Yep: set up the Five as a new room, and plug in the cd player (assuming it has a line-out connection). 
 

Then, use the Five’s Line-in as the source. It can play to the Five, or to the stereo-paired Ones, or both together using the Group feature. 
 

If the Ones are set up as surrounds, you’ll also get the sound through the Beam, as you’ll play to a “room” rather than specific speakers. 

Many thanks ​@nik9669a !

I’ll go ahead and find me a Five in that case.

Just to confirm, my pair of Ones are currently set up as a stereo pair with the Beam. I don’t want the Beam active alongside the Five as I’ve heard this is overkill and I can see why that could be the case

Thanks again!

JB

That’s fine. Any room (ie the label used to identify a single speaker, or a stereo pair, or a home theatre setup) can use the line-in from a speaker on the network.
 

In your setup, the Five could be streaming music in one room, whilst its line-in source is used by the Ones. 
 

If you have them all in a single physical room, the Ones plus the Beam and the Five might be overkill

So all these speakers - 2x One, Beam & Five, will be in one physical room (lounge), but I’ll only want the  Five & Ones to play from the CD.

Assume I can make two separate groups, just by creating two rooms. 

However, when you say ‘…line-in source is used by the Ones’ - these don’t have an input right?

Appreciate your help here!

The line in source is a socket on the Five, it can be selected as the audio source for any/all Sonos. 

You will set up multiple Sonos Rooms (dumb name choice) in your room. Each Sonos or bonded set (stereo pair or home theater set) will become a Sonos Room.

You can Group your Rooms together as you wish and then select what source that Group will play.

Thanks both so much for clarifying the plans in my heads with your clear & concise replies!

Just found a refurb Five online as well :)

Best,

JB

If you get tired of swapping CDs look into ripping them into a lossless format, like FLAC, that is easy to convert to other formats with no loss of quality.

Then load them into a NAS or file-share and insert the music library to play them.

Mine CDs are under a bed somewhere and I gave away the CD player years ago.

Thanks again all. Just to update,,,

I’m considering buying an Era 100 instead of the Five (Gen2 are still pricey) and then connecting this to my 2x Play 1’s & Beam, assuming they can all talk to each other? This setup will then be used for both my CD player via line-out, and my turntable via phono connections (4 speakers in total).

I’d still be using my Beam with 2x Play 1’s for my TV setup - (3 speakers in total) set up as a different room (but in the same physical room).

Am I right in thinking this would work? I appreciate your responses.

JB

Yes, it should.

Two things. There is no Gen 2 Five, only a Gen 2 PLAY:5.

As has been previously noted, the line in on your surround speakers is turned off…which doesn’t matter to you, as you’re getting another Sonos speaker to act as the line in to the Sonos system. The line in on your separate room can send the signal anywhere (room-wise) in your Sonos system, not just the Era 100. 

Think of Line-In as a network resource that can be played in any combination of Rooms. Line-In will not automatically play through the box where it physically connects.

So it turns out I can only group my Ones with a Five (I want a stereo pair)

Might just buy a Five for exclusive CD player use, or replace my Ones with ERAs and use the line-in on one of those for the CDs so at least I can get a stereo pair, although the latter option might disconnect the stereo option.

Why is it so complicated!

I think you may have misunderstood the above answers.

You can Group any of your Rooms with any other Rooms. Don't think speakers, think Rooms when Grouping.

You can have either a Stereo Pair with the Ones as a Room or use them as Surrounds for the Beam's Room. You can switch between these two options but it is a bit of effort.

Any Sonos used as a Stereo Pair can use the line-in if it has one, when used as Surrounds they can't. 

I'd consider the Ones as Surrounds for your Beam, a set of Eras as a Stereo Pair and (if you don't  use the Five's line-in they will provide two additional line-in connections (adapters required.)

It really isn't complicated, the pairing, grouping rules are pretty simple, as is the line-in usage.

If you have a streaming service that provides ATMOS I'd be really tempted to go for the 300s as the sound is amazing. Add a Sub or mini-Sub to the 100s or 300s and it is even better.

And just to be ‘super clear’, Sonos stereo pairs must be the same ‘named’ speakers. You can stereo pairs must any two Ones, or two Fives, or two PLAY:5s (of the same generation), etc. It might help to see the FAQ on Sonos terminology. most of the responses you see in this forum will be using those distinctions, particularly between ‘grouping’ and ‘pairing’, which in the Sonos environment are very different.