AppleTV Dolby Atmos and LG TV Passthrough

Apple recommends Apple TV → audio equipment → TV, as Apple’s Atmos output is a high bandwidth form that may not be supported by other equipment in between.

Additionally, Settings﹥Apps﹥iTunes Movies and TV Shows﹥Quick Start must be On.

Play audio in Dolby Atmos or surround sound on your Apple TV - Apple Support

Apple TV 4K uses a high bandwidth form of Dolby Atmos that doesn’t work over ARC connections.

Snelfie wrote:

Also, do the AppleTV+ inbuilt app stream Dolby Atmos?

“Support for Dolby Atmos will be coming later this year [for the Apple TV app]," LG has said.

Folks, the issue here is with the Sonos Arc. It cannot handle LPCM signals (Apple TV apparently sends Atmos information via Dolby MAT, not Dolby Digital Plus). That's why Atmos doesn't work with iTunes movies, but it does with the built-in TV apps that send Atmos metadata via DD+.

Sonos has promised a firmware update for the Arc; you can google this. Apparently a lot of people (including myself), are in this situation, so I'm guessing it'll be sooner rather than later.

Snelfie, what Urquhart1244 is recommending is not applicable here. He assumes that the TV you are using uses ARC, your TV has eARC and is very capable of recieving and processing Dolby Atmos.

I believe the issue is with the LG Nanocell line. Whether I use the Sonos Arc or the TV's internal speakers, I cannot get any sound to play for any content that has Atmos-based sound coming from the AppleTV. I have an LG 65" OLED TV that does not have this issue with the same HDMI cable and the same AppleTV. The OLED TV only has an ARC (some ARC implementations support Atmos, Sonos lists the ones they've tested their Arc with) but is able to send Atmos audio via the ARC to my Sonos ARC as well as play the Atmos Audio through the OLED's internal speakers.

I submitted a Customer Service request with LG and I recommend everyone else who has this problem to do the same to inspire LG to fix the issue.

There may be an issue with the Sonos Arc (I've seen the posts on the Sonos forums about it), but it's not the culprit here. Like some of the other posters, including myself mentioned, the issues occurs even if we remove the Sonos Arc from the system. No Dolby Atmos sound coming from the 4k AppleTV plays using the LG Nanocell's internal speakers or the Sonos Arc. However, if I use the AppleTV App (or other WebOS apps that support Atmos sound) I get Dolby Atmos sound through the internal speakers and through the Sonos Arc (after reconnecting it).

I have an LG 65" OLED and get Atmos through my Arc and Internal Speakers from the AppleTV no problem. Because of that, I'm leaning towards this being an issue with LG's Nanocell line.

It’s a combination of factors. I have an LG OLED C9 that works without issues with Sonos Arc and Apple TV 4K. However, it’s because I didn’t install the LG LPCM update. With the update the LG tries to passthrough MAT which Sonos Arc can’t do OR tries to send LPCM, which the Sonos Arc also can’t do. If you installed the update (or TV came with it), the built in TV apps will work without issues, but you’ll have to wait for the Sonos Arc LPCM update for it to work properly with Apple TV 4K (or for LG to tweak their settings with how the Auto setting works on the TV). There is also a temporary workaround for Apple TV 4K where you have to manually change setting for when you’re watching something with Atmos vs non-Atmos audio.

I just installed the 86” lg90 Nano 2020 model and Sonos ARC installed today. Spent hours trying to figure out this exact problem. No sound on the pass through from my appletv 4K for atmos output...however, Netflix, appletv, Disney+ apps on the TV apps all send atmos to the ARC. Would love to understand root cause of this and get it fixed in a future update from either LG or Apple or both.

Correct. My 86” Nanocell was returned today due to this issue. Went with the Sony X950H. So far so good.

Hope that helps someone.

It's been mentioned in this thread already what the problem is.

Native Dolby Atmos requires an eARC capable device. Other service providers will used a Dolby Digital Plus stream encoded with compressed Dolby Vision in order to bypass the eARC requirement.

I have the same issue on the same tv. 2020 LG 86” Nanocell Series 9. Spent the last few hours trying to get the right settings to make Atmos sound play on my Sonos ARC or the LG’s internal speakers from the AppleTV. Neither do.

An interesting observation: I can get the Arc to play Atmos content from the AppleTV on my 2017 LG 65” OLED using ARC (not eARC like I have enabled on my nanocell). This isn’t an eARC vs ARC issue as others in this thread have stated. This is an issue between the AppleTV and the LG nanocell. The sound issue exists whether I use my Arc or attempt to play the Atmos content through the bult in speakers. However, I can play Atmos sound content sourced from outside of the AppleTV.

It’s a real bummer. I came to terms with the lower quality image as a trade off for size, but fully expected with eARC I’d have higher quality audio. Downgrade on both fronts. I’d recommend holding off on the Nanocells till LG and/or Apple get this resolved.

P.S. What's nice here until Sonos ships the firmware is that LG's Apple TV app is the first one to support Dolby Atmos and that works great. (I have the LG OLED55BXPUA)

Selfie.... I am looking to get the same TV for use with my Sonos ARC.... Can I ask are you getting a Atmos signal from any of the LG TV Apps (Disney+, Netflix, Prime)...... Look like LG might fix the Apple TV app later in the year...

Any help appreciated... thanks in advance.

Hello,

How exactly is your Apple TV set up?

Example:

Apple TV <-> HDMI <-> TV <-> Optical Audio <-> Sound Receiver

I have the same setup but the 86” model. I cannot get atoms from appletv. It just comes out with nothing. Stumped 🤔 I do get atoms from native tv apps