I can confirm the bad news.

HDMI ARC and apple tv 4 k . the apple tv does not recognize sonos arc aa an atmos device. Hence you will get only dd 5.1.

as mentioned before paying so much for a soundbar that is limited to hdmi ARC that the majority of 2019 and before tvs do not support passthrough atmos codec… makes it useless and futile… will return the bar shortly and recommend all the buyers to makensure either their tv support atmos passthrough or dont even think of buying Arc.

i have nu8000 tv apple

tv 4k setting needs to be bitstream imput and output will be automatically chosen to you DF 5.1 if you chose PCM you will get 2.0 stereo.

to confirm what audio signal you are getting go to sonos app settings about sustem and you will seee under arc the input signal coming from the tv… goodluck and goodbye sonos!

as

Not from anything playing from AppleTV 4K. I only see Dolby Atmos when playing certain content in the LG TV Netflix app.

copied all the settings for both AppleTV and LG TV and all I get I’d Dolby 5.1

 

 

Hi there, what FW is your LG running?

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

 

 

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)

 

 

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!

 

 

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

Really??? My new LG 75NANO90UNA has EARC which I have connected to the Sonos Arc, I have tried all settings on the tv ate arc and ATV, currently passthru on lg tv and ATV set to Dolby Atmos, and so far I have not been able to get the arc to play any sound when the movie is Atmos, it plays the theme music when on the menu for the movie but as soon as I hit play there is not sound at all. So I totally feel that the arc. cannot process the Atmos signal being send thru the LG tv by ATV (MAT) to it. When I use Netflix on the tv app and play an atmos show (Space Force) it works perfectly, but does not for the LG appletv+ app which apparently does not support atmos at the moment but LG states it will, hopefully on their next update. This is totally frustrating to not have Sonos accept the signal from so many set top boxes like ATV. ! The only thing that gives me hope is that Sonos has stated they will update Arc to accept  LPCM, again hopefully soon. As an aside the Sonos app shows the dolby 

I’m glad that i found this thread as I thought I was the only one having this issue. I have a nano90 and the Apple TV 4K. I also have all brand new 2.1 HDMI cables and whenever anything with atmos tries to play i get no sound at all. If it doesnt have atmos then it plays fine. I currently have atmos just turned off on the Apple TV. Are we sure though that once the ARC supports LPCM then we will have atmos support? My tv also supports atmos on the internal speakers and I tried playing things from the Apple TV with atmos and again got no audio. Meanwhile i played a blu ray and got atmos on the internal speakers. Has any one else tried this?

Really sad to see how Sonos dint really learn from it’s experience with the Playbar and later the Beam. 
 

I haven’t bought a an Arc myself so of course cannot ad anything in terms of possible remedying this issue but I do recognize the years of frustration from working with all of previous Sonos soundbars. 
 

Best advice when buying Sonos for home theater is to plug them in, lean back and enjoy whatever comes out of the speaker. Just hope that whatever setup you have will give you the best the speaker has to offer but don’t ever check the Sonos app for confirmation - that will likely lead to frustration and a long road of frustration end expenses to maybe get things working the way they should. 
 

As always: if you care about what codec you are getting, Sonos really isn’t for you unless you buy a third-party receiver with support for Works with Sonos. 

Seems a very mixed bag of results at the moment, hopefully the arc update isn’t far off, can only imagine those with a lesser interest in the forums etc purchasing an arc and thinking it’s faulty.
 

Like many I have a C9 which has updated to the the latest FW, I do get Atmos from ATV4K on supported movies, but, anything outside that and any app run from ATV that requires 5.1 does not output any dialogue, so it’s ATV for movies & C9 internal apps for anything else.

How are you getting atmos from the arc thru your tv to the arc I guess your lg has a different software that works better with arc to get the signal to the arc any insight would be gelpful

Hi. What TV have you got? The LG C9 has earc and supports ATMOS pass through, so movies I’m playing off the Apple TV will pass ATMOS to the Sonos, but, due to the recent LG firmware update to support LPCM, it’s stuffed the delivery of any content like DD5.1 from the ATV to include vocals as the Sonos can’t process it. 
 

I’ve not made any changes just had to use ATV for only Atmos movies & TV apps for everything else (Netflix etc on the tv will also play Atmos if it’s included so it’s all a mixed bag really.

HDR

Model:75NANO90UNA which has EARC on one of the hdmi. I have the Sonos Arc connected to that and the ATV to one of the. other HDMI 2.1 inputs. Mine must have something in the lg that stops it sending the signal to the arc as if I try an Atmos movie from ATV there is not sound unless I go to the top menu for the movie with extras then. it plays the theme music but again once I start the movie and look at the Sonos app it states silence, at least they got that right it is silent lol. I know it works with the Netflix and amazon prime on my tv and when I look at the Sonos app on iPhone. it has Dolby Atmos as the input. 

Again I guess my tv has a different piece of software than yours that works.

Hi, Hmmm...sounds odd then as logically with earc all should be fine regardless of software. I’m sure you have but as another check ensure:

TV, Go to Settings > Sound > Sound Out. There should be some settings for HDMI ARC. Check it is set for ‘Digital Sound Out’ as ‘Pass Through’.

Yup I just rechecked everything and the HDMI earc is on, the out is passthrough, Atmos is enabled on ATV and the hdmi input for the hdmi that the ATV is connected to is bitstream (I also tried it on PCM ). All results the same no sound when actually playing the movie in Atmos but sound when. its not an atmos movie. I looked at. the app on my phone and it had 2.0 for the input. When everything else is played is states 5.1

Weirdly I just updated the Sonos apps on. my iPhone and MacBook just before this conversation so I really thought perhaps that. update would be support of LPCM

Hi everyone.  I also bought the new LG 75NANO90UNA and Atmos does not work through Apple TV with Sonos Arc. I tried everything and then decided to check the forums..thought I had a bad TV.   Whew., I normally don’t use the apps that come with the tv but I read that Netflix app on LG TV supports ATMOS if you have the Ultra HD plan….I set it up and it works with the ARC.   So I am just going to disconnect the Apple TV 4K until Apple and Sonos fix this.   I have been an Apple and Sonos user for a long time and it is really getting old when they say it supports „this“ and it doesn’t.  Anyway I hope they correct soon.