LG C1 issue with eARC

Hi ​@Alex_D, welcome to the Sonos Community!

I’m sorry to hear that you’re having issues with your Sonos Arc dialogue becoming muffled while playing.

I don’t have an LG TV myself, but you have the TV settings set to what other community users recommend, so you likely don’t need to adjust anything unless the LG WebOS update changed something.

It’s odd that playing through optical will fix the issue on HDMI for a few days, this makes me think the HDMI cable either isn’t working or sitting correctly. Have you tried a different HDMI cable? If not, see if that helps instead of using the optical adapter.

There aren’t any steps I can see for muffled dialogue in our internal information; however, I do see steps to resolve muffled audio when Night Mode is enabled. Can you check whether you have this setting enabled on your Sonos system and if turning it off fixes your issue?

I hope this helps!

many thanks for follow up.

yes, I have checked few premium hdmi cables 2.1 as well as Sonos hdmi cable.

i agree, it’s very odd and not sure what causes the problem. 

I have LG as well just not your model. Had a problem with sound once. Called LG tech support. They walked me through resetting things as the process was a bit involved and not published for end user. Bottom-line try calling LG and explaining the before and after.

However, I would first run a diagnostic on the Sonos within 10 minutes of the next occurrence and record the reference ID. Do not publish the reference ID in the forum. Next call Sonos tech support so they can review the data. By doing so you can rule out Sonos. Worse case scenario it turns out to be a Sonos issue. Either way you’ll have answer before calling LG.

Try changing ‘pass through’ to ‘auto’

yup, i was changing pass through to auto with no result 

Please let us know what Sonos tech uncovers. However, in truth I’m doubtful. But one never knows for sure. Replacing the set may be the only solution provided it!’s not an LG CEC (SIMPLINK) implementation. If so the bug could be for your particular model or just an isolated production run.

starting painful replacement process. 2nd line support have not contacted for over 2 weeks. 

I do not understand why the replacement is so difficult since the ARC is few months old and on warranty.

i understand that things can stop working but how it’s being handled is way more important- and here - Sonos fails 

replay from 2nd level support.

this is why I bought whole system with ARC, SUB 3rd GEN and 2xEra 300…

I hope this email finds you well. First, I want to apologize for the delay in responding to your concerns. I understand how important it is for you to have a seamless audio experience with your Sonos speakers.

To prevent the issues you've been experiencing from recurring, it's essential to make some settings and configuration changes. Specifically, switching to the PCM format is the most effective solution. While I understand that PCM may not offer the same audio quality as Dolby Digital, it will ensure a more stable and consistent performance, which is crucial for resolving the current issues.

Here are the steps to switch to PCM format:

1. Open the Settings Menu: Navigate to the audio settings on your device.
2. Select Audio Format: Choose the PCM format from the list of available options.

I understand that you prefer to use your Era300 rear speakers with Dolby Digital for the best audio quality. However, switching to PCM will help prevent the recurring issues you've been facing.

Regarding your request for a replacement, I want to clarify that the issue is not due to a failure of your Sonos system but rather a format compatibility issue originating from your TV. Therefore, a replacement would not resolve the problem. This conclusion comes after an exhaustive review of the diagnostics and thorough investigation we conducted.

If you have any questions or need further assistance with this process, please do not hesitate to reach out.

I will leave it without comment