Question

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

  • 2 August 2020
  • 74 replies
  • 6303 views

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.


74 replies

Userlevel 4
Badge +12

Hi @okgrongstad, thank you for reaching out and welcome to the community.

Thank you for taking the time to troubleshoot this. 

To confirm that the issue only occurs when using the Apple TV; I would you to take a diagnostic in the Sonos app when you encounter the issue.

Setting > Help & Tips > Submit Diagnostic and reply with the confirmation number.

For the buzzing, that shouldn’t happen whenever switching audio sources. I recommend calling our Phone support as this could be a hardware issue. 

If that’s the case, they’ll have options to address the issue; if they find something wrong with the Sonos Arc. 1 800 680 2345 Monday to Friday 10 am to 9 pm ET.

To further isolate the issue, you can also check if the audio cuts out during music playback with the Sonos app, and with an optical connection to the TV.

If you have other concerns, feel free to reach out.

Userlevel 7

Hi @okgrongstad 

AppleTV (ATV) sends audio in LPCM by default. The Sonos Arc cannot yet interpret that codec. Make sure you change the audio in ATV under Settings > Audio/Video > to Dolby Digital 5.1. That may help. If you have already done so then please follow the advice of @Kyle A

Note: If you make the change and the problem persists you’ll need to submit another diagnostic within 10 minutes of the next occurence.

Cheers!

Hey @Kyle A here’s the diagnostic number I got when the issue happened again: 1422262013

I wouldn’t call it buzzing, more of a hard zip sound, that’s best way I can describe it. It happens sometimes if I’ve watched something on YouTube (normal stereo sound) and then turn on something in Atmos, there’s a little zip sound, should this happen? If not I’ll call the support number. 

This thread is marked as answered, but I don’t think that’s correct yet. 

Userlevel 4
Badge +12

Hi @okgrongstad, thank you for the update.

I checked the diagnostic, it shows the same errors as the other Arc diagnostics.

The TV audio signal keeps cutting in and out intermittently. It’s using the HDMI connection. 

The Arc is also receiving PCM-silence from the TV. Check the Apple TV settings as @AjTrek1 suggested.

For the buzzing, it shouldn’t buzz when switching audio sources.

I would recommend calling our Phone Support; if you still encounter issues after changing the Apple TV settings.

If you have other concerns, feel free to reach out.

 

 

Hi @Kyle A

If I use the setting @AjTrek1 suggested, will I still get Dolby Atmos sound on the content that supports it? I’ll try it out regardless. Do you know if this eventually will be fixed in an upcoming patch? 
 

I say this even before I try it out, but I’m 99% sure that the short hard zip or the short buzzing sound won’t happen if I change the settings as mentioned above. This zip sound only happens sometimes when it goes from stereo to 5.1 or Dolby Atmos. 

Userlevel 7

Hi @okgrongstad 

Changing the audio setting on your ATV as I suggested will make Dolby Digital 5.1 the default audio for all ATV programming that supports it. If the material streaming over ATV is stereo that’s what you will hear instead. 

Audio from other sources will not be affected. Your TV will process whatever audio it understands.

Cheers!

But on the Apple TV you turn on the setting called “change format” and set it to Dolby Digital 5.1 there is a message that says “Audio will be re-encoded as Dolby Digital 5.1. Turn off Change Format to improve audio quality and enable Dolby Atmos.” Does the TV bypass that then @AjTrek1
 

Update: I tried to change the setting, and when I tried to play something in Atmos it didn’t play in Atmos, could it be that Sonos don’t support LPCM yet? 

Userlevel 7

Hi @okgrongstad 

It’s not the TV. ATV is sending the formatted audio. All audio from your ATV process as DD5.1 if that is what the audio was recorded in. Your TV is only processing what it receives. If Dolby Atmos is sent from another source like NetFlix that’s what your TV will process if it is capable of doing so. I hope this answers your question. Feel free to ask again if not.

Sonos does not support LPCM yet. An update is said to be pushed out later. 

Cheers!

Hi @AjTrek1, thanks for responding so fast. 
When I changed the settings on Apple TV to Dolby Digital 5.1 and tried to play a movie in Atmos on iTunes, it didn’t play in Atmos, I couldn’t see the Dolby Atmos logo in the Sonos app either. So if I understand this correctly, if I use the setting that you suggested, all the audio that comes out from the Apple TV will either be stereo or 5.1, and won’t support Atmos? But if I use the build in Netflix app on the TV that will be able to play in Atmos? 

Hopefully the LPCM patch comes out soon! 

Userlevel 7

Hi @okgrongstad 

You are correct. Just remember that ATV can send Dolby Atmos in LPCM format. It’s just that the Arc at present cannot process LPCM codecs. 

Hi @AjTrek1, so the best solution would be to watch Atmos content on the built in TV apps until the LPCM patch comes out, and watch stereo and 5.1 content on the Apple TV? 

Hopefully the patch comes out soon, the user experience is so much better on the Apple TV and it’s so much better to play everything through one box. 

Userlevel 7

Hi @okgrongstad 

You are correct.

@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.

I have this same issue and same TV.  I’ve seen others report this on AVSForum and the LG Community.  For me, the issue started with the CX firmware 3.10.20 as the combination worked perfectly with earlier firmware versions.  The issue can also be remedied by turning the TV off then back on and the issue will also stay if you switch the audio to the TV’s internal speakers.

 

 

@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.

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.

 

@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.

 

 

@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.

Userlevel 7

Hi All

This issue as it relates to Sonos and AppleTV depends upon where you want to place the blame.

  1. You could blame Sonos for not (at launch) equipping the Arc to decode LPCM. It’s said that the Arc will decode LPCM upon a later update.
  2. You could blame AppleTV for using LPCM as the primary base codec to carry Dolby Atmos.
  3. So take your pick….Sonos or AppleTV...who’s to blame :thinking:  I have my opinion but I’ll let you draw your own conclusions. However, I’ll leave you with this:

You manufacture high performance cars. I manufacture high performance tires. Should you manufacture cars to work with my tires or should I manufacture my tires to work with your cars. Oh BTW their are any number of tire manufacturers vying to be named as OEM for your cars.

I’d like to read your answer to the above. 

HINT: There many soundbar manufacturers to choose from.

 

Cheers!

@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.

Hi all.

I own an LG 77CX, Apple TV 4K with Sonos Arc and experienced the exact same audio dropout issues after watching Dolby Atmos content on it.  My brother owns an LG 55CX, Apple TV 4K with Sonos Playbar and experienced the same audio drop out on Dolby digital content until we selected the option to change the  audio format in the Apple TV audio settings.  This is fine with the playbar as it only does Dolby digital but selecting this option with the Arc will disable Dolby Atmos.

This issue does not occur using my nvidia shield or when I used my previous TV, which was a Samsung (connected via optical cable).
So looks like this is an issue with the Apple TV and LG CX not the Arc but hopefully once Sonos update the Arc to play lossless PCM this issue may be resolved. 

I have the same issue with the loud “zip” sound when changing audio formats on ATV with Sonos Arc and LG CX tv. I also get that same sound on Xbox One X when I first turn it on. I hope this sound isn’t damaging my speakers! I guess I’ll avoid the ATV and hope it’s fixed when LPCM gets added. And keep the volume low when turning on Xbox. 

I’m having both issues mentioned here: the loud “zip” sound and the random interval stuttering with my Apple TV 4K, Sonos Arc, and LG CX (2020). The “zip” sound happens with my Xbox One X too. Any solutions?

Same issues here too - Arc/CX/ATV4K

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