not getting sound through headphones on ddj-1000

i've looked up this issue everywhere on the internet. channel cue is lit but instead of getting sound coming from the headphones , the sound comes through my imac speaker. the fader is all the way down and still get sound through imac speaker. in preferences on the master output i have them set to output 1 and 2 on headphones output they were blank and the only options i had were also output 1 and 2. can someone help? i just got my controller a week ago and ive been trying to solve the problem but so far no progress.