DDJ RB - switching speaker modes?

 HI there,

I have just installed Rekordbox on my MacBook linked to a DDJ-RB.  On the setup I have selected the audio to come through the Mac's speakers.  This is all working fine, except that it is trying to send the headphone cues through the soundcard as well (which I don't want).

I want to cue the headphones through the DDJ RB headphone socket, and assume I can only do this if the speaker setting is switched to using the master outputs on the DDJ RB. 

However I cannot find a way to switch the speaker setting.  Presumably this in Rekordbox somewhere? 

Help is appreciated.

Darren