I know this forum is kinda old but just wanted to post and let you know that the soundflower thing worked. Outputting Traktor Master to Aggregate Device Out 0 & 1 and Traktor Monitor to Aggregate Device 2 & 3. Soundflower 2ch. is set to built-in output. The aggregate device in Audio Midi Setup has my Mbox 2 checked and the Soundflower (2 ch.) Thank you everyone for your help, couldn't of done it without the good ol' internet and good people like yourselves.
The only thing that i can't figure out is how to boost the volume of my built-in-output. I can hear the cue'd track in my headphones, but it's at max volume on my computer and the headphone volume within traktor. Any ideas how to increase gain on the built-in output of a mac without buying an interface or mixer or something? some kind of software hack maybe? Gonna do some research now.
[url=http://www.macprovideo.com/forum/upload/upload/server/php/savedfiles/files/mpv_41852_235389_Settings_for_Mbox_Interface_Setup.png] [img]http://www.macprovideo.com/forum/upload/upload/server/php/savedfiles/thumbnails/mpv_41852_235389_Settings_for_Mbox_Interface_Setup.png[/img] [/url]