Reply to playing music "thru" controller soundcard

Hey guys, does anyone know if it is possible to play music (say directly from itunes) through the soundcard on a digital controller (such as the s4) onto the speakers connected to the controller without using traktor pro2 software?

i bought a pair of krk's and am wishing that i could also utilize them with my desktop (right beside my controller set up which uses my laptop)

basically i wanna be able to play music on my krk's from 2 sources (computer and laptop; where only one has traktor installed).. i cant just connect extra wires to the desktop cause the krks dont accept 3.5mm

thanks