That’s ok @Corry P, I understand you guys are doing your best and appreciate your willingness to help. The issue is the LG OLED is one of the highest selling premium TV’s worldwide, and given the Sonos ARC is a premium sound bar designed for eARC TV’s, it is a big issue. LG Support have unfortunately over the years proven themselves to be beyond useless, so that’s likely why a lot of people are likely hoping Sonos can put pressure on them.

What happens is the LG TV has 2 main eARC modes that send multichannel audio. One is called “Auto” and the other “Passthrough”. It makes sense that a person would use passthrough on the TV to send through exactly what audio a device is sending the TV, through to the Sonos ARC. However this unfortunately results in any LPCM audio being sent as 7.1 regardless of whether it is LPCM 5.1 or 7.1. Other formats such as Dolby Digital and Atmos are unaffected and work properly, other than the Apple TV which seems to send everything other than Atmos as LPCM if it detects a TV or soundbar that supports LPCM.

The main problem with everything being sent as LPCM 7.1 is you end up with quiet audio and sound effects missing or coming from wrong speakers. I have no idea whether LG TV’s are just sending all LPCM audio in an LPCM 7.1 container and since Sonos doesn’t know what to do with LPCM 7.1, the issue is happening.

You can however change your LG to the “Auto” eARC mode I mentioned above which causes the TV to not send LPCM at all while still sending Dolby Digital and Atmos correctly. In this mode, all LPCM content is downconverted to Stereo which means the Sonos processes it properly. Since the Apple TV doesn’t see an LPCM compatible device, it sends audio via Dolby 5.1 and Atmos which comes out correctly. The main issue of course is that for gaming, devices like the Nintendo Switch don’t support Dolby and therefore you are stuck with Stereo. The PS4 and PS5 also have delays with Dolby Digital and many people prefer use LPCM as a result which will also just be in stereo using this mode.

I have chosen the latter “Auto” option personally as I would rather have stereo sound when something sends LPCM, than end up with audio coming out of the wrong channels. It however is an extremely annoying problem to have with high end equipment and one of the reasons I am returning my LG G1 for a Sony A90J as I’m not expecting the Sonos patch to fix it, the way a lot of other users seem to be.

Hi @billiejoe87 

Did any Sonos staff link to this thread in relation to the LG TV outputting 7.1 erroneously? If so, please let me know where.

This is a community forum and if community members, or indeed random visitors to the site, mistakenly link this thread as a complete explanation of a different issue, there’s not a lot we can do about it other than to start censoring posts (which we’re not going to do, and could only do here, not in other forums).

As 7.1 LPCM was mentioned here in relation to the Sonos Arc, and the Arc doesn’t currently support 7.1 LPCM, I reported exactly this here - I saw no need to dive any further into the issue. I did not mention LG TVs erroneously converting codecs, nor did I suggest that an update to Sonos would fix it. I simply said 7.1 LPCM is not supported on the Arc, but will be soon. At no point in the original post did the author indicate that the PS4 was outputting 5.1 LPCM while the TV was outputting 7.1. In fact, the author’s second post (first reply) brought up the “downmixing of 7.1 on Arc” subject, which is what I was replying directly to.

In addition, once the Arc does support 7.1 LCPM, I can’t see this being an issue any more - unless LG TVs are not converting to 7.1 properly (which is not something we can reliably determine before the Arc supports it). So, our update may well make the LG issue irrelevant for Arc owners, in which case waiting for the Arc update may actually be the best path forward.

Thank you Corry

Hi @billiejoe87 

I certainly can see where the confusion set in. Thanks for bringing it to my attention.

Yes - If I am ever referring to a reply rather than the initial thread, I’ll likely tag the person I’m replying to, and quote their post.

I did start my post with “Hi All” due to the recent activity, but my post was in reference to the initial post. Clearly, saying “Hi All” didn’t help clarify things.

Having said that, I also thought that I was responding to the LG bug posts as well, as our fix should make it irrelevant, as mentioned in my last post.

Hi @ledzep1 & @Shadylane 

At present, we have no time scale to share, I’m afraid.

Same problem with

Sonos Beam gen 2

LG G1

we get multichannel 7.1 instead of 5.1 in pass through mode

I’m really bummed to see that technology in 2021 continues to not play nice together. I appreciate sonos trying to solve this problem by offering downmixing but LG should be the ones to blame here imo. I just purchased the C1 and I absolutely love this TV and my arc setup but it’s disheartening seeing this issue. 
 

@Corry P is there any update to this with regard to the feature being worked on? I understand there might not a release window yet but it’d be nice to get confirmation that this is something that is still being worked on, considering more buyers will be picking up TVs like the C1 over the holidays. Thanks. 

I'm not sure intentionally cross posting on a forum is a very good idea.

So yeah for PS5 it’s showing PCM 5.1 ( not Dolby as I said in my previous post) but can also confirm that Apple TV 4K is still showing 7.1.

I’ve tested 5.1 output on PS5 for about 5 mins, no dropouts on Beam 2 / LG CX, latest software. 

can you make the PS4 output lpcm 5.? 

When I first started the ps5 it was set to “TV sound” lpcm 7.1 and while the number of channels can be changed it was greyed out. I changed the output type to “AV Receiver” and then it let me change the channel to 5.1. After doing that I confirmed in the Sonos app that the Arc was getting “Multichannel 5.1”. After doing this the sound output is correct.

Unfortunately i no longer have a PS4 to test but hopefully it has the same options.

Ive also got a PC and Nintendo Switch. The Switch asked me if I'd like 5.1 or 7.1 so I selected 5.1. The PC was a little tricky, on the PC I can output Lpcm or Atmos but it was defaulting to 7.1.2 or 7.1 for both - I found an option in Windows that let me disabled the SR and LR channel so now the PC outputs 5.1.2 or 5.1 only 

For those having issues with the LG CX outputting MultiChannel 7.1 to the Sonos ARC, have you tried changing the sound output to Auto instead of passthrough? This fixed the issue and changed it to Multichannel 5.1 for me.

It’s counterintuitive but leave the PS4 Pro/PS5 on PCM and change the HDMI Input on the TV to bitstream and the output to Auto. This fixed the issue for me.

Changing it to Auto changes the output to Dolby Multi-channel PCM 5.1, which is not the same as Multichannel PCM (LPCM)  as far as I know.

Ok that is nice, unfortunately not in my case. I’m using an Apple TV 4K and not a PS4 so perhaps there is a difference there. Have to do some more experimenting. 

Yes extremely weird. What is your source? I’m playing a blu-ray rip with DTS-HD 5.1 with Infuse. But I get the same with all Non-Atmos content from Netflix. I get Atmos with Netflix Atmos content. Below is what I get with audio output on Auto

Strange, I need to double check my settings but off the top of my head my LG OLED is set to passthrough and PS5 set to Output Type: AV Amplifier, Audio Type: LPCM, Channel setup: 5.1

I’ve seen you mention this, but no-one else (Myself included) has been able to do it. The Nintendo Switch only gives an option for TV Sound Output of Surround, Auto or Stereo. You cannot choose 5.1 or 7.1 on the Switch.

If you somehow know a way, please teach the rest of us.

LG CX and PS5 with Sonos Arc here. I’m using the settings below and getting some pretty solid sound with Dolby Multichannel PCM 5.1. So far any other setting results in Stereo PCM 2.0 and sounds worse. I know it’s not LPCM, but so far I can’t get anything else to work.

LG CX:

HDMI Input Audio Format: Bitstream

Digital Sound Out: Auto

PS5: 

Audio Format (Priority): Bitstream (Dolby)

HDMI Device Type: AV Ampoifier

Number of Channels: 5.1ch

Brilliant, this fixed along with the drop outs fixed will be all I want for Christmas

I have a different “issue” I’m not sure it’s an issue I never had the LPCM 7.1 but mine always reports 5.1 multichannel on the PS4 and when I turn a character around like in resident evil 2 remake and there’s water dropping it’s coming out from all channels, BUT on the settings on the TV the LG C9 I have the output to Bitstream, if I put to PCM I only get PCM 2.0 on the PS4….it’s weird if my TV is set to bitstream I can set everything to hdmi and PCM on the PS4 and get 5.1 audio I never got any option for 7.1, which is correct, but it changes it to 2.0 if I select PCM on the TV settings no matter if I set it to auto or passthrough I have the same thing

do you have any other games to test? With water the sound can sometimes come out all around you if that's what the developer intended, especially if the source of water is from a roof/fixture/waterfall that's above your characters head in the game. For example when it's a waterfall like in uncharted 4 you'll notice the sound everywhere if you stand close to the waterfall but if you stand far a enough away you only hear the sound based on your direction to the waterfall 

as for bitstream and pcm, use bitstream - as confusing as the names are, pcm is for 2.0 sound and bitstream is for higher quality surround audio 

I thought Multichannel PCM or LPCM was the better audio quality and that’s the new codec Sonos supports or maybe LPCM is different….as for the water it was coming specifically from a window and would only play on the channel I was facing that’s how I tested it, and yeah I tested it with horizon zero dawn and the last of us 2 to name a few

Still no LPCM improvement on my CX with the latest 03.21.09 fw gents

Isn't Sonos working on the fix?

A few posts above mentions this.

*I see you tweeted the CEO for an update.