Sonos has just a single escalation engineer in the ANZ region from what I have been told. He has gathered several diagnostics and we even tried changing the Arc as a whole but didn’t help. Upon asking, he said we have a lot of detail from your system and do recognise the problem but don’t have a fix in place. Now, I have had this much earlier than yourself ( 4 weeks now ) , so given the fact there may be others like myself or people who don’t use the community but have provided the diagnostics, I would reckon Sonos has the data they need but can’t determine where the problem is. There is a lot of money spent in buying the entire system and surely they need to stand up to it. Honestly, I have a JBL go worth 50$ and has never caused problems whatsoever. Sitting with data for weeks isn’t going to help anyone either.

Just an FYI for Apple TV users. The best way to avoid sound loss seems to be to change the Apple TV audio out setting from ‘auto’ to ‘Dolby 5.1’. This means all audio output is transcoded to Dolby 5.1 and this seems to stabilize the audio output with Sonos speakers connected via HDMI ARC/eARC. Speculatively, there seems to be something going on whereby audio codec changes seem to be causing issues. This can manifest by changing sources i.e from Cable Box to Apple TV etc. or even within Youtube (in my case) where different videos are encoded with various codecs etc.

Clearly they haven’t figured it out given the issue is still seems to persist after today’s firmware update. I just don’t wish to go into subjectives/comparitives based on intent/value as I find it unproductive.

16.4.2 most likely wasn’t released to address this issue. with a loose understanding of software development this release was probably already in the testing stages before this thread was even created assuming they do their due diligence and take the time to properly test

I’m starting to think that the update broke something in our systems and it can’t be solved. I’m so disappointed and frustrated. I no longer have warranty and no one would buy it from me at this condition.

I sincerely doubt that is the case

You still think they have testing stages prior to a release? I highly doubt this

I also doubt this is the case.

The most likely scenario is that there is functionality in 14.6 (and higher internal builds) that is required to enable product launches that are either out now (new Sonos Roam colours) or coming very shortly (rumoured min-sub, headphones, etc).

As a result, Sonos can’t simply issue a new firmware that is functionally a ‘rollback’ of 14.6 without removing code that other teams in the company absolutely NEED to be live and in production right now.

I’m sure they’ll find a solution to the problem. It just sucks this wasn’t found in testing and that we’re stuck with problematic systems in the meantime.

This doesn’t track.

I have a 2nd gen ATV 4K, which functionally decodes everything (except Atmos) to LPCM 5.1. It doesn’t deliver bitstream the TV/Arc at all in ‘auto’ mode. My PS5 does the same thing (LPCM 5.1 only). I am still seeing drop/sync issues, with all devices ONLY outputting LCPM 5.1.

Effectively, changing my Apple TV to force DD5.1 encoding would actually CAUSE me to be switching codecs when I change devices, not prevent it. Like I said, I’m still seeing the issue.

Also fwiw, YouTube audio is always decoded to LPCM by your player,  as it’s encoded in either Opus or AAC format. The Arc (and basically all soundbars and HT receivers) don’t support either format bitstreamed so it needs to be LPCM. Basically, playing YouTube videos won’t ever change the audio codec streamed from the player (always decoded LPCM).

Just curious, I know we’re experiencing this issue across many source devices but among those experiencing it, who doesn’t have an Apple TV at all? If not what devices do you have? 

I have an Apple TV 4K, but I experienced the delay from the surrounds watching a YouTube video on a Roku Ultra and experienced the Sub and surrounds dropping out using a Panasonic UB820 Blu-ray player.

As I said it’s speculative. I have a 1st gen Apple TV 4K and having audio set to 5.1 output instead of Auto results in no drops for me while navigating the various apps including Youtube on the Apple TV. I’m not sure if the newer model handles audio differently. However, I have an older Sony TV with the older HDMI ARC standard not the newer eARC. Honestly, there are so many variables. Have you tried setting it to 5.1. If you have a newer eARC TV then doing so would result in an audio downgrade I assume. Either way the problem is clearly with Sonos’ update from a little more than a fortnight ago. Never had any issues prior to that.

I agree, I see it on all my devices too, not just my Apple TV. Where I’m going is that I first saw the problem when I added a second Apple TV 4K to my setup. Then I ‘rebuilt’ my system and only plugged in a single Apple TV, no other sources and didn’t have a single dropout for a week. Then I plugged in the second Apple TV but didn’t really use it and went another week without a dropout. Then I watched some content on the second Apple TV (after two stable weeks) and re-triggered the issue and have been experiencing dropouts for a couple days since. Going to ‘rebuild’ again and leave only one Apple TV and no other source device connected and see if I stabilize again. Just trying to isolate what source devices might be connected to people’s systems to see if there are any commonalities. 

I don’t have an Apple TV at all, just an Nvidia Shield and using the built in LGCX apps, still getting the same sound drop outs as the ATV users.

I have an NVIDIA Shield Pro (2019) and I have been experiencing dropouts on my subs and surrounds since 14.6 was introduced. I don't own an Apple TV. I have an Arc, 2x Sub (Gen 3), and 2x Fives for my home theater setup. Very frustrating as it is almost unusable in this state. :(

I’m becoming more convinced this is related to Dolby Mat format. Nvidia shield and Apple TV 4K both use this format for some Dolby content. Found this on a Nakamichi (atmos soundbar manufacturer) support page related to nvidia shield: 

Dolby Atmos MAT audio playback:

Some content devices output Dolby Atmos audio in "Dolby Atmos MAT" format, a new audio format that adds Dolby Atmos metadata into lossless pulse-code modulation (PCM) audio. The content devices are designed to prioritize internal buffering for high quality video when playing Dolby Atmos MAT contents. Therefore, the buffering process might cause random audio cut-outs. This is reported by various users with content devices that outputting Dolby Atmos MAT format

Sure sounds familiar to me

Suspicious since the issue only began happening with 14.6 and the behavior starts with the sub and surrounds getting out of sync before dropping out fully. In my case, this produces a nasty echo. The Arc itself never stops outputting sound.

To be clear, I’m not suggesting this wasn’t introduced by 14.6. Just that it could be related to how Sonos devices interact with Dolby Mat devices. I haven’t experienced the out of sync issue myself yet, just dropouts in varying combinations of the sub and 2 surround channels. 

Gotcha. I just confirmed the issue is still happening after the update to 14.6.1. I tried watching Thunderball with DTS 5.1 and the surrounds desynched (by roughly 250ms) after 10 minutes. 

It is absolutely ridiculous that this has gone on as long as it has with no public acknowledgment from Sonos. How much longer is this gonna persist? A week? A month? A year? So disappointing. 

I think the lack of acknowledgement is really worrying. It a customer service thing at the heart of it as well. Are we all just going mad and the problem is really do do with out own setup?!?

Seems to be a growing issue in the web as well - but some reports are saying its going to get fixed.

https://www.sanechoice.cloud/sonos-when-customer-service-goes-wrong/

https://thenextweb.com/news/sonos-fix-stuttering-surround-sound-14-6-software-update

This is happening to me, too.  Apple TV 4K with the Arc, Sub and OneSL’s as surrounds.  Sub and Surrounds drop out but show connected and I power cycle the arc and everything comes back….until it drops out again.  VERY frustrating.  Hopefully Sonos gets their act together and gets it fixed ASAP!

Don't know if this helps anyone else but I had this issue a week or so ago I didn't power cycle the arc at first but removed and readded the sub and surrounds this worked but read this thread and power cycled the arc

The fault reoccured when I did this I then just removed and readded just the sub and the surrounds returned without any problems.

It was done before the latest update and I have had no further occurance since doing this 

I use apple tv, pc and xbox and watch mainly content bought from apple and prime on the apple tv

May work for others may not just thought I would share it

I have 2 arc systems but have only experienced this issue on the one in the living room which is really curious 

Wow @peterbault ! Are they similar in setup? i.e. surrounds and sub etc? This is really odd how one system can work just fine, but another is not.  There must be a difference somewhere…...