Problems with audio on mac high sierra with rekordbox and xdj rx

Hi,  I am having problems with the sound on rekordbox using the XDJ RX with Mac High Sierra.

When I first connected the XDJ RX it asked if I wanted the sound output through the XDJ RX or the mac, I selected the mac as it was convenient for how I was connected at the time but cant find a way to reverse this when I'm outputting from master when playing.  Can still play off USB in standalone mode with Rekordbox disconnected but then cant use DDJ XP1.

Any ideas?