Lost surround and sub ( after update ?)

So I posted an incident I just had where I lost the sub when switching apps, but flicking the sub off and on in the app had the actual arc directing all the bass to the Arc and then away correctly, but for some reason a moderator has to verify the post first, but I just want to add, that I was able to alleviate the problem by just rebooting the Apple TV.

I have made some progress. With some settings changes on the Apple TV and Sony TV I cannot currently trigger the issue.

On the Apple TV 4K:

- Force Dolby 5.1

- Force 16 Bit Sound Mode

On the Sony Tv:

- Digital Audio out: Auto 2 (output only compressed audio for Multichannel content without change)

- Dolby Digital Plus output: Just Dolby Digital, not plus.
 

Not sure why this helps. It does strengthen my thesis that the problem is codec switch related.

I am really worried that Sonos will turn this around into “hey, it’s the combo of the Apple TV and older Sony Tv that is the cause”, when this worked really well up until a few weeks ago when the 14.6 update hit… More so when the changes I have made are all quality degrading.

i should also add that I am quite confident that this is a good stopgap for me. I have been able to very reliably trigger the problem by pausing content, especially Apple Music spatial audio. Now nothing will break the 5.1 signal playback through all speakers.

Granted, I could be back with bad news in an hour or 10,  but it would still be a vast improvement as I previously triggered it in 2 minutes.

Hi All,

Sorry for delay - I had a lot of issues at work today so could not spend time during the day!

I have now completed the testing steps provided by the Engineer - which was to unplug everything from the TV except the ARC, and then play a couple of movies for 4+ minutes and send a diagnostic report.

The Engineer still wants to understand this CEC error. 

The error that I'm seeing on my end is that the CEC feature from the TV it has a false value for the ARC which should not happen and it has a true value for a different product that is connected to your TV, which might be the Apple box. 

Not quite sure what that all means to be honest, but he appears to be looking into this area.

Thanks,

Brad

I’ve mostly seen this issue trigger initially and destabilize my system when I have 2 Apple TVs connected and I switch back and forth. Not exclusively, but mostly. “false value for the ARC which should not happen and it has a true value for a different product that is connected to your TV” seems to track for me. I suspect others who mainly use tv internal apps might not identify with this as much though. FWIW my TV is an LG C1 if we want to establish this is happening across tv manufacturers so support doesn’t point to one tv manufacturer as being the culprit. 

My thoughts from the comment was that the Apple TV was attempting to steal away the CEC focus away from your Sonos ARC - have you perhaps tried the Apple TV with the CEC ‘TV control’ disabled in its settings, or is that something you tried earlier?

I tried it. Doesn’t help 

May I ask why you’d have 2 Apple TV’s connected? 

Another theory I had a while back is that the Apple TV is trying to steal the audio from the TV so it can play it to a HomePod (a feature that it possesses). Even if there’s no HomePod present and the Apple TV isn’t connected to an ARC/eARC port, it could be erroneously asking the tv for the audio explaining the error in CEC true/false value. Again doesn’t explain the issue for users not using an Apple TV or device with similar capability but seems plausible based on your info and my observations

The second is connected to my vpn router. Hasn’t been a big deal to live without it so I’ve mostly left it disconnected. Every time I try it again I trigger the issue and have frequent dropouts with any codec/app/source switching for a few days until I disconnect/reconnect and power cycle everything to restore stability. 

Based on my experience I am prepared to bet big on this being a format/codec issue on the Sonos side. Any takers? (See earlier post.)