The solid white light when first plugged in is odd and that should only be the case once the product has been successfully added to your system. You should have had a flashing green light to begin with. 

Maybe try doing a factory re-set and try again - hopefully it will flash green this time?

I also had a similar issue today when I received mine. (No sign of it being discovered and white light came on and steady). 
I resolved it by:

1. plugging in a network cable directly from my router to the Mini Sub
2. restarting all my Ethernet switches
3. Restarting my router
4. pushing and holding the ‘connect’ button on the Mini Sub.

TBH I’m not sure which of these made a difference but it eventually came up in my app! I wish I could be more scientific for you!  

Thanks for the replies - glad someone else has had the same issue!

@mikiesoft I’ve tried all those bar restarting the router - partner and I are WFH so need to wait a bit to try that.  Fingers crossed.

I’d recommend starting with number 4 first, the other three may not be necessary. 

Essentially, you’re doing a factory reset on the device, so that it can be properly set up.

And no, I have no idea why the device is being shipped in this state, but setting up ‘clean’ is always a great option. 

Thanks all...factory reset did the trick. Holding the join button as the device is plugged in. Wait for the Orange light to flash. After a moment this got the sub into its flashing green state. It then immediately appeared in the app.

Go well!

Glad it worked out for you

Just came here to add that I too was unable to connect my newly delivered sub mini today to my existing SONOS system without first doing a factory reset on the sub mini (hold the join/pair button on the front of the sub whilst plugging into the mains and wait for the light to flash orange/white)

As soon as I did this the sub was immediatly detected by the SONOS app and I was able to connect it to my system. Prior to doing this the SONOS app just showed the wifi searching icon and it didn’t detect the sub. Never had this kind of problem before. Kind of seems like the sub came from the factory already configured to a system?

I’m imaging someone in QC forgot to do factory reset after testing?

I’m imagining the same thing. ;) 

Certainly worth someone at Sonos poking into the concern. 

Did the “hold the join/pair button on the front of the sub whilst plugging into the mains and wait for the light to flash orange/white” till it turned flashing green & showed up in the app. Still waiting for the ‘code scan’ the app requires from the top of the unit. This setup process has taken me about an hour ( 30 mins after I did the reset as shown above.) Still not connected.

You may want to call Sonos Support directly to discuss it, it shouldn’t be taking that long, I’d think.

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

Yes, the same happened to me - the sub-mini did not initially boot to a flashing green status LED, just a plain steady white LED and of course initially did not allow first-time setup. 

I realised it just needed a quick factory reset and did that. It then setup with no other issues seen. I did take a diagnostic report post-setup: 1217586889.

The sub has been working just fine ever since. No complaints and it sounds fantastic (everything currently at default settings) with a Beam (gen1) and surrounds. It really does make a huge difference to both TV and music audio.

If you perhaps have a case/cover on your mobile controller device, then perhaps remove it as the NFC setup can be blocked by some device covers. I chose to place the back of my mobile (iPhone XR) less than 1/2” from top of Sub and moved it around the Sonos logo - it soon communicated and the setup was completed inside a minute… otherwise there is the option to complete the setup with the 8 digit pin-code that’s printed on the bottom of the Sub.

Finally connected! Hope this is the last & final issue with this new sub!

Let's be honest though, this isn't good and is quite an oversight from Sonos.

Really shouldn't have happened and shouldn't have ‘just' needed a quick factory reset, the thing that is posted so often not to do without being instructed to do so.

I do agree - my Sub-Mini looks like it was put together in Malaysia and I suspect whoever installed/tested the software, either forgot to do the reset, or didn’t hold the join button long enough.

In the hands of ‘existing’ Sonos users it is easy to resolve of course, but I guess there might be a few people purchasing the sub who are new to Sonos and might need to seek support. I think the fact it’s now mentioned here in the community might hopefully help to reduce any potential support calls. That’s if anyone else has this software issue.

On a much brighter and positive note, I have to say the Sub-Mini really does sound excellent for its size - I’m extremely impressed by it. It gives a lovely warm deep tone to our bedroom Beam HT setup. Very nice indeed.

Glad I found this site as it certainly solved my connection problem. Very disappointed after waiting for delivery then trying to get it to connect for about 8 hours, and no joy.

So thank you all for the help and satisfactory outcome,  and a great product. 

I picked up my Sonos sub mini today.

It paired up using the Sonos app and it said everything was ok. It also did a software update. The light was also on. 

I sat down to listen to a few things and thought ‘there’s no bloody difference’. Boo. I checked all of the settings and all was in order. I then put my hand on the speakers and they were still. There was no response to moving the settings in the app. Hmmmm… DOA?

I switched the connection on the sub from wireless to wired and restarted the Beam 2 and Sub Mini by unplugging both. 

All was in order then. She’s pumping out sweet bass and responding to the app controls. 

Here’s a page of songs to test it on. 

https://www.whathifi.com/features/25-best-tracks-testing-bass

My sub mini is showing connected as part of a beam 2 and 2 SL surround system- but there is no bass/ sound coming out of it- it shows as connected, and has an ip address. Adjusting the level does nothing either. Have unplugged and plugged back in etc. Nothing seems to be working. Hoping that an update fixes this… have a house full of sonos products, but this has been a real pain. 

I’d recommend submitting a diagnostic, and calling Sonos, assuming your testing with a 5.1 source being fed to the Beam. 

Are you perhaps playing a PCM 2.0 stereo audio source from the TV? What does the label show on the ‘Now Playing’ screen in the Sonos App?

Why is this a problem for everyone? This is pretty poor service for a product to ship in this state.

It’s not a problem, just a couple of teething issues with the initial pre-order. All has been fine since. I don’t know why you would think otherwise?

Because I just received one, tried to work out the problems and then came here. Perhaps it could of been resolved or noted before now? This thread started a few months back.