External Sound bar for LG 2018 C8 OLED

avMAC

Novice Member
Hello, need help where to go next. Purchased a Samsung Q950A sound bar, but my 2018 LG TV (OLED55C8PUA) states in a message that ATMOS is for Internal speakers only. So it turns off ATMOS when I send sound through the HDMI ARC cable to my sound bar with internal App or not. Do I need a TV that has eARC?

I purchased a new Roku Ultra since it has ATMOS, but not getting the ATMOS through it, actually not sure yet, but still wanted to get some advice. Please Help, thanks MAC
 

next010

Distinguished Member
From what I can remember the C8 supports DD+ Atmos over ARC so it should in theory work with the Samsung Q950A.

You must configure the digital sound output = auto on the LG for it pass Dolby from internal apps and HDMI sources, HDMI devices may need additional configuration to output DD Atmos.

If it still wont work the Samsung bar has HDMI inputs if you connect the Roku to those it should play Atmos that way.
 

avMAC

Novice Member
Thanks "Next", will try the HDMI to the Roku idea. Not sure how to make that work since there is only one input on the Roku and it needs to go to the TV for the signal. Strange that the LG TV doesn't want to cooperate. I think the newer models passthrough, but when you check the ATMOS it's grayed out. Thanks again for the reply.
 

avMAC

Novice Member
Update:
Found that if you go on Youtube you will find plenty of videos to test your system. After listening to some it looks like the Roku ATMOS is working. The LG TV internal apps put out very good sound and are louder, but still not sure if you are getting ATMOS signal. The "ATMOS ON" buttons are always grayed out and no ATMOS message comes up on screen. Keeping the Q950A sound bar for now, LG in 2021 are came out with eARC so maybe those TV's will pass ATMOS through.
 

next010

Distinguished Member
Thanks "Next", will try the HDMI to the Roku idea. Not sure how to make that work since there is only one input on the Roku and it needs to go to the TV for the signal. Strange that the LG TV doesn't want to cooperate. I think the newer models passthrough, but when you check the ATMOS it's grayed out. Thanks again for the reply.

Connect the Roku to the HDMI1 input on the Samsung, connect the Samsung HDMI to TV (ARC) output to the HDMI2 ARC port on the TV.

For ARC usage (passing audio from TV to Samsung) the input should be ARC/TV on the soundbar, this is usually automatic.

For using the Roku switch to HDMI2 input on the TV then use the Samsung remote to cycle to the soundbars HDMI input.

Also you might have to configure the Roku Settings/Audio/HDMI="Auto passthrough"

Update:
Found that if you go on Youtube you will find plenty of videos to test your system. After listening to some it looks like the Roku ATMOS is working. The LG TV internal apps put out very good sound and are louder, but still not sure if you are getting ATMOS signal. The "ATMOS ON" buttons are always grayed out and no ATMOS message comes up on screen. Keeping the Q950A sound bar for now, LG in 2021 are came out with eARC so maybe those TV's will pass ATMOS through.

Youtube does not output surround sound, its stereo only, some YT clients fake surround output.

According to the manual Dolby Atmos should appear in the mini display of the soundbar upon activation. You might want to test with the Roku directly connected to the Samsung on something you know outputs Atmos or get something else to test Atmos with.
 

avMAC

Novice Member
Thank you, the details this time really helped me navigate through this connection issue, also for the Youtube correction. I shouldn't be handing out advice that's not been verified. I have to say YT does a great job of faking it.

The connections you recommended worked great and you have to be standing over the Samsung to see the 10 second display state it's getting Dolby atmos, but was great to get that verification. The sound level I was using on the bar dropped to "12" (Was using "20" for the same sound level ). Tried through the TV apps and no atmos displayed on the sound bar. So using the Roku did help, I guess for older TV's you will need the latest Roku Ultra.

For a reference, if you have HBO the movie "Godzilla vs. Kong" states in the intro description "Dolby atmos - Dolby vision - 4k UHD". Haven't seen that before, was picking "4k UHD" movies and assuming they were broadcast with atmos. Will have to go back and check.

Thanks again for the suggestions, was a big help.
 

avMAC

Novice Member
Just wanted to add that Netflix Originals has a lot of atmos titles. States it in the description. I believe you have to subscribe to their Premium service for it to work. I did, and it works. It's only $3 more.
 

dkh1972

Novice Member
I'm curious why the soundbar won't passthrough 4K/HDR10+ while also pumping Atmos directly to the soundbar.
 

dkh1972

Novice Member
Tried through the TV apps and no atmos displayed on the sound bar. So using the Roku did help, I guess for older TV's you will need the latest Roku Ultra.
You won't get Atmos from any of the C8's built in apps because it cannot be passed over ARC, only eARC.
 

sagaris99

Well-known Member
While technically correct, OP isn't going to get the higher-quality Dolby TrueHD and DTS-HD Master Audio streams from the improved bandwidth provided by an eARC connection.
'higher quality'

The difference would be imperceptible using a Q95A, even if any of the apps on the LG actually supported high res audio anyway, which none of them do.

You don't need 'higher quality' streams to experience Atmos. DD+ provides a more than suitable Atmos soundtrack to be played over ARC to a soundbar.

So, to say
You won't get Atmos from any of the C8's built in apps because it cannot be passed over ARC, only eARC.
Is just incorrect. Especially when OP wasn't actually asking about eARC and lossy vs lossless.
 

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