Hi

The Cabasse sub (shown in the link) is a self-contained system that you attach Cabasse speakers to. Normally I’d say no however it appears it has RCA/Optical inputs which could potentially allow you to connect a Sonos Port (RCA/Optical outputs) to send Sonos audio to it; but not in reverse.

https://www.cabasse.com/cabasse-reveals-the-pearl-sub/

For the turntable….

You’ll need a Sonos speaker with line-in such as a Five, Era 300 or Era 100. You could also use a Sonos Port. The Era 100 is the best option. If the Turntable doesn’t have a built-in pre amp you’ll need to purchase a 3rd party pre-amp to fit between the turntable and Sonos component.

Edit:

If it’s possible to use a Port with the Cabasse sub you could use the RCA inputs on the same Port with the Turntable.

Hello,
Thank you for your reply concerning my Cabasse cabinet.
I'm going to look into the possibility of sending the signal to the subwoofer through the optical socket on my Beam... nothing ventured, nothing gained!
On the turntable side, I bought a Sonos ROAM which is bluetooth and picks up the bluetooth signal from the AKAI turntable.
Happy holidays from Toulouse/France
Mick

Mick, 

The optical port on a Beam is an input, not an output. You won’t be able to use that to send any signal, I’m afraid. 

But happy holidays, nonetheless. 
 

Mick,

Le port optique sur un faisceau est une entrée, pas une sortie. Vous ne pourrez pas l'utiliser pour envoyer un signal, j'en ai peur.

Mais joyeuses fêtes, néanmoins.

The Beam only has an HDMI-input: it has no optical output (let alone an output). It comes with an adapter that will connect TV with an optical output to the HDMI input on the Beam.

Great point, I was indeed thinking of the optical input on my PLAYBAR, and not really the Beam itself. In either case, there is no output on any Sonos soundbar. 

Good