900H owner here. Apple TV is on HDMI 2, Xbox on HDMI 4 (in VRR mode for the HDMI port so no DV). 

Arc pops with both. 

So I was very curious this weekend.  I was thinking  perhaps Xbox had fixed the issue and that my disabling Dolby vision and auto HDR wasn’t necessary, as I had been symptom free for over a month

So I deactivated both and within two days of light play I got the pop, and it was with a game that uses both natively (Forza Horizon 5).  There is definitely something behind this line of thinking that Dolby Vision is causing some of the issue

I have since deactivated both again and have been symptom free again

Stay Tuned

Thanks for sharing the data point. I get the pop on Xbox even with DV turned off. For EDID reasons, I always have DV off on my Xbox. I also don’t use auto HDR.

It wouldn’t surprise me — I’ve been saying for a good while now that the culprit is specifically the Dolby MAT container, and it’s usage with Atmos.  Definitely smells like there is a potential bandwidth issue, somewhere.

I only get the issue when returning to the Home Screen, never during gameplay.  I’m going to put my money on it being some HDMI handshake issue when returning from Dolby Atmos / Vision back to standard SDR

Does anybody know if Atmos leverages the Dolby MAT container when the two are used in parallel?  Or if the sound operates outside of it?

Also worth noting that if I mute the Sonos hardware itself before the potential of a pop, the pop still occurs, however if I mute the Xbox by turning on headphones, it never occurs.  More evidence that it’s a device issue opposed to a Sonos issue

I believe the issue is that the Sonos hardware detects a change in signal from Atmos to Silence, and fails to compensate, but the reason behind why the signal drops appears to be occurring upstream. (You can see this in the “About my System” information screen).

The MAT container is used for handling audio in an uncompressed LPCM format with Atmos metadata sprinkled no top, which the Apple TV uses (with no option to change otherwise, just “off”)—it makes little difference to Vision.  As it’s uncompressed, the bandwidth required will be, certainly, higher.

As a test, I stuck my Apple TV in 4K60 HDR rather than Vision, but left match source on. Played 3 Vision and Atmos across Netflix/Disney+ without issue.

That said, I believe the Apple TV also gives me issues with the XH92 (X900H in the UK) that I use in that I cannot load the “Live TV” apps built into the TV when swapping from HDMI 2 to the app. The TV just locks up.  When you finally get it to reboot, the Apple TV drops it’s DV (again, now changed to HDR) signal to SDR until you flick inputs and back again.

I believe the problem lies with the Apple TV, and maybe the notorious Bravia — and that between the two, some signal is plain and simply, getting f’ed.

Hi @TheFlamesFan 

Thank you. We appreciate that, but at this point I don’t think a video will be of any help - nor will diagnostics, unusually. We’re seeking to be connected to an Arc in devmode and recording while one of these events happen (see it as telemetry for a race car) so we can analyse the incoming feed. This will involve having an engineer on the phone with you at the time (most probably), so it’s a difficult task if an event can’t be triggered within a few minutes.

It’s a shame we don’t have a HDMI splitter-type device that can pass through the audio from an Apple TV to the Arc, and video to a TV.  Isolate the TV as not being part of the issue…

I have followed your instructions and reached out to support. At first support told me the problem was specific to my TV and to turn off eARC. After some talking, I managed to convince him that I am supposed to reach out. I’m posting here just to make sure it really gets to you.

I can get a high confidence pop within 30 minutes. If I could have an hour of devmode, I would be willing to sit there and see how many pops/timestamps I can generate for you without an engineer on the phone.

What are the specifics of your setup? Which TV model are you using, and was it the native app within the TV or an external device, if so, which?

The TV was a Samsung 65QN90B and it was a native app on the TV

Thanks — could you humour me, if you play some Atmos content in the same way, and open the Sonos App and navigate to Settings > System > About my System, what do you get for “Audio In”? Atmos (DD+), Atmos (TrueHD), or just “Atmos”.  I’m guessing it’s the latter?

Yes it just says Dolby Atmos

So another device pushing out the MAT container.  Interestingly, this is a direct TV to Sonos Arc connection via the native app, so the TV isn’t acting as the passthrough middle man or anything.  That would also, potentially, remove some theories about bandwidth being an issue, as surely, only the audio would be routed to the Arc?

@Dirtynes — if your TV has the option to change the audio output format from Linear PCM to Dolby Digital Plus or TrueHD, that should alleviate the issue for yourself.

I have done that already. Just a shame I cannot use the Atmos function until they fix the cause of the issue.

Curious..what tv do you have and I take it you have nothing else hooked up to your system? 

I also tried an experiment, I set my HDMI 3 (eARC/ARC) to Enhanced format (Dolby Vision). And when playing DV DA content on my Apple TV with my Apple TV Video format setting to 4K HDR 60, disabling Dolby Vision on my Apple TV. The popping error occurred like clockwork. 
 

Then I changed the HDMI signal format on my HDMI 3 to Enhanced Format without Dolby Vision. With my Apple TV format setting to 4K HDR 60, disabling Dolby Vision on my Apple TV. The popping error did NOT occur, and the Sonos Arc was able to play Dolby Atmos as long as the Dolby Vision was disabled in both my Sony TV HDMI setting and my Apple TV.

This is somewhat confusing — so you attempted to use the “Enhanced (Dolby Vision)” HDMI profile for your Arc, which is connected to HDMI 3 (for eARC reasons), despite that setting being an Input profile i.e. the Arc doesn’t output DV, or even 4K for that matter.  Confused as to what difference this would make, unless the Arc is getting heavily confused at the EDID settings  

Also assuming that whilst your Apple TV was set to 4K60 HDR, you also had “Match Dynamic Range” turned off in settings?

Interesting about the screensaver thing — I’ve been wondering about this myself for a while.  I’ve been curious if it’s been something to do with the source change triggered on the screensaver activation  

I would be interested if the Apple TV is changing dynamic range during this time.  Maybe you mentioned it before but what are your video settings?  4K sdr or Dolby vision?

Previously, I was using 4K60 DV with both content match options enabled. I'm now on 4K60 HDR with both options still enabled. Currently rocking without Atmos for a whileC see if I still experience static pops and similar when flicking between content sources (like Netflix’s auto-playing trailers).

I did try it for a day, and got through three movies as above without fail, but then, it might've just been a good day. You're welcome to mirror and let me know your experience. 

My Apple TV is on 4K SDR 4:4:4 with dynamic range and frame rate matching, and I haven’t had issues.  Sounds to me it’s only a issue when systems are trying to force DV as was the case with my Series X

I have a Sony 900H and replicated some of this testing today. For those unfamiliar with the TV, it has 4 possible settings for HDMI ports 3 and 4: Standard (HDMI 2.0), Enhanced (HDMI 2.1, No DV, No VRR), Enhanced (with DV, no VRR), Enhanced (with VRR, no DV). HDMI 3 is the eARC port, so where the Sonos Arc is plugged into.

With the Apple TV set to HDR (not DV) and confirmed in the TV overlay, there was no pop with HDMI 3 set to either Enhanced or Enhanced with DV. In other words, the HDMI setting made no difference.

I know some are drawing a conclusion that turning DV off means no pop. This has only been shown on Apple TV. Both Xbox (observed by me) and Samsung TV internal apps (observed by another poster in this thread) will produce the pop even when DV is turned off.

In my testing I encountered something else. Sonos products put out a video signal on the HDMI port that I would describe as a screen saver. I had never looked at the one of the Arc before, but I noticed that the video had glitches. The normally black-and-white picture included color pixels randomly strewn throughout. Does this have anything to do with our problem? I don’t know. But I ask you all to tell me the following:

1. Does your Sonos Arc have “glitches” in its screen saver video signal?
2. Have you had the pop?

Just maybe these glitches are only showing for those with the pop, which could be a sign of something.

Match Dynamic Range is On. As I’ve stated multiple times for those still saying Dolby Vision off makes No Difference. This ONLY applies to APPLE TV. NOT Xbox Series X or Samsung TV which I also had, before I purchased Sony. I also have a Sony X900H. The Xbox Series X is what caused this popping error specifically for the Sonos Arc. 

Those still claiming this is not a Sonos issue. Again for 4th time. I had ZERO issues playing DV and DA content on my Sonos Arc for over a year on an LG and a Sony, (2 TV’s in different rooms). Until I plugged in an Xbox Series X and the popping error occurred, after which the Sonos Arc immediately began to exhibit the popping error on any DV DA content from any source.

The Sonos Arc NOW has a PERMANENT (until there is a fix, even though it’s been 2 years, with zero fix) error playing DV DA content from any source. Prior to the Xbox Series X initially causing the popping error. My Sonos Arc had ZERO issues playing DV DA issues.

And the reason I tried this experiment is because people still claim that turning the DV off on their APPLE TV NOT XBOX. Doesn’t solve the issue. The HDMI 3 eARC was incorrectly set to Dolby Vision when I purchased my Sony X900H. I never adjusted it, until I had this popping error.

Again to reiterate for the 6th TIME. The Dolby Vision being disabled or turned off on both my Sony TV and Apple TV NOT XBOX DOES SOLVE the popping issue. I watched Blade Runner 2049 which is 2 hrs 43 min long. ZERO ISSUES playing Dolby Atmos on my Sonos.

Then I watched Live Die Repeat: Edge of Tomorrow. Both are Dolby Vision and Dolby Atmos content.

As soon as I did my experiment, setting the HDMI 3 to Enhanced Format (Dolby Vision). The popping error occurred despite my Apple TV NOT Xbox DV being disabled. Meaning that the signal being sent from the TV to the Sonos Arc, still causes the error on the Sonos Arc. Making it a Sonos Issue.

I have given up on trying to play the Xbox Series X on my Sonos Arc.

Exactly!