A Sonos Port supplies a line level output via RCA jacks. 

Can’t you use AirPlay w/ the Kef ? 

Looks like it will have to be

Just looked at that, there has to be a better way

I have the Sonos App on my iphone, Mac etc, its nice , I click Apple Music, Radio Shows, select my preference and it plays on the Sonos speakers.

If i have a Sonos Port, RCA to 3.5 Aux - will I have my LSX2’s play the selected music???

Check with KEF with respect to attaching PORT L/R to one speaker and having this speaker transmit the other channel to the other speaker. Otherwise you’ll need to connect each PORT output to its speaker.

Thanks, good thought, however the LSX have inputs on only the master speaker, which is one of its plus points.

I will go the Sonos Port route as I like the Sonos app.