How do I know if my arc is outputting atmos? I have seen videos that show that if you go to "now playing" in the app it says that its outputting atmos. I have tried several sources (disney+, prime and netflix) that say they are dolby vision and atmos. When I play them the TV says its displaying dolby vision but nothing comes up regarding the audio and nothing is displayed in the app to say its atmos. I am using the LG 2020 GX and connected into the hdmi e-arc output. I have also used the hdmi supplied with the arc and also one I bought separately that is meant to support hdmi 2.1.
Is this an issue with the app (im using an android and i know that sonos don't support them as well as apple, but surly something as simple as if its playing atmos should work?) Any help or advice would be much appreciated.
Goto “settings/system/about my system” in the sonos app and check the codec in use next to ‘Audio In’ associated to the Arc in the device list.
Hi Ken, thanks for your reply.
Doing this, it says audio in is stereo 2.0, im so confused, I have no idea what I'm doing wrong or if the LG doesn't support the arc yet maybe?
Hi Ken, thanks for your reply.
Doing this, it says audio in is stereo 2.0, im so confused, I have no idea what I'm doing wrong or if the LG doesn't support the arc yet maybe?
I have the LG C9 and that is working fine with the Arc. Are you certain you are playing an Atmos Source?
Yeah 100% its advertised on disney+ as dolby vision and Atmos.
When I disconnect the hdmi and it switches to the internal lg speakers it then flashes up in the top right hand corner "dolby vision, Dolby atmos" then when I connect the hdmi back into the Arc, it flashes up with just "dolby vision"
Is this the TV’s own built in App from the LG App Store, or you using the Disney+ App from another device, like Apple TV?
Meanwhile here are some TV settings for you to check assuming they are same/similar to C9…
- ‘Settings/Sound/Sound Out’ - HDMI-ARC set to pass through (eARC is ON)
- ‘Settings/Sound/Additional Settings’ HDMI Input set to Bitstream & DTV Audio Setting set to Auto
- ‘Settings/Connection/HDMI Device Settings’ Simplink - ON / Auto Power Sync - ON
Just in case…
Note, if you are using Apps installed on Apple TV HD/4K, those devices (and some other peripherals) use the Multichannel LPCM codec which is not currently supported by the Sonos Arc and so you will need to switch the Audio out codec setting on those devices to use Dolby Atmos or Dolby Digital 5.1 to get surround sound, otherwise the audio may default to PCM stereo.
Sonos Staff have stated the LPCM codec will be supported at some point in the (hopefully not too-distant) future, so you may find it best to use the TV built-in Apps until that issue is resolved. The latest LG built-in Apps should all support DD+ Atmos.
Hey Ken, thanks so much. Going through the settings again and totally misses that e-arc was off. That was the only thing I had missed some how. Im now getting the "playing atmos" in the app. Thanks so much.
Glad to hear it’s sorted. Enjoy your new LG TV & Sonos Arc… and I definitely recommend using the Arc with Surrounds & the Sonos Sub too if you don’t have those already.
All the best.
Dont have them yet but have every intention of eventually adding them in.
Thanks again for all your help.
Take care 
Hi stephencollimore.
Welcome to the Sonos community and thanks for reaching out to us. I understand the situation you’re in and wanted to help.
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