Soundbar crackling sound with optical connection

Why are you connecting an Arc with an optical cable, rather than using an HDMI cable which carries the ARC signal? 

Have you tried unplugging the PS4 to see if that’s causing some sort of interference? Or have you submitted a system diagnostic within 10 minutes of experiencing this problem, and called Sonos Support to discuss it? 

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the Support staff, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

Sounds super frustrating! If everything was working fine before and suddenly started crackling after connecting to the internet, it could be a software update or interference issue.

Since others have had this problem for years, it seems like a known issue that Sonos hasn’t fully fixed. Maybe check if there was a firmware update on the same day? If so, rolling it back (if possible) might help.

Totally get not wanting to go through endless troubleshooting. Sonos should address this properly—hopefully, they acknowledge it and provide a real fix!