Sometimes a power off/on of all devices, including the TV, for a few minutes can clear such issues, but if it re-occurs, then immediately submit a Sonos system diagnostic report from within the Sonos App, note it’s reference and then contact/chat with Sonos Support Staff via this LINK and see what the Staff can perhaps suggest to resolve the matter.

I would also check that all HDMI cables are correctly seated whilst you do have everything powered off.

Thank you Ken for your reply.

I will do that later and report back!

Would you recommend that I also somehow factory reset the Arc?

thanks

No, do not factory reset anything at this stage, as it will wipe any diagnostic data - I would chat with Sonos Support before taking that route.

Ok will do, thanks a lot  

Hi all

Just to share my experience so far:

I powered off all devices as mentioned here, and for a few watches all was fine.  However over time, the popping returned - and I’ve also had audio drop outs too.   Example:  my children are gaming on their PS5 - and suddenly they lose both sound and picture - almost like something resets - and 3-4 seconds later it comes back on (much to the frustration of the kids - as they’ve conceded a goal or something and all hell breaks lose!).   The subtle electronic popping/plopping noise still happens e.g. when watching movies - mostly on Dolby Atmos content, but not exclusively.

I have submitted a diagnostic report each time this occurs - and taken a screenshot of the number, as most of the time it happens when I have time to watch something - usually when Sonos customer care hours are over.

I called Sonos yesterday and was on a call for 1 hour whilst they asked me to play various content and we tried to replicated the noise.  It didn’t happen whilst on the call (typical!) - and the test they asked me to do was to unplug all HDMIs/devices and power everything down.  Then after 1 minute, turn on TV,  then turn on 1 device at a time - and test each one if/until the popping comes back.  It was working fine whilst just having the Arc and TV playing Atmos content (I tried something from Apple TV via the LG TV).

However, I remember reading in another thread that disabling “CEC” on all devices got rid of the popping. This I’d previously done - but what I noticed is that when connecting the PS5 - it automatically puts back on “Simplink (HDMI-CEC)” on the TV.  Even when I go to PS5 settings and disable the “HDMI Device Link" - I try and turn off Simplink from the LG TV, it automatically toggles back on after 0.5 seconds; cannot seem to keep it turned off.

I then powered down and unplugged everything, turned on TV, then soundbar, but kept PS5 off - and Simplink CEC keeps “off” and all sounds ok.  But I know later when the lads use the PS5, it will automatically turn on Simplink setting on the TV - and it seems that stays on (even after PS5 is turned off), until I power down and unplug all cables (not great).

It’s hard to see who’s “problem” (apart from mine!) this is:  LG TV, Sony PS5, Sonos Arc - but I think this seems to be causing the issues  :(

Simplink (LG’s version of CEC) needs to be ‘on’ for control of the TV volume etc. That’s assuming you are using an HDMI connection… If you do switch off CEC on your connected devices, like Apple TV/PS5 etc; then I would power them off and on again to sort the ‘handshake’ between the devices - Apple TV can be really stubborn until it’s rebooted. 

Thanks for the reply Ken

Because I’ve read the CEC can cause this audio popping on the arc - I’ve tried to disable CEC on every device.  I managed to still be able to control the volume of the TV (coming through the arc), but still disabling CEC, but then pairing my SkyQ remote control with the Sonos app (via the “remote control setup” option) - which worked ok.

Everything is indeed using a HDMI connection (with the Arc using the earc port).

After disabling CEC on the PS5 (i.e. turning off HDMI link) - even after powering it off….whenever I then turn on PS5 - it seems to automatically turn on the Simplink on the LG TV (even when the PS5 still shows HDMI link is off from the sound menu). 

I don’t think the Sonos Arc or the ARC (audio return channel) will work over HDMI unless Simplink is ‘on’ - I would just switch off CEC on your ‘other’ connected devices for now.