Hearing the control tone


I just purchased the DS1 and when I hooked it up, I got the control tone out of the left deck. I hear the track clear as day on the right side but I hear the control tone in the background of the left side when playing a track. I am using Pioneer DJM-450, PLX-1000. The setup plays with no flaws through RB, I was hoping to be able to go back to Serato. Any help would be greatly appreciated.