No.  The Line-In will insert at minimum a 75 ms buffer delay into the playback stream which makes it difficult to impossible to use the Line-In for any live performance such as DJ’ing.   

I’m not actually DJ’ing I just want to fade out one track from turntable 1 and fade in from turntable 2.

I just thought there must be a way ?

I appreciate your feedback.

Many thanks.

The Port is expecting a line level signal from any device. If you choose to push two turntables through a mixer, and feed the result from the mixer to Sonos, it wouldn’t know the difference.

Not quite sure why you wouldn’t just want to digitize the data, and use it without having the turntables and mixer involved, though. 

And I’ll reiterate @jgatie s warning, for anyone else thinking Sonos is a great speaker for DJing….it isn’t. Any and all Sonos analog line ins are subject to a minimum of a 75 ms processing delay, so that Sonos can prep the signal to be distributed in sync across the worst case scenario of a 2.4Ghz wifi channel. This is built in to the software, and can not be “turned off”. 

You could easily set it up as the mixer will give you the two inputs / one output you need.

The sound would be comparable to what you have now if the levels are set properly.

As said though there would be the delay issue which won’t be noticeable in playing music but if you tried to add a mike it would,

Thank you for your feedback Bruce.