Hi @Mike010101, Thank you for reaching out and welcome to the community. Thanks for alerting us about this issue. About this issue, so that we can check the status of the connections on the Sonos Arc to your TV and the output it is broadcasting, I’ll ask you to submit a diagnostic report to investigate further what could be causing this issue. You may reply to the thread with the confirmation number to assist you with this issue.  

Let us know what you have in mind with the advice above.

The Sonos community is always here to help.

Did you click additional settings under Sound on the LG? Then turn on eARC and set it to Pass Through. That will give you Atmos from various sources where it is available which you can tell by looking at the system info tab in the Sonos app. Click Treuplay to tune it and follow the on screen instructions to tune.

Thank you both.  I did find the two options to set ‘eArc’ and ‘Pass Through’.  They were at a different location than the setup videos i have seen.  So there i am good.

However, how do i know that i am outputting dolby atmos?  When i view a movie, show or youtube video, i don’t see any indication on the sonos App of whether sound is being streamed and processed as dolby atmos.

Thanks once more.

Hi @Mike010101, thanks for the update About your question, when you’re playing a movie or a Youtube video, It will show on the Sonos App on the now playing screen on what sound is being processed by the specific content that you’re watching. 

If you have other questions with your Sonos products, feel free to reach out.
The Sonos community is always here to help.

I did read that.  Where is the Now Playing screen?  Im not sure i see it or know what it is…

When i start the app, it goes to the My Sonos screen.  there i see at the bottom ‘Living Room Tv’. i click on it and  has a blank screen at the top, a moon and chat icon at the bottom and also a volume control.  But i see nothing else about the sound quality 

maybe im using the wrong app..not sure

If you want detailed info of what audio is playing click on the settings (cog wheel) in the app and then click on system > about my system.

Hi @Mike010101, thanks for the update. @ledzep1 thanks for assisting, and you’re correct. You may check that option on About my system to check on detailed information on what audio is playing. 

If you have other questions with your Sonos products, feel free to reach out.

The Sonos community is always here to help.

Ok, thanks...that is not very intuitive.  

Anyway, I got to where you suggested.  Now I go to amazon prime and searched for Dolby Atmos Movies and found quite a few.  But most of these on that screen: 

Dolby Multichannel PCM 2.0

Dolby Digital Plus

Dolby Digital Plus 5.1

But finally, I found one, only one! Jack Ryan:

Dolby Atmos (DD+)

Thanks much..u guess most movies aren't streaming with Dolby Atmos yet.

Hi @Mike010101, thanks for the update. About your question, it still depends on the content that you’re watching if Atmos is available or not. We can check and wait for feedback from other Sonos users about this concern if most of the content they are playing is mostly not showing Dolby Atmos. So they can share their experience as well. 

Let me know your thoughts with the advice above.

We're here to answer any further questions you have.