Channel mapping issue using Atmos (Apple TV / LG C1)

Hi ​@NP90 

Thanks for your post!

Sorry to hear of this issue you are having with the dialogue seemingly coming out of the wrong speakers, some of the time.

The fact that you only see this issue from time to time makes me think that everything is set up as it should be, and that the issue is either with the content itself, or this Infuse Pro software you mention.

Do you see the same issue if you play the same content through a different app? If not, I’d look into the app being the source of the problem. Although I admittedly am not overly familiar with macOS, I have never heard mention of this Infuse Pro software before and wonder if that might be the source of the issue.

We do not hear reports of channels playing out of the wrong speakers very often, but I believe the last time I heard of it, an LG TV was involved. Have you experimented with different Digital Audio Output Format (exact wording will probably vary) options on the TV? It might be worth changing it to Auto or Passthrough.

To be honest with you, I really don’t think this is a Sonos issue - you mention that most content works as it should, and we do not re-map channels in such a fashion. I do wish you luck in finding the source of the issue, however.

If more info comes to light, please add it here - it may well shed a light on some aspect of the issue.

It might be worth turning everything involved off and on again - power-down the Apple TV, unplug the TV and Arc from power for a full minute.

I hope this helps.

Hi Corry, thanks for the response.

Infuse Pro is an app on the Apple TV for handling media libraries. It passes through lossy Atmos content where something like Plex does not. (So the Sonos app shows ‘Dolby Atmos’, instead of Multichannel 5.1)

If I play through Plex, or disable ‘Atmos’ on Infuse, it plays as Multichannel 5.1 and is fine.

But when ‘Atmos’ is enabled, I get dialogue out of the rear speakers and almost nothing out of the Arc itself.

I’ve tried a complete power cycle of everything and still having the issue I’m afraid. I have also sent a sample of the file to the Infuse developers, so they can analyse at their end.

The reason I raised this here was because I have an LG OLED TV and there was a similar thread I found: 

“Specifically, when channels are playing from the wrong speakers - for example, but not limited to, if you hear dialogue only coming from the rear speakers, consistently.”

Hi ​@NP90 

Thanks for the description of Infuse Pro!

If your content is E-AC3 (Dolby Digital + (w/ Atmos)), then Plex should not be playing it as Multichannel 5.1 - it should pass the DD+ through to the Arc so that the Arc can play it as Atmos - you may want to look into the Plex player app’s settings for that. Perhaps the Apple TV’s output settings too (though, do not select the Arc as the output device as that will use AirPlay - keep it set to the TV).

The thread you linked to is rather old (3 years) and never really amounted to much - we were getting vague reports and wanted to clarify if people were definitely getting mapping errors - if I recall correctly, it did not amount to much in the end (at least for us to address), though there were definitely some mapping issues reported with LG.

Please ensure you have the following settings on your TV:

I hope the Infuse Pro dev team find something that explains this.

Again, I’d encourage you to test with other content on other apps - if you have no issues with playing Atmos on Netflix or Amazon Video, for example, then the issue likely lies with the content or software used.

I hope this helps.