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Avid Contributor III
May 6, 2020
Answered

Multichannel PCM on Arc

Are you really not supporting multichannel PCM on the newly announced Arc?

Why? It’s not a licensing issue this time.

It seems like there is always something missing with your home theater products.

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Ditte
DitteAnswer
November 10, 2020

Hi all,

We hear you. With a software update today, Arc now supports multi-channel LPCM, bringing new immersive sound experiences for gaming, Blu-ray discs, and more. To get support for multi-channel LPCM on Arc, download the latest Sonos S2 update from the app store and then update your system in the Sonos S2 app. After updating the app, go to Settings > System > System Updates > Check for Updates.

All the best,

Ditte

328 replies

Headliner II
February 20, 2021

@ledzep1 He played a 5.1 test sound, it doesn’t necessarily mean the BR player was outputting a 5.1 signal. The BR player could be having the same issue as our PS4s/5s where for whatever reason it recognizes Arc as 7.1, outputs a 7.1 signal and Arc doesn’t convert to 5.1  If he can manually set the BR player to 5.1, that would eliminate that variable.   

In my experience across 3 devices now, devices outputting LPCM 5.1 show properly in the Sonos app as PCM 5.1. I think it may be your TV model/settings that is the problem there. What are your pass through settings set to?
 

There is still definitely something odd though with devices thinking Sonos is 7.1, I think. 
 

My PS5 when forced to output uncompressed 5.1, shows correctly in app as 5.1. When allowed to pick itself on “auto” it shows 7.1 in the app. 
 

Did you try that ATV 5.1 test app? 

 

Need to get around to trying the test app, on my series x if I elect uncompressed 5.1, the sonos app says its outputting as multichannel pcm 7.1.

I know others have encountered the same, so its not just me, perhaps it is the LG CX, I have audio set to passthrough with eARC on.

Headliner II
February 20, 2021

@FishyD I tried test app and it reports multichannel 7.1.

Lyricist III
February 20, 2021

@ledzep1Interesting. That is a DD 5.1 signal and if your ATV is set to “auto” in the sound settings, is decoded by ATV and output in LPCM. That pretty much narrows this particular issue to LG, that is the only variable here. With this exact same test, my Sonos shows PCM 5.1. I would just make sure your ATV sound is set to “auto” and shows in the description that ATV will output in multichannel PCM. 
 

I wonder if others having this problem have LGs. 
 

On my Sony, same settings. Pass through and eARC on. Do you have an “auto” setting on your TV in the audio Arc pass through settings? Maybe try that and see what happens. 

Headliner II
February 20, 2021

@ledzep1Interesting. That is a DD 5.1 signal and if your ATV is set to “auto” in the sound settings, is decoded by ATV and output in LPCM. That pretty much narrows this particular issue to LG, that is the only variable here. With this exact same test, my Sonos shows PCM 5.1. I would just make sure your ATV sound is set to “auto” and shows in the description that ATV will output in multichannel PCM. 
 

I wonder if others having this problem have LGs. 

Yep it’s set to auto, yes others have this issue, I’ve got responses from others on another forum and there are a few threads on Reddit reporting same, so seems like a LG issue but It seems to have got mixed up with that other LPCM audio issue on here that Sonos are investigating.

 

Lyricist III
February 20, 2021

100%.  There appear to be 2 separate (possibly related) LPCM issues here. This one you and others are having where on LGs, an actual 5.1 signal is somehow showing as 7.1 and the issue where devices like PS are auto recognizing Sonos as 7.1 and Sonos isn’t converting that 7.1 down to 5.1. 

Lead Maestro
February 20, 2021

@GuitarSuperstar Is there a setting on your BR player to force a 5.1 output? Just out of curiosity, that fixed this exact issue in my experience. Do ARC/eARC sound bars use EDIDs or some kind of config file to tell TVs what their capabilities are? I wonder, is the problem that Sonos isn’t giving proper format instructions to upstream devices or that the sound bar isn’t properly mixing 7.1 down to 5.1. 

There isn’t a setting on my player to force 5.1.
 

If Sonos decides to fix the down mixing, that would be great, but honestly I am not too bothered by it because the rear surround speakers still sound great when watching a DTS movie. And if they fixed it, I’m not sure it would make much of a difference for most content.

"Receive with simplicity everything that happens to you." - Rashi
Lyricist III
February 21, 2021

I have an issue here with my pc and Sonos 5.1 system.    Lg cx connected to Sonos arc directly via earc. Dolby atmos videos work fine and even 5.1 Dolby tracks (though it says Dolby multichannel pcm 5.1, but whatever ).  
Now the problem I can’t solve, why I can’t play any games in PCM 5.1.  The Sonos app says it is playing pcm 5.1 or 7.1 but rears are not working properly. Rears only turn on when there is a sound in video game that turns on all speakers like an orchestra or certain game music. 
 

I have tried switching to auto or passthrough and still same problem. It seems like others have similar issues but anyone with video game issues like mine ?

Lyricist III
February 22, 2021

You have PCM sound issues while the Sonos app shows 5.1? That doesn’t track with any of the issues mentioned here that I saw. If the issues are with PCM 7.1 showing then yes, we all have had the same issue, check out the last few pages. You need to force your device (PC, assuming this is what you are gaming on?) to output in LPCM in 5.1. In my experience with PS, if you do that and the Sonos app says 5.1 PCM it should be good to go. There also seems to be another possibly unrelated issue with the LG CX. A few guys above are having issues with 5.1 signals showing as 7.1 (in app) that at least for me, do not exist (Sony TV). If you can’t force 5.1 on your PC, maybe just use DD. That is what I did with my PS4 before I swapped to PS5 and the option to override and force a configuration output showed up. 

Lyricist III
February 25, 2021

You have PCM sound issues while the Sonos app shows 5.1? That doesn’t track with any of the issues mentioned here that I saw. If the issues are with PCM 7.1 showing then yes, we all have had the same issue, check out the last few pages. You need to force your device (PC, assuming this is what you are gaming on?) to output in LPCM in 5.1. In my experience with PS, if you do that and the Sonos app says 5.1 PCM it should be good to go. There also seems to be another possibly unrelated issue with the LG CX. A few guys above are having issues with 5.1 signals showing as 7.1 (in app) that at least for me, do not exist (Sony TV). If you can’t force 5.1 on your PC, maybe just use DD. That is what I did with my PS4 before I swapped to PS5 and the option to override and force a configuration output showed up. 

OK so I did a recheck. Your right FishyD, I have the same PCM 7.1 issue and the channels are way off, and not accurate. I can not do DD on PC games, they are all in PCM, so I don’t know about forcing 5.1 LPCM (I don’t even know how to do it). In Windows, 5.1 and 7.1 are greyed out, only time sounds works is if i use “dolby atmos for home theatre” or Stero (showing as PCM 2.1). If I restart, for some reason i get option to do 5.1 or 7.1 select, but this produces no sound in my games and youtube. This is so frustrating….

Lyricist III
February 25, 2021

@Basid786 that is really frustrating. I was hoping that somehow you could force your PC to output 5.1 LPCM like I did on PS5. Or make your motherboard convert the game’s PCM to DD for an output (this worked on PS4). I haven’t played PC games in a while so I’m out of the loop on sound setups there. 
 

Perhaps some kind of software could take over Windows control of audio output? Check out this thread. It is somewhat related (forcing 5.1 PCM output over HDMI). https://www.reddit.com/r/htpc/comments/77ixil/can_i_force_windows_10_to_output_51_pcm_to_my/?utm_source=share&utm_medium=ios_app&utm_name=iossmf
 

The software is Equalizer APO. Never used it, no idea if it would work but there has to be a way on PC to do it somehow.