dj mixer

The vinyl turntables audio in to the mixer in separate channels, the mixer audio outs to the Sonos Port. The mixer also separately audio outs to the headphones so you can cue in the next tune. The headphones aren’t driven by Sonos at all. 

Gotcha.

Personally, I’d have a hard time dealing with the audio difference between the outside world, and the headphones, but if they’re blocking out all outside sound, that might work. But audio / music only, the moment you added voice (microphone of any type), people are going to be unhappy. 

It’s not something I’d recommend, in any case. Sonos just isn’t designed for this kind of use. I’m with ​@jgatie