Certainly, this could be a failure mode of SUB, but also stay alert for unexpected correlations.

I was working with an audio unit in the electronics shop on a military base. During final test I noticed a periodic rude noise emitted by the unit. I was devastated and annoyed. After a few minutes, out of the corner of my eye, I noticed a large rotating radar array outside the building. Each time the array swung in my direction there was a rude noise.

Then I’d recommend following the suggestion in the post previous to yours!

I’m getting Same issue and need help !!

In that case I suggest that you perhaps contact/chat to Sonos Support Staff via this LINK. Hope you manage to get it sorted.

Hello I tried but issue did not get resolved ; as soon I plug my sub to power outlet it started making beeping noise.

Have you tried any troubleshooting at all to try to resolve the beeping noise? Just some examples:

• Powering it off for 3 minutes to see if that solves the issue?
• See if using a different power socket elsewhere in the Home makes any difference?
• Tried the Sub ‘bonded’ to a different Sonos Room. (If available)?
• Tried a different Power cable (if available)?
• Tried different audio sources?
• Tried it both wired to the LAN, aswell as wireless?
• Factory Resetting the device (as a last resort)?

If not, then perhaps give those a quick try to see if it might just resolve the matter.