Yes, connecting any single Sonos device (not a Sub or surround speaker) directly to your router with an ethernet cable creates SonosNet.

Read more here:

https://support.sonos.com/s/article/3209?language=en_US

I’ve found the Boost is a more dedicated device, so if you have WiFi interference, the Boost can help minimise that more than a speaker component wired to the router.

Try your system without the Boost to see how it performs. If you have no issues then great, but if you do experience any dropouts, add the Boost back in as the wired device.

Is the advantage you claim for the Boost possibly attributable to the placement of your Boost vs the placement of the speaker you cable connected?

I’ve always contributed the fact my Boost seems to work better on my Sonosnet than the cable connected Beam I used before, to the fact the Boost is more centrally located in my home.

No, in my case both of the wired devices were located in the same location. Previously, I had a WiFi only setup but was getting dropouts on Sonos Radio HD when it first launched. I moved a One and wired that to the router to create SonosNet. Dropouts still occurred, even changing SonosNet channel etc didn’t help. Sonos Support confirmed local WiFi interference (in the room where my router is, my iMac can locate 20+ nearby WiFi signals). Bought a Boost and replaced the wired One with the Boost. It didn’t stop the dropouts immediately, but within a day or two, I never had an issue playing Sonos Radio HD again and I contribute that to the addition of the Boost.

I thought the One with its more recent/updated wireless card (compared to Play:1, Play:3 etc) would have done the same job as the Boost, but I could not get Sonos Radio HD to play without dropouts when the One was wired.

Each local network environment is different so a wired speaker may be sufficient for others, but if there are still issues using SonosNet, I’d definitely recommend trying a Boost.

I haven’t been paying attention to Boost info since I wired a few Sonos and removed my boost.

I wonder if some of the newer generations speakers have better radios than the Boost. It used to be mentioned that the Boost had a bit better noise rejection than a speaker.

It would be interesting to add a Boost to your setup and then check the matrix to see if it is being used. I had no place I could put my Boost to get all my SonosNet speakers to connect to it. There were always better links to other wired Sonos from at least one, no matter where I put the Boost, due to their locations.

@Stanley_4 - Not all my speakers link to the Boost, but I’ve just left in in my system after I wired a couple of other speakers. I read on another thread your issue with Amazon Ultra HD choking your system. If you still have your Boost it would be interesting to see if wiring that back into your system helps with the hi-res Amazon stream. Tidal played fine for me at the time without a Boost, but dropouts with Sonos Radio HD.]

Re network matrix, last month I replaced my Kitchen Play:1s with Ones and noticed the inbound/outbound connection to the Boost for them increased, which makes sense as the wireless card in the Ones is better. The Ones in the Kitchen actually have a better inbound/outbound connection than the Play:1s I have in the same room as the Boost! 

I might experiment with the matrix tomorrow, replacing the Boost with a Play:1, then a One, to see how they impact on the inbound/outbound signals to the Kitchen Ones.

A useful article I found around the Boost was the following:

https://freetime.mikeconnelly.com/archives/6050

I pulled out the Boost, put it in the most central spot I had hookups to up Ethernet and power, running a firmware update now. 

OK, back with a fresh cup of coffee.

After about 10 minutes I looked at the matrix, a stereo pair of Play 3s, a Beam and One SL have connected to the Boost. My Play 5 g2 and another One SL are hooked to the wired Arc.

From past experience if I run temp wires to get it closer (15 feet no walls) to the two not using it the Beam will drop off, too close, actually between the two (12 feet) and the One SL will also drop, it may go to the Arc or a wired Beam, they are almost the same distance from it.

At 20 minutes nothing has changed (I did refresh the matrix snapshot) in the connections.

The frustrating thing here is that the Play 5 is my most listened to Sonos and it is impossible to wire. The spouse made that VERY clear. Probably wouldn’t help as I’ve seen the same Amazon hang on my wired Beam. If I can I’ll grab additional diagnostics to past to the other topic, hopefully from the wired Beam.