Surround Sound Issues

  • 5 April 2022
  • 4 replies

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Last night while watching the Peacock app, via Apple TV 4K (2021), I noticed the sound for the show was predominantly (maybe entirely) coming only from the 2 rear surrounds (symfonisks). I waited to see if this would change in the next scenes but it did not.

(FYI, connected via eARC input and audio set to HDMI ARC - Passthrough, and additionally eArc selected on the TV. Have had no problems like this since my initial hook up over a year ago)

But I decided to “re-connect to TV while on the Sonos Input of the TV. Came back to the app, and now the sounds does seem to be coming from the Arc, but now nothing is coming from the surround speakers. Although the App shows “PCM Multichannel 7.1” the sound is surely Stereo (or limited to the Arc).

I tried multiple apps, and regular TV, but the situation is the same. 

Any advice? 


The only other time I recall main dialogue coming from the 2 surrounds was during sequences of the Amazon Original “Lucy and Desi”. I actually thought it was unique to hear dialogue in a quiet scene come only from the nearby rear speakers, it actually seemed intuitive.

Oddly enough, we’d noticed other sound issues (not Sonos related) while playing this specific title on Peacock (Miami Vice season 1 - where I read this season’s Blu-Ray package release by Mill Creek Entertainment was plagued by audio issues in the season 1 disc(s), which were remedied by a re-release of the disc(s). It seems Peacock is using the bad audio from the original BD release for season 1 on Peacock). 


Best answer by GuitarSuperstar 5 April 2022, 20:15

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Userlevel 7

Do you have an LG TV?

Try unbonding the SYMFONISK speakers from the Arc in the Sonos app and unplugging the Arc and surrounds from power for a couple of minutes. Then reboot your router. Then plug the Arc and surrounds back into power, wait until they are connected to the network, and add the SYMFONISK speakers as surrounds to the Arc again.

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Yes I do have an LG TV - CX model. 

Thanks for the tips. Let me try and will get back with results.

Userlevel 7

The LG CX is known to have issues with LPCM audio from the Apple TV 4K. Rather than getting the correct “Multichannel PCM 5.1” audio from the Apple TV, the LG causes the Arc to play “Multichannel PCM 7.1” audio which seems to cause some audio problems with some LG users.

With non-Dolby Atmos content, you might want to experiment with changing the audio settings on the Apple TV. If you set the Change Format setting to ON and set the Audio Format to Dolby Digital you might get more desirable results. 

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Thank you - I was able to remove and re-add the surrounds to the TV Room set up and now have them working again. 

At first try the finalization of adding surrounds via Sonos App didn’t work, and the app mentioned re-starting the network. I couldn’t take the network down but I noticed one surround speaker was not showing as a connected device in the Wi-Fi list. On 2nd attempt at finalizing the surrounds the system completed the connection process.

I think when I re-connected the sound system to the TV last night I may have lost the surrounds in the process … when adding the 2 surrounds back just now, each one was showing to be in its own TV Room (2 and 3), while ARC and sub were in just the TV Room. Anywho, all good now.

Noted on the Apple TV 4K PCM issues. I remember reading about this when I set up the system last year. I can’t recall if the Sonos app ever ever displayed Dolby Digital 5.1 or other Dolby formats besides Atmos. I know the App displays correctly for disc-based and direct from TV content.

I’ve preferred to keep the Apple TV sound format setting on Atmos, and let chips fall where they may, assuming that although the app might say Multichannel 7.1, the feed is correctly distributing either Stereo PCM or 5.1 surround as necessary.