When AMP is used to drive surround speakers its SUB and Line-In capabilities are disabled. In a surround Room the SUB is managed by the front AMP or soundbar.

As a guess, there’s just enough wifi interference to cause issues with the Sub’s connection between itself and the Amp. If the data in that FAQ doesn’t help, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it. Don’t post the resulting diagnostic number here, they get sensitive about GDPR.

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.

The Sub works of a 5Ghz connection with the Amp or soundbar. It seems the Amp has trouble keeping up the connection. Is the Amp further away or behind walls?

Hi all,

Thanks a lot for all the replies, very helpful!

I wasn’t aware that the sub and the amp would connect directly. The sub is in my living room, the amp is in my basement in a rack with all the network equipment. So while the Sonance speakers are in the living room as well, they are wired to the amp in the basement. My Wifi connection is good throughout the house, but I didn’t realize that the components need to connect directly, not over my home wifi?

Would it help, if I connect the amp in the basement to the network with an ethernet connection? 

Cheers and thanks again!

Edit

I could probably connect both sub and amp via ethernet to the router, but it’s not as easy wire them directly to each other. Will see if I can use the existing wiring of the house somehow…

Thanks for the infos. I now understand the system much better. My problem was, that I expected to add the sub just like standard Sonos speaker into a setup (“room).

​@DerSeb 

Here’s one more option...sort of try it and return it if not to your satisfaction.

1. Purchase an Era 100 to place in the room with the four in-ceiling speakers
2. Bond the sub-mini to the Era 100
3. Create a Saved Group following the direction in this link
4. Place the sub-mini in a spot that compliments the room

Know that the Era 100 will always play; so, place it in a spot where you think it will do the best without distraction.

No, you would never connect the Sub via Ethernet to any other Sonos. The signal doesn’t work that way. Each Sonos device needs to connect to a router.