HEADPHONES SPLIT. When set to STEREO, both sides of Headphones will output the same Cue or Master Outputs (depending on the MIXING knob. When set to MONO SPLIT, one side of Headphones will output the Master and the other the Cue decks.
HEADPHONES MIXING Use this knob to mix between Cue and Master MIX in the Headphone channel. When all the way to the left, only channels routed to Headphones (via the Cue buttons) will be heard. When all the way to the right, only the Program mix will be heard.
HEADPHONES LEVEL. Use this knob to set the volume to the Headphones Channel