Arc/Atmos - TV support for passthrough from Apple 4k?

 

 

Hi there, what FW is your LG running?

(also, why no Chroma 4:2:2?)

I’ve got the most up to date FW on TV (checked this out about 3 times) also had confirmation from LG that my TV is capable of LPCM passthrough. 
 

I get DD 5.1 passthrough from AppleTV when Audio Format is set to Auto with Atmos off. As soon as I enable Atmos on AppleTV it show Atmos Available but I get no sound at all. 
 

LG TV set up with eARC on and HDMI Input as Bitstream and Passthrough enabled. 
 

(Tried all different video settings in Apple TV and still no change to what happens with audio)

 

Odd that we’re seeing a mix of behaviour.

 

Like you, I get DD5.1 when ATV is on auto.

I also get Atmos working perfectly when that’s enabled on ATV.

However, with Atmos enabled on ATV any DD5.1 content is output via multi channel LPCM. since the latest LG update it now passes this straight through to the ARC. The ARC cannot process this yet, so I just get a left and right channel.

 

So, at the moment I have to toggle the audio setting on the ATV based on what I am about to watch!

 

It’s very odd as Apple TV and ARC seem to do different things for different people. 

Are you using the HDMI cable that came with the Sonos Arc? I wonder if upgrading to an HDMI 2.1 cable Will make a difference?

The issue with Apple TV content outputting as Stereo appears to be due to the newest LG C9 firmware for LPCM. I’d advise not upgrading to 04.80.03 if your main media device is the Apple TV until Sonos patch in LPCM for the Arc.

 

 

Hi there, what FW is your LG running?

(also, why no Chroma 4:2:2?)

I’ve got the most up to date FW on TV (checked this out about 3 times) also had confirmation from LG that my TV is capable of LPCM passthrough. 
 

I get DD 5.1 passthrough from AppleTV when Audio Format is set to Auto with Atmos off. As soon as I enable Atmos on AppleTV it show Atmos Available but I get no sound at all. 
 

LG TV set up with eARC on and HDMI Input as Bitstream and Passthrough enabled. 
 

(Tried all different video settings in Apple TV and still no change to what happens with audio)

 

Odd that we’re seeing a mix of behaviour.

 

Like you, I get DD5.1 when ATV is on auto.

I also get Atmos working perfectly when that’s enabled on ATV.

However, with Atmos enabled on ATV any DD5.1 content is output via multi channel LPCM. since the latest LG update it now passes this straight through to the ARC. The ARC cannot process this yet, so I just get a left and right channel.

 

So, at the moment I have to toggle the audio setting on the ATV based on what I am about to watch!

 

It’s very odd as Apple TV and ARC seem to do different things for different people. 

Are you using the HDMI cable that came with the Sonos Arc? I wonder if upgrading to an HDMI 2.1 cable Will make a difference?

Using Sonos cable at the moment. Can try a full 48gbps 2.1 cable as I have some spares. I don't believe that will help in my case.

Most people probably have auto update (me included)

I do have a copy of the previous firmware though, so may see if the TV will flash this via the USB port.

Very odd.

Same TV OS, same input device, same settings, should = same result.

CX runs WebOs 5 and I am currently on the .60 release although others are reporting that they are running .70.

I have auto update turned off.

The cable to the Arc is the one that came in the box.

The cable from the ATV is nothing special (amazon basics range)

Grasping at straws a little, but have you tried connecting the ATV to a different HDMI port on the TV?

Another TV setting that may have an impact on things is the DTV Audio setting, mine is set to Auto.

Last setting to check on ATV

I have the LG 65SK9000PUA with ARC connection and I get Dolby Atmos fine (Disney+ & Apple+)  except with Netflix (ATV4K). I’ve only tried it with the movie Underground 6. I have the Arc with two Sonos Ones behind the couch. It seems the audio gets confused in to where it should be coming from and will crackle and drop out from the rear Sonos Ones and sometimes the main dialogue will come through the rear speaker. My setup is ATV4K>LG>ARC. Atmos comes through perfect from the LG apps (Netflix & Disney+). I’m not using the HDMI cable that came with the ARC, not long enough to run through the wall to connect both. Thinking of trying the cable that came with it to see if there’s a difference. 

Anyone using an LG B9/C9 and Apple TV 4K are going to be extremely dissappointed.  As of the latest firmware update released just days ago you have the choice of Dolby Digital 5.1 support or Atmos and 2.0 audio for everything else.

Reason behind this is LG updated their LPCM passthrough to support Multichannel.  Apple TV sees this and chooses to passthrough LPCM instead of Dolby Digital 5.1 causing Sonos to downmix to 2.0.  Atmos will still play properly.  Only solution currently is to disable Atmos and set the Apple TV to change ouput to Dolby 5.1 while watching non Atmos content.

What poor timing.  I got to enjoy my Arc for 1 full day.

Just went through the ringer of talking to everyone Sonos, Samsung and Apple. In typical fashion Sonos blamed Samsung and Apple. If your TV does not have eARC I don’t think there is a way currently to get Dolby Atmos out of your ARC. If Sonos ARC supported a passthrough we would be fine but unfortunately there is only one HDMI connection. Best audio output I can get is DD 5.1

Apple TV 4k-Samsung 7 series-Sonos ARC