Apple TV 4K, Sonos Arc and Dolby Atmos

Hi!

I did some digging around.

In the article "Play audio in Dolby Atmos or surround sound on your Apple TV" there is this smal text:

"*Some sound bars and AV receivers support Dolby Atmos, but don’t support video formats like HDR10 and Dolby Vision. In this case, you can plug your Apple TV 4K into either the sound bar or AV receiver to play sound in Dolby Atmos. Or you can plug your Apple TV 4K into your television to watch video in HDR and Dolby Vision. To do both, you need a television or an AV receiver or sound bar that supports both Dolby Atmos and high-quality video formats. Apple TV 4K uses a high bandwidth form of Dolby Atmos that doesn’t work over ARC connections."

So basically you need to plug in your Apple TV 4K in to your soundbar / AV receiver or use a connection that supports a higher bandwidth.

Now comes the bad part.

Because the Sonos Arc only have one HDMI port and, as you said, the only connection you can have is from Apple TV 4K to the TV and then from the TV to the Sonos Arc means your TV need to have eARC to be able to support the higher bandwidth and send it though to the Sonos Arc.

I understand that this isn't something you like to hear and I feel the same as I'm in the same situation with my Philips TV but I guess we can always leave a feedback for Apple.

The TLDR-version:

To use the Sonos Arc with your Apple TV 4K your TV need to have a eARC connection support.

I have a Sonos beam Apple TV and a projector. Sonos support told me that combination would not work. I bought a spitter. Apple TV goes in splitter. One out goes to projector and another out straight to the sound bar. Works perfect. I called today about the arc and the salesman told me it will not work without a tv. I’m going to try this anyway tomorrow and if it works I will update. If not I’ll return the arc. It has a 45 day satisfaction guarantee.

I have the new LG 75NANO90UNA tv which has an earth hdmi, I have that sending the signal to the Sonos Arc and I have the Apple TV connected to a regular hdmi but it refuses to play a sound when it goes into a movie that has atmos. When I go to the menu for the movie the theme music plays and when I play a non atmos movie the sound goes through but the minute I play an atmos movie from atyv it has no sound. I can play atmos from the Netflix app on the tv (Space Force) and it does show on the Sonos App that it is in Dolby Atmos. I am now at a complete loss as to what else to try as the entire reason I bought a brand new tv the Sonos Arc was to be able to play my atmos movies I bought that are on my Apple TV. If anyone has any ideas I would love to hear them, I have tried every setting I can think of, and the tv has arc set to on and passthrough enable also.

ARGHHHHHH

Hi!

Looking at the specs of your LG I see that it has eARC so you should be fine there.

Because you can play Atmos when using the Netflix app on your tv it sound like there is an issue with ether your Apple TV or the hdmi cable.

Is the hdmi cable connected between the Apple TV and your tv a high quality one that can handle a high bandwidth? (I personally have this one)

Are you using an Apple TV HD or 4K?

So this is the HDMI cable I’m using to connect the ATV: https://www.apple.com/shop/product/HLL52ZM/A/belkin-ultrahd-high-speed-4k-hdmi-cable-2m. Seems to be 48Gbps, although I would think that a 21Gbps cable should be more than enough for a DD+ signal. For connecting the Sonos I used the included HDMI cable.

However based on everything I’ve read so far, I’m starting to think it might just be my LG TV that is the champion here — for its ability to passthrough Atmos via Dolby Digital Plus. Of course it doesn’t support a lossless Dolby TrueHD signal (since it’s not eARC). But it looks like not all TVs with ARC actually support Atmos passthrough via DD+, even though they are able to process and play those signal on their internal speakers for instance. From my understanding LG have been quite good at supporting this for their TVs the last few years (my TV is a 2018 model).

Sorry to be the bearer of bad news, and I can’t say anything for certain as this stuff is obviously convoluted and complex, but it might just be a matter of what your TV is able to handle.

I’m having a hard time understanding this... Apple undeniably states that atmos isn’t supported over arc, and they even recommended your answer.

However I just got my Sonos Arc, and I’m using it with my LG C8 (it has ARC not eARC) and ATV 4K. I’m getting atmos signal (seeing The Dolby Atmos logo in the Sonos app + it states that atmos is playing in the system information portion of the app).

This is from both Netflix and for movies I have bought in iTunes that include Atmos sound.

I mean, I’m definitely not complaining! I just don’t completely understands the workings here and what’s really going on. As I see it there are 3 possible options:

1. The article from Apple is outdated and they now support Atmos over ARC.
2. The Sonos app is being tricked somehow into thinking that it's getting an Atmos signal, when it in fact isn’t.
3. The LG C8 is doing some sort of voodoo magic to make it all just work.

No idea if any of the these are true, or if something else is going on. But for now I’ll just enjoy the content I guess :)

it will not work. Check optical audio out specifications (TOSLINK Out):

Supported Audio formats & Specifications:

•  HDMI In: DTS-HD Master Audio, Dolby TrueHD, LPCM 7.1, DTS, Dolby-AC3 and 2.0CH 32KHz, 44.1KHz, 48KHz, 88.2KHz, 96KHz, 176.4KHz, 192KHz
• HDMI Out: DTS-HD Master Audio, Dolby TrueHD, LPCM 7.1, DTS, Dolby-AC3 and 2.0CH 32KHz, 44.1KHz, 48KHz, 88.2KHz, 96KHz, 176.4KHz, 192KHz
• TOSLINK Out : PCM and compressed audio formats up to 192 kHz (DTS, Dolby-AC3 and 2.0CH)
• Headphone Out : 2.0 CH stereo audio

JoarNord, it is essential in this community to post something that is true, and tried and tested. What you posted above is actually nonsense. I'd explains my setup.

1. Apple TV 4k --> Over high rest HDMI 4 K (48Gbps, HDMI 2.1 certified) cable connected to LF OLED C9, that supports Dolby Atmos, HDR10, Dolby Digital and also Dolby Digital. So from Apple TV to HDMI port 3 on this $1500+ new 2019 model TV.
2. TV has eARC enabled.
3. Sonos ARC (also on a 48Gbps, HDMI 2.1 certified) cable connected to the eARC port (HDMI port 2 of my TV).
4. On the TV, eARC is enabled, and sound passthrough is enabled.
5. On the Sonos ARC, audio compression is set to Auto (via the App).

The center channel is gone when you play Netflix in Dobly Atmos, or even Apple TV purchased / rented movies.

Only when the audio is changed from pass-through to auto on the TV ( step 4) above, you hear the audio, but Dolby Atmos logo is not displayed on the Sonos App. So it means it's down-ressing it to Dolby Digital.

Keeping the same settings on and playing the same movie from XBOX, I get tip quality Dolby Atmos, Dolby Digital and HDR no problem and even the Sonos App display the Dolby Atmos logo in the app.

My conclusion - Apple TV is buggy, a piece of plastic Cr**p , untested and falsely advertised. I spent over $1000 and hours fidgeting around to come to this conclusion. And no people, stop blaming a HDMI cable, since as I mentioned, on even a $30 cable, XBOX has no issues sending Dolby Atmos / Dobly digital signals

Updated to:

• Apple tvOS 13.4.8
• Sonos 12.0.3
• LG 03.10.25 (TV model still 65NANO91ANA)

no change, still no atmos with AppleTV 4K connected to Sonos Arc via eArc trying all the different possible passthrough settings.

@batsabode

Installed a new LG GX today and hooked up my Sonos arc and Apple TV 4K. I used all HDMI cords with 48gbps (not sure if it matters) that I got them from monoprice for around $20each.

After a few prompts on the ATV 4K prompting Dolby Vision, started up as normal. Streames Planet Earth, and the Dolby Atmos WORKS! Screenshot attached.

Same issue, here! ATV to HDMI 2 on Sony 65XBR900F, which is only a year old but no EARC support, Sonos ARC to HDMI3 (ARC) . Only Stereo and Dolby Digital 5.1 in audio output. Tried everything and no luck so far. Looking forward to helpful tips to resolve that.

Using ATYV 4K and just opened a new HDMI with Ethernet capable and it still does not work, EARC to Sonos Arc and the ATV plunged into HDMI 4 input which is one the two HDMI 2.1 ports (HDMI1= HDMI 2.0, HDMI 2 and 4 = HDMI 2.1, HDMI 3 = EARC (HDMI 2.0). It plays menu sounds and regular movies but when I play an atmos movie it will not work, there is zero sound. If I play an apple movie using the LG's Apple TV app then the same movie will play a sound but not be in the atmos format. So far Theo only thing I can get to play atmos is the Netflix app on the tv .

I’m having the exact same issue with my brand new setup LG 65 NANO85. No sound output at all on Atmos titles from Apple TV services (Netflix, Apple TV+ etc). TV HDMI setting is set to Bitstream, only other option is PCM. 

Any one know why I’m getting no sound at all from Atmos titles? This is so disappointing as I’ve purchased this whole brand new tv and setup just to get Atmos.

Apple TV sends it atmos signal out as MAT and until Sonos updates the arc to handle LPCM it won’t work we will just have to be satisfied with 5.1 unless Apple changes it’s output I have heard the xx arc in atmos using the Netflix or amazon prime app on the lg tv. Unfortunately lg does not support the appletv+ In atmos on the lg app at this time but have stated they will eventually. So at least we have some streaming services that work