Like other Home Theatre players, Beam can’t connect to 5GHz WiFi. Its 5GHz radio is reserved, to connect its surrounds/Subs.

WiFi compatibility is all set out in https://support.sonos.com/s/article/126

Thanks for that link… I have not come across that before.

Let’s just say that is not what is advertised from various resellers but it does explain what I am seeing in my network. Unfortunately 

It wouldn't be the first time that a reseller hasn't quite got the story straight. 

I believe some time beam can connect to 5ghz, its some update that made it not to be able anymore, I dunno? because the Sonos Boost sale is not doing enough? So if you have a Beam and Sonos One SL pair as surround, and recently update your router. Good luck! better throw your Sonos out the window on trying to re establish that connection, cause your Beam and Sonos One SL, will never see each other not until you buy your boost. If you reach out to support, they will advice you to connect one of the sonos to Ethernet, hence creating its own Sonosnet, then will advise you that one should be connected. It was marketed as a wireless setup, and not all house or rooms are capable of having one ethernet connection.
For the readers considering to buy Sonos, save yourself. buy other stuff

@michael022502 Great combination of misinformation and paranoia!

The Sonos soundbars have always had their 5GHz antenna reserved for the dedicated connection to the Sub(s) or surrounds, because of the technical reason explained above. No change that I know of.

The 5Ghz connection is made for the Beam and One SL to “see” each other when the Ones SL’s are used as surrounds. To group them you need the Beam to be on 2,4GHz.  You do not mention why you do not use 2,4Ghz, but that is still an option. So is cabling the Beam or indeed buying a (not to expensive) Boost.

The below relates to the problem you've brought up because the apps network wizard isn't very smart. A change on the router may require a full remake of your network in the app.

One significant problem I've experienced is when someone doesn't understand the 5ghz vs 2.4ghz connections. If they try to force a 5ghz connection by deleting the 2.4ghz connection from the app's network, this causes a catch 22 problem between the speaker and the app. The speaker will fail to connect to the 5ghz and cause the "manage network" wizard to error out, and the manager network wizard will continue to error because it sees the 5ghz network still on its list and thinks it's setup correctly.

The only way to fix this problem is to clear all the related networks on the list and start from scratch. That way the app thinks it's a new network.

Or just simply wire a Sonos product to the network. Those with non-portable Sonos products, operating on SonosNet, quite often run their setup with no WiFi network credentials stored at all in their Sonos setup (not showing in the Network Settings area of the Sonos App).

Although some other users, who have portable devices - Roam/Move, will quite often just add the 5Ghz SSID/credentials to that area of the App and have their portable products operating on just that band only.

They removed support. It definitely worked just fine on 5ghz when it first came out (the gen 2).

So when and why? Since the technical explanation for the soundbars not using 5Ghz seems valid I would expect some proof for your statement.

i was able to use it before and all connected in 5ghz and and was able to play spotify via sonos app on my phone thats on the same network. but after some device update. they cant connect anymore. what proof do you need? tech support mentioned now need to be wired. so how come im able to setup and use before without connecting to ethernet?

you can come to my place if you know better than giving response that has no value.

its unusable for 3 months already

 beam gen 2 and 2 sl1 surround.

I switched to T-Mobile home internet, and it is supposed to differentiate between 2.4 and 5.0 bands. I spent hours trying to get my Sonos beam gen 2 and my Sonos sub mini working. When I finally got the beam to work it was not recognized in the app. Same thing with the sub mini. My 2 Sonos ones connected but did not put out any sounds. I finally got the beam and sub working by connecting the ethernet cable but the sonos ones would not play any sound. I was literally pulling my hair out. Got on the phone with the sonos support guy and we were on the phone for an hour and 15 minutes. He took over my phone and it took forever to finally get the sonos ones to work. The ones finally worked surround with my fire tv cube but would not work with my Roku 4k stick. This is ridiculous for a system as expensive as this to be this difficult to set up!!!

So what was the cause of your issue? - in my own case my two Sonos Beams and their surrounds (Sonos Ones) were each setup without any issue.. it was a simple process. Was it something connected to your router/network? How were things fixed in your case?

I too was working like a champ on 5ghz network and now going to have to change up network settings.  The problem is most people live on the 5g networks so having to switch to 2g is just plain dumb.  Especially for a high end system.  I also realize it’s a small inconvenience, but still annoying

But maybe not when grouping speakers across different rooms and through walls, as the 2.4Ghz band is much further reaching and far more penetrating than a 5Ghz signal. Ideal for grouping when playing music, in sync, across many rooms/speakers.

The suggestion that "most people live on 5GHz" and the implication that 5GHz is intrinsically better than 2.4GHz are the only dumb things around here. 

It’s not 2G and 5G, those are cell phone networks, where “G” stands for “generation”. Wifi uses 2.4Ghz an 5Ghz radio frequency bands.

lol yes I know the difference between 2.4 and 2g.  Also, my point was why does Sonos require me to separate 2.4 and 5ghz bands if my situation doesn’t require.  In my case it doesn’t.  That said it could still allow for those with larger homes or other situations that might necessitate to use 2.4 GHZ.  And yes 5ghz is superior in close range, duh!   More importantly my footprint is not that big so I do not need 2 separate bands or networks broadcasting 

Why would you complicate discussions by using the wrong terms? I do not think most people “live on” 5Ghz networks. Most people let their router and devices decide what network to use, so for most people this would not be a problem.

I’m not sure it is technically possible for Sonos to program a switch to 2,4Ghz only in case 5Ghz needs to be used for the dedicated link Sonos uses for the surround and the Sub. You seem to word it as if Sonos is willingly crossing you. I do not think this is the case.

My router uses combined bands and that works okay for my setup - maybe the band steering on your router is nit doing too good a job, in which case separating them might be the way to go.. or just use SonosNet perhaps. There are many options that Sonis make available for you to explore and to try and see what perhaps works best for your setup, but a HT master device needs either a wired or 2.4Ghz connection to the LAN as it’s 5Ghz adapter is used for the much needed faster ‘direct’ connection with its bonded surrounds and Sub(s).

In my situation, I just received a new router from my provider. It turns out I went from 2.4 GHz to 5 GHz and now I cannot connect to my Sonos beam. Rather than getting a second router or trying to figure out how to get 2.4 out of my current router, can I use a cat five cable from the router to the beam and then progress as usual? I would love to hear thoughts on this.

I’ve not seen a router with just a 5Ghz band, might it still be a dual Wifi band router with band-steering? Each band is likely using the same SSID?

What is the make/model of the router?

Have you added the new WiFi credentials to your Sonos device?

Note, the Beam will require a 2.4Ghz WiFi to operate over your LAN, as it’s 5Ghz adapter is reserved for use with any Surrounds and/or Sub.

What do your new router configuration pages show in relation to your WiFi network?

And yes, you can connect the Beam with a CAT-5 cable, and continue as normal. 

I finally got hold of a cat5 cable and connect that to the beam. My Sonos ones are now connected to the beam. The hardest part was hiding the cat5 cable