Do you have 802.11n  enabled or just ac?

.. and your SSID is broadcasting, right?

@John B : Hm, I’m not sure, is this something I need to set on my router?  

The description of Sub states: “Connect to WiFi with any 802.11a/b/g/n 2.4 or 5 GHz broadcast-capable router.”, so it sounds like they’d all be supported, but maybe my router is broadcasting something different?  

@el rubio: Yes, I have other sonos products in the same room connected to wifi, laptop connected, phone connected, etc.  Laptop and phone can see at least 10 5ghz networks; sub can’t see any.

Actually having checked it looks like Sonos should support a and n protocols so it should be finding it.

@ChrisGM How are the rest of your Sonos devices connected? Your profile lists a Connect:Amp, and that can only use 2.4GHz.

@ratty Sorry about that; I’ve updated my profile now.  I used to own a connect:amp, but sold it a few months ago and I’m in the process of updating my whole system.  I have 2 Sonos Ones in the room that are connected to 5GHz.  

When I set up my home network (I recently moved to a new home), I chose to only use 5GHz as I found it annoying to have devices trying to switch back and forth.  So I’m not broadcasting any 2.4 GHz.

I had a similar thought... and I could have sworn a C:A was there. But it seems to have gone.

Okay… although the Sub says it uses 5GHz WiFi, in practice it connects via the master HT player in an HT setup.

What I’d suggest you do is temporarily wire a device (not one of the surrounds) to the network. Wait 5 mins and everything should switch to SonosNet mode. You should then be able to add the Sub without problem. 

Once the Sub’s added, disconnect the temporary network cable. Wait another few mins and hopefully all will be well.

@ratty 

Okay, awesome!  I will try that tonight, thank you so much.