. Please stay tuned for updates.”

 

https://lgcommunity.us.com/discussion/14247/cx-atmos-audio-bug-with-apple-tv-4k

Userlevel 5
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Hi folks, thanks for reaching out with the Sonos Community! Let me share these threads that may be helpful for some of you. 

https://en.community.sonos.com/troubleshooting-228999/no-dialog-through-arc-from-apple-tv-4k-6847888

https://en.community.sonos.com/home-theater-228993/did-ios14-tvos14-quietly-bring-atmos-audio-to-airplay-2-6848270

We will be adding Multi-Channel LPCM support to Arc as part of a future software update. We don’t have exact timing to share at this point and will update this thread as well when we do.

Please let us know if there’s anything else we can help you with. We and the community are always here.

Userlevel 1
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WOW

LG just fixed the issue today they pushed a new firmware.

 

03.21.09

 

fully resolved the Dolby Atmos issues when switching from stereo to Atmos back to strep on Apple TV.

 

So happy, after months of this not working!

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I’m totally staggered by the lack of action on the part of the three parties to pull together and get this sorted out. 
 

LG GX 65 (tested with and without eARC)

AppleTV 4K (tested with TVOS 14 and 14.2)

Sonos Arc + SL + Sub
Brand new AudioQuest “Coffee” 8K compliant HDMI cabling

These are all supposed to be “premium” offerings, yet the issue has persisted ever since the Arc launch. 
 

Rebooting the TV, or the Arc usually resolves the issue. Rebooting the AppleTV does not always, unless you physically remove power. 
 

I also experience the Arc not waking up semi-regularly, have never been able to get surround sound from my Nintendo Switch Dock. Sonos, please get with LG and work this out, it’s awful for both your brands. 

Same here - Arc/CX/ATV4K. Just waiting on software updates I guess 

Update for my issue with in built apps. I had digital sound out set to pass through. Putting it back to auto seemed to fix the issue.

Did the lastest software update from Sonos fix this? There was an update to support multi channel earc in these release notes

 

I’m away this weekend but will upgrade once I get back.

I’ve updated my sonos app to the latest version and the issue still occurs

I’m also still having all of the described issues after the LPCM update

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Frustrating that this firmware is not widely available if it fixes the issues.  I am on 3.11.30 and no updates available.

It’s easy to download from the Korean website. 
https://www.lgservice.co.kr/search/driverSoftTotalSearchPage.do?searchKeyWord=2020%EB%85%84%20LG%20%EC%98%AC%EB%A0%88%EB%93%9C%20AI%20%EC%B5%9C%EC%8B%A0%20%EC%86%8C%ED%94%84%ED%8A%B8%EC%9B%A8%EC%96%B4_OLEDxxCXX_GXX_O20)&oneCateCode=1005&twoCateCode=D002795

 

select the first option All Red = OLED

I saw a couple of people on the LG forum did this and said it did not fix the issue.  Can you verify that it worked for you?   I am just a little leery of installing a potentially unsupported firmware, and then have something else go wrong on a $3500 TV and not get support from LG.    
 

granted I’ve only had the update for a day but so far so good! The soundbar going out for 2-3 seconds issue has not popped back up!
 

The Apple TV issue with atmos and stereo sound cutting in and out has been resolved for sure  

 

I can also confirm having the exact same issues witch ARC/77CX/Atv4K. Sound drops in/out after playing Dolby Atmos content on AppleTV. And sometimes the loud “zip” sound when changing input.

@okgrongstad @Buggses @AjTrek1 

Same issue on my brand new LG CX 65”, Arc and Sub (Gen 3).

Switching to 5.1 on Apple TV and playing all Atmos content on built in apps (unfortunately no native HBO Max app yet) seemed to resolve it.

Do we know if this is an LG issue / Apple issue / Sonos issue? That high pitched zip sound was crazy. I also got a couple of errors in the middle of watching content from Apple TV Netflix app. Could NOT replicate when I removed Sonos from the equation.

Anyone at Sonos looking in to this? Having everything coming out of Apple TV would be preferable. Much nicer interface than LG.

 

 

@okgrongstad

Had the same issue and same setup, however, I was able to replicate the problem without the ARC connected.  I had only the Apple TV connected to HDMI 1 and nothing else connected.  Using the internal speakers with Atmos enabled also caused the issue for me.

I’d be interested to know if you can recreate the issue without the ARC connected.

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My config:

LG CX 65 - eARC enabled

Apple TV 4K - HDMI 1

Arc - HDMI 2

Exactly like Hamzah

Same issues like everyone else

Please Sonos sort this out !

Userlevel 2
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This is apparently fixed on the LG CX with new firmware (3.21.09), only available in some regions at the moment though.

 

Confirmed, this is fixed in LG CX firmware 3.21.09 :)

@phivs

For me it’s down to two devices either the LG TV or the Apple TV 4K.  I exchanged the TV due to faulty ports (hardware problem) and can still replicate the choppy sound without the ARC soundbar connected.  I have the HDMI 2 port completely disconnected with sound going to internal speakers (not optical + internal speakers) and Atmos enabled.  On the Apple TV device I have match content and range with the sound set to auto,  Atmos available.

 

To replicate the issue, I go into the Apple TV app on the Apple TV 4K plugged into HDMI 1 and watch the trailer for Greyhound.  Once sound starts playing I back out of the trailer and immediately notice navigation sounds start cutting in and out.  Then I open YouTube and play a video with stereo audio and the sound remains choppy until rebooting the TV.

 

I have contacted LG support with the issues.

@okgrongstad

Had the same issue and same setup, however, I was able to replicate the problem without the ARC connected.  I had only the Apple TV connected to HDMI 1 and nothing else connected.  Using the internal speakers with Atmos enabled also caused the issue for me.

I’d be interested to know if you can recreate the issue without the ARC connected.

Since you’ve verified you can reproduce w/o the Sonos Arc, I recommend reporting to LG support as well as it seems like they broke something in firmware 3.10.20.

Same issue here with CX, Appletv 4K, and new arc arriving today. 

@phivs

For me it’s down to two devices either the LG TV or the Apple TV 4K.  I exchanged the TV due to faulty ports (hardware problem) and can still replicate the choppy sound without the ARC soundbar connected.  I have the HDMI 2 port completely disconnected with sound going to internal speakers (not optical + internal speakers) and Atmos enabled.  On the Apple TV device I have match content and range with the sound set to auto,  Atmos available.

 

To replicate the issue, I go into the Apple TV app on the Apple TV 4K plugged into HDMI 1 and watch the trailer for Greyhound.  Once sound starts playing I back out of the trailer and immediately notice navigation sounds start cutting in and out.  Then I open YouTube and play a video with stereo audio and the sound remains choppy until rebooting the TV.

 

I have contacted LG support with the issues.

That’s some fine troubleshooting there!  I wonder why more people aren’t experiencing as I’ve only heard of this issue from Arc users.  Again, I’ll reiterate that this was NOT an issue until LG firmware 3.10.20.  Earlier firmware versions of the LG CX did not have this issue when connected to the same equipment (LG CX, Arc, ATV4K).

 

I suspect this has to do with the ATV’s encoding of Atmos vs other devices.  The Apple TV sends the Atmos signal in a MAT format of Dolby Digital.  When playing Atmos content through my Xbox one, there is no stuttering of stereo content.

Hello @okgrongstad 

I saw you were reporting issues with your Sonos Arc and wanted to say I have been having similar issues even though I have a different setup/device and just wanted to add some information.  Thanks for taking the time in posting your issue with all the details.

 

Sound Cutting in and out:

The issue I have been having with my Sonos Arc is where the sound cuts out for about ¼ a second and comes right back.  I had a similar issue before with my Sonos Beam, although I don’t recall it happening as frequently as it is now.

Setup:

TV: LG OLED C8

SYSTEM: Sonos Arc paired with two rear Sonos Play:1 for surround sound speakers.

STREAMING DEVICE: Nvidia Shield Pro (2019)

 

My issue: 
While I need to do further testing to see if my issue is related to having Dolby Atoms streams, I have been experiencing the sound cutting in and out on my Sonos Arc during playback.

Here is a recording of what I hear:

The skips you hear are exactly what I hear (this is not an issue with the recording).  Apologies for the intense movement and sound of the recording, I was using ‘Dark’ on Netlfix.

 

Testing/Information

NVIDIA: I have reached out to Nvidia regarding the issue and they had me replace my HDMI cable and even sent me a new Nvidia Shield but the audio issue continues.  I am currently using Monoprice 8K cables (overkill I know).  My Shield goes directly to my TV via HDMI and the Sonos Arc is connected to my LG OLED TV via the ARC port using the HDMI cable that came with the Arc.

LG: I have reached out to LG regarding my TV.  I was able to replicate the issue while the tech was there and he ended up replacing my Main Board within the TV.  His fix was simply a guess as to what was causing my audio issues, my TV passed all the tests that he did prior to him replacing the main board.  He did mention that the sound issue seemed to happen more often when there was lots of motion on the TV or when the sound was ‘swelling’.  While I agree with that assessment, I have also heard the issue happen with simple cartoons or TV shows that are mostly just dialog (more to come on that below).

Sonos: I have reached out to Sonos who pulled multiple diagnostics sent to them and said they saw nothing wrong with my Sonos Arc and any connections.

 

Test: I used the opening sequence of “Dark’ on Netflix (Season 2, Episode 1 from the 05:15 mark to about 15:00 in). I have 4K, Dolby Vision, and Dolby Atmos playback enabled on Netflix when I do this.  Dolby Vision is also turned on within my Nvidia Shield.  I play said episode and the time frame on my Nivida Shield and without fail will get the audio to ‘skip’ (as described above).  The times when the skip happens is not consistent.  It can happen only once during playback or multiple times.

I played the same episode on my Fire TV (4K).  This device will play the episode in 4K but with only 5.1 sound being sent.  No issues noticed or recorded in multiple playbacks.

I played the same episode directly from Netflix within my LG TV OS.  Playback showed the signal coming in at 4K, HDR, and Dolby Atmos being on.  No issues noticed or recorded in multiple playbacks.

No other audio device to my TV and thus to my Sonos Arc causes this skipping issue, I have also had my PS4 and Nintendo Switch connected to my LG TV and the Sonos Arc worked just fine. I will add it doesn’t matter what application I am using within the Nvidia Shield to hear the audio skip.  I have heard the issue simply watching Family Guy on Hulu, watching Toy Story on Disney+, and watching New Girl on Netflix (within the Nvidia Shield).

 

Conclusion:

While I do believe the issue seems to be related to my Nvidia Shield Pro given the above test.  It has been a pain to try and narrow down every single connection and issue to try and rule them out.  I do find it odd this is my second Nvidia Shield (they replaced my first via RMA for free) and the issue continues.  They are going to try replacing it one more time, but can’t seem to find an issue within my Nvidia Shield after sending feedback from my unit directly to them.  I will say the issue ‘seems’ to happen more with Dolby Atmos content, but again I have heard the issue come up while simply playing Family Guy on Hulu which doesn’t have Atmos. This issue also happened with my Sonos Beam before I upgraded my Netflix account to 4K and allow for Dolby Atmos.  At that time my Sonos Beam was connected to my LG TV via the optical adapter.

 

Playing music from Alexa or even directly from the Sonos app has no audio issues either.  Spotify, Apple Music and Pandora all work and sound great without issue.

 

Recently Development:

I spoke with a Sonos customer service rep today who told me the audio issue I was describing could be due to the fact my LG OLED C8 only has a HDMI (ARC) port and not eARC since this TV is just shy of being 2 years old.  While I understand this, I believed that on my TV specifically the ARC port WOULD allow Dolby Atmos.  There is not a lot of information, but from what I could find on some other forums was this: “ The C8 should deliver Atmos but as a lossy Dolby Digital+ stream as opposed to the lossless Dolby TrueHD you find on blu-ray and 4K blu-ray. You need eARC on both the TV and the receiver/soundbar for lossless audio.”

(EDIT)Further Add:

Sonos’ own website states HDMI ARC should work fine with the Sonos Arc.

https://support.sonos.com/s/article/4844?language=en_US

 

Hope any of that information helps.  Just wanted to share what I have been experiencing as well, even though I understand a few different things are at play.

 

FYI, this is definitely not a SONOS issue.  Unplugged the HDMI ARC to the Sonos and you’ll see the the LG tv does the same audio stuttering.  This is an LG tv and Apple TV issue.  It’s just that so many people have this LG CX, Apple TV and Sonos combo that people naturally blame the speaker system.

Userlevel 4
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Hello, I’m writing from Colombia.  I have the same problem. LG CX + Apple TV 4K + Sonos ARC + 2 Sonos one LS. LG firmware 03.11.30 no updates 

Can you get the new 3.21.09 firmware, that seems to have fixed the issue you have, not had the issue since installing this firmware on my cx, but did only install it yesterday.

Although this new firmware does dim HDR game mode, and LG have said they will be fixing that in another firmware in the coming weeks, so if you game on the CX you might want to wait for the next firmware. 

TV: LG CX77

Streaming device: Apple TV 4k 
 

I’m having the same issues with sound stuttering after changing from Atmos to non-Atmos sound content, as well as the loud zipping sound when starting Atmos supported content. None of these issues are present when playing content on native apps on the tv, only when accessing content through the Apple TV 4K. Thanks so much for the updates on this issue, hopefully Sonos releases a patch to read LPCM sooner than later.

Same issues here too - Arc/CX/ATV4K

Did the lastest software update from Sonos fix this? There was an update to support multi channel earc in these release notes

 

I’m away this weekend but will upgrade once I get back.

I’ve updated my sonos app to the latest version and the issue still occurs

I completely agree.   He said that the software versions cannot be reverted so the only way would be to exchange the device for a new one that comes with beta software.    I’m going to watch some Monday night football today but I’m taking it back to Best buy tomorrow for an exchange so I’ll let you know if it works tomorrow.    

Same issue, same setup:

LG CX 65 - eARC enabled

Apple TV 4K - HDMI 1

Arc - HDMI 2

Any sound format after playing an Atmos track skips in/out every half second.  Disabling Atmos on Apple TV seems to be the only “fix” at the moment 

This is definitely not how I expected to enjoy all 3 of these “premium” products

What’s strange is once the audio starts skipping, if I disconnect the Arc and just play sound through the LG speakers, the audio still skips.  To me that indicates the Apple TV is at least somewhat to blame?

That said, before I had the Arc the Apple TV and LG CX had no issues by themselves with all sound playback, including decoding Atmos.

Has anyone had better results with different streaming devices?

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