LG has released a firmware upgrade for the B9/C9/E9 supporting multichannel PCM passthrough. This is great except Arc doesn’t support it yet.
Because of this new update, my Apple TV decides it should use LPCM instead of Dolby Digital 5.1 with Atmos enabled resulting in only 2.0 audio for non Atmos content. The current only workaround is to disable Atmos and enable it when you want to watch an Atmos file. Very frustrating as the previous firmware had no issue.
In the same boat here, just got Arc and I'm very disappointed with the whole Apple TV debacle… would really appreciate the LPCM support soon, otherwise I’m gonna have to return the soundbar, it’s simply not worth the hoops
You should return it then. Sonos isn’t going to give an update on LPCM before they have the software. And LG probably isn’t going to fix their firmware (but maybe!). Honestly the easiest fix is one from LG, so I’d start posting over there to get them to do something.
In the same boat here, just got Arc and I'm very disappointed with the whole Apple TV debacle… would really appreciate the LPCM support soon, otherwise I’m gonna have to return the soundbar, it’s simply not worth the hoops
You should return it then. Sonos isn’t going to give an update on LPCM before they have the software. And LG probably isn’t going to fix their firmware (but maybe!). Honestly the easiest fix is one from LG, so I’d start posting over there to get them to do something.
How come LG is on fault here they just start supporting passthrough of LPCM over earc. Its sonos arc which doesn’t support LPCM.
In the same boat here, just got Arc and I'm very disappointed with the whole Apple TV debacle… would really appreciate the LPCM support soon, otherwise I’m gonna have to return the soundbar, it’s simply not worth the hoops
You should return it then. Sonos isn’t going to give an update on LPCM before they have the software. And LG probably isn’t going to fix their firmware (but maybe!). Honestly the easiest fix is one from LG, so I’d start posting over there to get them to do something.
How come LG is on fault here they just start supporting passthrough of LPCM over earc. Its sonos arc which doesn’t support LPCM.
I guess argument could be made that LG should enable users to turn the support for new feature on/off, if it can affect other devices down the chain? But yeah, that’s not gonna happen, and Sonos Arc launched with promise of support LPCM down the line, so...
In the same boat here, just got Arc and I'm very disappointed with the whole Apple TV debacle… would really appreciate the LPCM support soon, otherwise I’m gonna have to return the soundbar, it’s simply not worth the hoops
You should return it then. Sonos isn’t going to give an update on LPCM before they have the software. And LG probably isn’t going to fix their firmware (but maybe!). Honestly the easiest fix is one from LG, so I’d start posting over there to get them to do something.
How come LG is on fault here they just start supporting passthrough of LPCM over earc. Its sonos arc which doesn’t support LPCM.
When you use eARC to transmit an audio signal, you are really relying on the TV for processing (or the device manufacturer you are streaming from - here Apple). When you selected “Auto” previously, the LG was processing the signal from LPCM to bitstream tor the Arc. Now it is not doing that anymore, which puts the onus on either Apple to process down to bitstream (which it won’t) or Sonos to support LPCM.
What you’d really want is for LG to fix this, because it would be a fix for any product - even if you switch out of Sonos to something else. Whether other products are impacted right now, I don’t know (I haven’t used other soundbars), but you’d prefer to have the TV doing the processing as needed. That’s what an “Auto“ mode should be accomplishing. Right now, it’s really just passing through a signal the Sonos cannot support. Because it didn’t do that before, it suggests LG broke the capability with its last firmware update. It’s also why this isn’t an issue with other TV manufacturers - their TVs are doing this processing.
I’m not sure if that’s the case: from what I understand the LG TV’s weren’t supporting multichannel PCM before, so they were always provided signal that was compatible in different way, like DD5.1 etc.
now they support it, so Apple TV and the like send it through, and TV can play it just fine on speaker or feed through to eARC… assuming that the device on there can understand it… and Sonos Arc can’t.
I’m not sure if that’s the case: from what I understand the LG TV’s weren’t supporting multichannel PCM before, so they were always provided signal that was compatible in different way, like DD5.1 etc.
now they support it, so Apple TV and the like send it through, and TV can play it just fine on speaker or feed through to eARC… assuming that the device on there can understand it… and Sonos Arc can’t.
It is the case. They weren’t supporting it - they were processing it to bitstream. You can see posts about folks with LG TVs who did not upgrade their firmware and don’t have the issue.
I’m not sure if that’s the case: from what I understand the LG TV’s weren’t supporting multichannel PCM before, so they were always provided signal that was compatible in different way, like DD5.1 etc.
now they support it, so Apple TV and the like send it through, and TV can play it just fine on speaker or feed through to eARC… assuming that the device on there can understand it… and Sonos Arc can’t.
It is the case. They weren’t supporting it - they were processing it to bitstream. You can see posts about folks with LG TVs who did not upgrade their firmware and don’t have the issue.
Wouldn’t that suggest that there’s a bug in LG firmware? That should pass on bitstream if connected to Arc instead of sending LPCM? I’ve done some googling since I got the Arc, and that doesn’t seem to be the conclusion. So I don’t know.
either way: as mentioned in couple of Arc reviews as well and this forum, Sonos did promise to bring LPCM to Arc. So I just hope it’s gonna happen sooner lather than later. 
I’m not sure if that’s the case: from what I understand the LG TV’s weren’t supporting multichannel PCM before, so they were always provided signal that was compatible in different way, like DD5.1 etc.
now they support it, so Apple TV and the like send it through, and TV can play it just fine on speaker or feed through to eARC… assuming that the device on there can understand it… and Sonos Arc can’t.
It is the case. They weren’t supporting it - they were processing it to bitstream. You can see posts about folks with LG TVs who did not upgrade their firmware and don’t have the issue.
Wouldn’t that suggest that there’s a bug in LG firmware? That should pass on bitstream if connected to Arc instead of sending LPCM? I’ve done some googling since I got the Arc, and that doesn’t seem to be the conclusion. So I don’t know.
either way: as mentioned in couple of Arc reviews as well and this forum, Sonos did promise to bring LPCM to Arc. So I just hope it’s gonna happen sooner lather than later.
That’s exactly what I’m saying. There is a bug/feature removal in LG’s latest firmware.
Hi, again ewolkoff. Thanks again for your tremendous help.
That worked - in that by changing the setting Sound > Additional Settings > HDMI Input Audio Format > Bitstream, I was then able to set the Apple TV to Atmos.
Can you explain how that is possible? That changing settings on one device impacts the options on another (ie, changes to a device downstream affects the primary device (4KATV, LGTV, ARC)?
However, despite Atmos being available from the Apple TV, as soon as I play any Atmos content from it (either via the iTunes Store or Disney, etc) there is no sound coming through the soundbar.
Back to square one. :(
TV is still set to Auto and not Pass Through? Also are you sure it’s Atmos content? I have noticed that with this setup DD 5.1 plays sometimes with no sound or no voices until I switch to Pass Through again. That’s why the system is manual — you have to change the settings to play DD 5.1 vs. Atmos.
The issue before was that you told your TV to only accept a stereo PCM signal. Apple TV saw that and stopped allowing you to send high bandwidth Atmos signals.
Hi there, CX owner here,
I have looked at you settings on previous pages, so is it a case of I can get atmos but if a movie or show on the apple tv 4k box is in 5.1 I need to manually change a setting on the apple box.
On my LG I have everything set to passthrough, eARC on e.g.
What setting is it on the apple tv that I would manually need to change to get atmos and then 5.1 until sonos release the LPCM update.
Thanks
Any update on this or if we can beta test this?
SoCal - I don’t think that’s correct.
As for the rest of this thread, I can report that I am running the latest firmware on an LG E9 and do not have this issue. My Apple TV is playing Atmos without having to do anything in the audio settings. Just make sure your audio setting is set to “Auto” rather than “Pass Through” or PCM.
But what about when you’re trying to play DD5.1 content? On my system (Apple TV, LG C9, Sonos Arc, it plays Atmos content perfectly but the Sonos Arc sees DD5.1 content as Stereo 2.0.
So I connected my apple tv 4k up yesterday to my LG CX (eARC)
I can get atmos and DD 5.1 fine, without changing any settings on the apple tv 4k box, so why are some only getting stereo 2.0 with 5.1 content?
I admit I only tested using Apple iTunes content that I had purchased, but I don’t plan on using any other apps on this device so its fine for me it seems.
My Lg is set to passthrough with eARC on.
Does the issue lie with certain apps on the device or something, as the guy I quoted has a C9 so why does he have an issue and I don’t.
Hi
Welcome, thank you for reaching back to Sonos Community.
I'll submit a feature request to add LPCM to a supported audio format to our development team.
We don't have a timeline we can share for this feature, but we'll be sure to make an announcement if we have any updates.
In the meantime, you can check this link for the Supported audio formats in Sonos.
If you need help with any other information, please be sure to let us know.
Hi
Welcome, thank you for reaching back to Sonos Community.
I'll submit a feature request to add LPCM to a supported audio format to our development team.
We don't have a timeline we can share for this feature, but we'll be sure to make an announcement if we have any updates.
In the meantime, you can check this link for the Supported audio formats in Sonos.
If you need help with any other information, please be sure to let us know.
Hi
I’m confused, do you Sonos support staff talk to each other at all?
I thought LPCM was already in the works to be added sometime in the near future, confirmed by some sonos support staff on here already.
I mean with all the issues with the ARC currently it sounds very worrying when a support staff member responds as if he has no clue about LPCM already being confirmed as getting added eventually.
“I'll submit a feature request to add LPCM” - reads to me this didn’t exist yet, is that the case? Because this was already promised months ago on this forum by Sonos staff.
Hi
Welcome, thank you for reaching back to Sonos Community.
I'll submit a feature request to add LPCM to a supported audio format to our development team.
We don't have a timeline we can share for this feature, but we'll be sure to make an announcement if we have any updates.
In the meantime, you can check this link for the Supported audio formats in Sonos.
If you need help with any other information, please be sure to let us know.
Hi
I’m confused, do you Sonos support staff talk to each other at all?
I thought LPCM was already in the works to be added sometime in the near future, confirmed by some sonos support staff on here already.
I mean with all the issues with the ARC currently it sounds very worrying when a support staff member responds as if he has no clue about LPCM already being confirmed as getting added eventually.
What on Earth has happened with Sonos support? You used to have Ryan and others here actually reading questions and following up. Now you get the support that looks like it’s come straight from the Philippines on behalf of some **** **** manufacturer.
LPCM support was promised months ago, we need an actual follow up here, as the wait is getting ridiculous.
Now this is interesting - with Arcana and TVOS14, audio set to Auto - Atmos enabled, the ATV BITSTREAMS DD5.1 over eARC to my Sonos Arc. And it sends the full Dolby MAT stream, which is the point of the Arcana of course. So for me, this LPCM requirement is off the table but I can imaging it’s still needed for those TVs where this doesn’t work. Not sure though if TVOS14 has changed anything on this front.
Now this is interesting - with Arcana and TVOS14, audio set to Auto - Atmos enabled, the ATV BITSTREAMS DD5.1 over eARC to my Sonos Arc. And it sends the full Dolby MAT stream, which is the point of the Arcana of course. So for me, this LPCM requirement is off the table but I can imaging it’s still needed for those TVs where this doesn’t work. Not sure though if TVOS14 has changed anything on this front.
What’s Arcana?
Ah ok thanks. Yeah presumably that box doesn’t support LPCM which is why Apple TV doesn’t send such signal to it.
It does support LPCM as it is full eARC. I guess it properly reports the Sonos limitations over EDID to the ATV which my Panasonic OLED doesn’t do properly (neither does LG).
Highly recommend the Arcana for Sonos Arc users!
My LG BX updated it’s firmware last night and as of today is passing Dolby Atmos through to my Sonos Arc (from an Apple TV 4K). Even says “Dolby Atmos” in my Sonos App!
So maybe LG adjusted their firmware to pass through something the Arc is compatible with while Sonos get their own firmware sorted?
My LG BX updated it’s firmware last night and as of today is passing Dolby Atmos through to my Sonos Arc (from an Apple TV 4K). Even says “Dolby Atmos” in my Sonos App!
So maybe LG adjusted their firmware to pass through something the Arc is compatible with while Sonos get their own firmware sorted?
I have been able to pass atmos from my apple tv 4k to ARC since the CX was released back in April.
Was it certain apps on the apple box that prevented this?
My LG BX updated it’s firmware last night and as of today is passing Dolby Atmos through to my Sonos Arc (from an Apple TV 4K). Even says “Dolby Atmos” in my Sonos App!
So maybe LG adjusted their firmware to pass through something the Arc is compatible with while Sonos get their own firmware sorted?
I have been able to pass atmos from my apple tv 4k to ARC since the CX was released back in April.
Was it certain apps on the apple box that prevented this?
There was an issue where LG updated their firmware to accept LPCM, so the Apple TV 4K would send that (which the Arc isn’t compatible with) and you’d get no sound unless you forced ATV to output at 5.1
Not sure why your CX wouldn’t have that issue unless you didn’t update firmware or something?
My LG BX updated it’s firmware last night and as of today is passing Dolby Atmos through to my Sonos Arc (from an Apple TV 4K). Even says “Dolby Atmos” in my Sonos App!
So maybe LG adjusted their firmware to pass through something the Arc is compatible with while Sonos get their own firmware sorted?
I have been able to pass atmos from my apple tv 4k to ARC since the CX was released back in April.
Was it certain apps on the apple box that prevented this?
There was an issue where LG updated their firmware to accept LPCM, so the Apple TV 4K would send that (which the Arc isn’t compatible with) and you’d get no sound unless you forced ATV to output at 5.1
Not sure why your CX wouldn’t have that issue unless you didn’t update firmware or something?
I have kept CX fully up to date.
I only really use my apple tv 4k for the apple content such as purchased movies but have never had an issue playing Atmos or DD 5.1 content.
My settings on CX are are set to passthrough with eARC on, and on the Apple box just the defaults Auto/atmos on.
On sonos App, it showed ATMOS DD+ or Dolby Digital 5.1
Strange.
I believe a new firmware is out in the UK, but currently Im on 3.10.44
My LG BX updated it’s firmware last night and as of today is passing Dolby Atmos through to my Sonos Arc (from an Apple TV 4K). Even says “Dolby Atmos” in my Sonos App!
So maybe LG adjusted their firmware to pass through something the Arc is compatible with while Sonos get their own firmware sorted?
I have been able to pass atmos from my apple tv 4k to ARC since the CX was released back in April.
Was it certain apps on the apple box that prevented this?
There was an issue where LG updated their firmware to accept LPCM, so the Apple TV 4K would send that (which the Arc isn’t compatible with) and you’d get no sound unless you forced ATV to output at 5.1
Not sure why your CX wouldn’t have that issue unless you didn’t update firmware or something?
I have kept CX fully up to date.
I only really use my apple tv 4k for the apple content such as purchased movies but have never had an issue playing Atmos or DD 5.1 content.
My settings on CX are are set to passthrough with eARC on, and on the Apple box just the defaults Auto/atmos on.
On sonos App, it showed ATMOS DD+ or Dolby Digital 5.1
Strange.
I believe a new firmware is out in the UK, but currently Im on 3.10.44
Odd. It’s a confirmed issue by Sonos that they need to add LPCM support, you must have just been lucky somehow!
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