Is LPCM = Dolby Multi-Channel PCM?

No. Dolby has nothing to do with PCM.

Dolby Multi-Channel PCM is the label used for a Dolby MAT container signal that contains PCM and metadata vs. a Dolby MAT container that contains TrueHD.

This is what I see on my Sonos app when I play a DD 5.1 content.. 

 

pretty confusing not knowing if my Sonos Arc is producing the right sound or it has a bug interpreting the Source audio Content as it doesn’t match what it says on the source title vs on Sonos system info

 

 

The Arc is likely not confusing the input. It’s more likely that the source content is DD 5.1 but the source device is deciding to decode it and wrap it in a MAT container before passing it onto the next link in the HDMI chain for consistency reasons.

 

: If you see my testing results on Sonos Beam, Beam is receiving Dolby Digital 5.1 content from the TV ( Netflix App on Samsung Q70T  → TV HDMI eARC → Sonos Beam’s ARC HDMI connection - Sonos Beam ) with the same settings. The only difference here is the Sonos Arc ( Netflix App on Samsung Q70T  → TV HDMI eARC → Sonos Arc eARC HDMI connection - Sonos Arc ) which is receiving Dolby Multi-Channel PCM 5.1

Right, each device has different audio format capabilities in part due to the bandwidth available over ARC vs. eARC. These capabilities are communicated to the TV in a couple of ways.

MAT is only available over eARC so only the Arc advertises this to the source. It is ultimately up to the source device what format it transmits. In your case it decided to prefer MAT over DD since it is available on Arc.

Is LPCM = Dolby Multi-Channel PCM?

No. Dolby has nothing to do with PCM.

Dolby Multi-Channel PCM is the label used for a Dolby MAT container signal that contains PCM and metadata vs. a Dolby MAT container that contains TrueHD.

This is what I see on my Sonos app when I play a DD 5.1 content.. 

 

pretty confusing not knowing if my Sonos Arc is producing the right sound or it has a bug interpreting the Source audio Content as it doesn’t match what it says on the source title vs on Sonos system info

 

 

The Arc is likely not confusing the input. It’s more likely that the source content is DD 5.1 but the source device is deciding to decode it and wrap it in a MAT container before passing it onto the next link in the HDMI chain for consistency reasons.

 

: If you see my testing results on Sonos Beam, Beam is receiving Dolby Digital 5.1 content from the TV ( Netflix App on Samsung Q70T  → TV HDMI eARC → Sonos Beam’s ARC HDMI connection - Sonos Beam ) with the same settings. The only difference here is the Sonos Arc ( Netflix App on Samsung Q70T  → TV HDMI eARC → Sonos Arc eARC HDMI connection - Sonos Arc ) which is receiving Dolby Multi-Channel PCM 5.1

Right, each device has different audio format capabilities in part due to the bandwidth available over ARC vs. eARC. These capabilities are communicated to the TV in a couple of ways.

MAT is only available over eARC so only the Arc advertises this to the source. It is ultimately up to the source device what format it transmits. In your case it decided to prefer MAT over DD since it is available on Arc.

Can’t agree more with your explanation. Thank you!

So in an ideal cases what is the best format that the TV should be transmit to Sonos Arc over eARC for a DD 5.1 content? I some how feel that the DD 5.1 that is outputting from Xbox / Apple TV 4K ( using pass-through )  and transmitting to Sonos Arc sounds better than Dolby Multi-Channel PCM 5.1 via native app on the TV. 

Is LPCM = Dolby Multi-Channel PCM?

No. Dolby has nothing to do with PCM.

Dolby Multi-Channel PCM is the label used for a Dolby MAT container signal that contains PCM and metadata vs. a Dolby MAT container that contains TrueHD.

This is what I see on my Sonos app when I play a DD 5.1 content.. 

 

pretty confusing not knowing if my Sonos Arc is producing the right sound or it has a bug interpreting the Source audio Content as it doesn’t match what it says on the source title vs on Sonos system info

 

 

The Arc is likely not confusing the input. It’s more likely that the source content is DD 5.1 but the source device is deciding to decode it and wrap it in a MAT container before passing it onto the next link in the HDMI chain for consistency reasons.

 

: If you see my testing results on Sonos Beam, Beam is receiving Dolby Digital 5.1 content from the TV ( Netflix App on Samsung Q70T  → TV HDMI eARC → Sonos Beam’s ARC HDMI connection - Sonos Beam ) with the same settings. The only difference here is the Sonos Arc ( Netflix App on Samsung Q70T  → TV HDMI eARC → Sonos Arc eARC HDMI connection - Sonos Arc ) which is receiving Dolby Multi-Channel PCM 5.1

Right, each device has different audio format capabilities in part due to the bandwidth available over ARC vs. eARC. These capabilities are communicated to the TV in a couple of ways.

MAT is only available over eARC so only the Arc advertises this to the source. It is ultimately up to the source device what format it transmits. In your case it decided to prefer MAT over DD since it is available on Arc.

 

Can’t agree more with your explanation. Thank you!

So in an ideal cases what is the best format that the TV should be transmit to Sonos Arc over eARC for a DD 5.1 content? I some how feel that the DD 5.1 that is outputting from Xbox / Apple TV 4K ( using pass-through )  and transmitting to Sonos Arc sounds better than Dolby Multi-Channel PCM 5.1 via native app on the TV. 

I would leave your settings as they are if you are getting the higher bandwidth formats (MAT or TrueHD). I can’t explain why DD would sound better with the same content unfortunately.

This really needs sorted. Having to use stereo is a joke for an 800 quid product 

Agreed. Hopefully it gets sorted before my return period ends. 

Any update on this?

I was pretty shocked to find out that I can’t get surround sound for Switch out of my new Sonos Arc. I appreciate that Nintendo is too cheap to ever license DD5.1 so I really hope Sonos will do a fw update asap with support for multichannel PCM.

On my C9 (stupid firmware update got me) on my Apple TV, i went to to settings > audio (I think it’s audio) and flip the audio from Auto to 5.1 it’s a temp work around to get audio out of the ARC. Otherwise, it comes through all kinds of messed up and you can’t hear anything.

With that said, i’m just as mad as everyone else and hope they get this LCPM update out ASAP.  Kinda disheartening to buy into a product thinking you’ll get Atmos sound only to have to revert back to 5.1.. Especially after spending over 1k on getting the whole setup.

I know they’re trying to fix the issue with an update but I would of rather them push the release back a bit and shipped with the firmware update… I feel like I’m beta testing a half baked product and it leaves a bad taste in my mouth. 

lol if anyone over in Sonos land is looking at this I will happily volunteer to use a beta firmware to fix this cause well, what do I have to lose at this point?

I have the same setup and Atmos works fine. The problem occurs when you have the Apple TV set to “Auto, Atmos” and play 5.1 content. The firmware update enabled LPCM for the LG C9. Apple TV set to “Auto, Atmos” will then deliver sound as LPCM as it now recognizes the C9’s support for it and considers it the next best thing to Atmos, i.e. rates it above DD5.1. 

The workaround, like you mention, is to set the Apple TV to “Dolby Digital 5.1” for 5.1 content. You will then need to switch back to “Auto, Atmos” for Atmos content.

For WebOS built-in apps there are no problems. Plays Atmos (when available) and Dolby Digital Plus for 5.1 content.

Thanks for helping me explain it. I had a feeling I didn’t explain that 100% correctly but yeah, we are in the same boat. 

Is there an update on this? It’s a simple update and having to use stereo on stadia/ switch due to the £800 ARC not being able to do LPCM is disappointing and I’m looking to return the bar for another that can do all formats out the box. I appreciate its being looked at and there is no eta, but this should have been a feature out the box 

Thanks to everyone for the feedback so far. Support for multi-channel LPCM is in active development. We'll be testing over the next few months to be part of a future software update. We will update the community once it's available.

Thanks for the update. Sound like it won’t be done in time before return periods end... 

That’s why I initiated my return. It appears Sonos will roll out LPCM support alongside other features in a larger update. Sonos should just release the LPCM update on its own as soon as it’s ready. It shouldn’t take long as it’s a simple code and would keep customers happy. I appreciate it makes more sense to release one larger update from a workload point of view, but a lot of customers are dependent on LPCM support and I currently have to use the ARC as a Glorified stereo speaker and there are better and cheaper options for this

A few months?

I just got an LG BX and have my Arc plugged into the eARC port - yet when I play any Dolby Atmos content via my Apple TV 4K I get no sound (tried heaps of combinations of settings to no avail).

From what I understand this is due to the arcs lack of LPCM support. So my Arc will be a very large brick until this update is released in a few months?

You could perhaps ‘switch’ audio codec in the Apple TV settings to Dolby Digital 5.1. I believe that should keep things going with surround sound until the multichannel LPCM update arrives. 

Okay I’ll give that a go, thanks mate! At least I’ll get some kind of output for now :)

You should be able to receive Atmos from the apps within the TV itself if you want to receive the full sound until the codec is updated.  Not ideal, but better than having to wait for the update to be completed.

Hi Scott! I assume this also applies to the Beam?

No point for the beam. Can’t pass 5.1 LPCM over HDMI ARC or optical anyways

what if scott has a beam connected to a TV with EARC? 

The Beam doesn’t support eARC though. So still no dice

I see 12.0.3 is out today. Is this issue addressed in this release? 

Just replying to the thread so I can see updates as I’m waiting for the LPCM compatibility too. 

Still No LPCM support with latest update. I don't expect it for good few months going by Sonos update history 

Hey gang,

 I’m also in the Apple TV 4k / Arc LPCM boat. Just wanted to leave a post to remind me to check in as soon as possible when this is resolved. Hopefully it’s soon because the Arc is great otherwise if they could just get this working.