LG OLED C9 Series_eARC Support

  • 17 June 2020
  • 4 replies

Userlevel 7


Since the launch of the Sonos Arc; which now brings Dolby Atmos to Sonos Home Theater, the burning question has been whether or not one’s current TV will be compatible to pass the Dolby Atmos signal. The short answer is “yes” if the TV manufacturer claims that Dolby Atmos can be enjoyed over HDMI-ARC to a compatible speaker. Emphasis on “TV manufacturer claims”.:thinking:

The fine print of that statement is that the signal is compressed over HDMI-ARC. In order to enjoy lossless Dolby Atmos (uncompressed signal) the TV must support eARC over HDMI.

As an FYI...the LG OLED C9 Series does support eARC. However, the HDMI port on the C9 series is only labeled as ARC which at first glance suggests eARC is not supported.

Ah...but wait...LG decided to make eARC selectable (on/off) in the menu settings. Here’s how to activate eARC for the LG OLED C9 Series:

Settings > All Settings > Sound

  1. Set Dolby Atmos to On
  2. AI to Off
  3. Sound Mode to Standard

Sound Out

  2. Digital Sound Out set to Auto or PassThrough
  3. eARC set to On

In case you’re wondering (as was I) why LG made eARC selectable rather than an active port click this link for an explanation. Although given by a 3rd party I believe it’s as good as any available.  

I hope someone finds this information useful. Enjoy.


This topic has been closed for further comments. You can use the search bar to find a similar topic, or create a new one by clicking Create Topic at the top of the page.

4 replies

Userlevel 1
Badge +1

If you are trying to pass TrueHD Atmos, make sure that Digital Sound Out is set to Passthrough.  I was seeing TrueHD Atmos being converted to Dolby Digital Plus Atmos when set to Auto.


I’m not sure if your first set of steps is necessary.  I think those only apply to the internal speakers of the TV.  I’m pretty sure that those get grayed out when HDMI-ARC or eARC are active.

Userlevel 1
Badge +1

Another thing to note.  The TV always reports that DTS is supported, even when using the Arc.

You need to have a way to disable DTS in your source device, or you could end up in a situation where you don’t get sound.

Userlevel 7


The purpose of the post was inform those that may own  a LG C9 series that eARC is supported. The trick is to know how to enable it.

In your first post you are correct about the grayed out items. Steps aside I want to make sure no was confused by Atmos showing as “off”.  Although  the settings apply to interval speakers one should have set Atmos to “on” for a proper setup.  Otherwise why buy the LG when a 4K  set costing less might due for picture quality alone.

To your second post on DTS I wasn’t going to muddy waters discussing it as the post related to eARC for Dolby Atmos. IMO the subject of DTS has been discussed and exhausted to infinity. 


i have the issue of having to re-select Passthrough everytime i switch to Netflix from watching tv.

if not my pair of surround Play 1s won't have any sound.

do you have this problem?

i tried finding solutions on the web bit no results.