Reply to Headphones not working with traktor

I'm currently using traktor 2.5 with a Denon Mc3000, I have the Denon driver installed and everything. However, I can't use my headphones, as when I press cue the sound is still coming out from my speakers.

My speakers are connected to my comp, not my controller, so for audio in traktor I have it set to ASIO. I can't connect my speakers to my controller as

1) i have no idea how
2) i've plugged my speaker cord into a phone jack and into the MASTER OUT socket L and tried R (on the back of my controller) but no sound comes out. I did this with switching the audio from ASIO to the denon soundcard audio, still no sound

When i change my audio from ASIO to the denon audio driver, with my speakers still connected to my comp, no audio comes out.

I tried connecting my headphones to my speakers whilst connected to the comp, nothing happens.

EDIT:

Also, does anyone have a problem where traktor just randomly stops responding? Seems like a big deal considering you never ever want this to happen..