Rekordbox DJ 5.3 audio settings - how do I get cue to only play through headphones, not master output

I recently downloaded the free trial of Rekordbox DJ so I could use the Performance function. I set up my xdj-700s as an aggregate unit, then went to audio preferences in Rekordbox, selected external mixer, and assigned my outputs. Great, now I have channel 1 on my Xone assigned to deck 1 and channel 2 assigned to deck 2. 

One major problem: when I cue a track on let's say channel 2, while the fader is all the way down - it plays through the master output so everyone can hear my mixing. How do I get the cue to only play through my headphones like normal?!