1 CROSSFADERWhen on far left position, only sound from the left decks will be heard from the Master Output. When at far right position, only the sound of the right decks will be heard from the Master Output. In all other positions, the audio signals from left/right decks will be blend. 2 VOLUMEAdjust the Volume of each Mixer channel3 CUE/PFLUse these buttons to send the pre-fader audio signal of each mixer channel to the Headphones channel for pre-listening (connection at the front side).4HEADPHONES VOLAdjusts the level of the Headphones Output (connection at the front panel).5HEADPHONES MIXBlends the signal from the PFL-enabled Mixer channels and the Master Output in Headphones.6 COLOR FX ONEnable/disable the selected Color FX on each Mixer channel. When disabled, no Color FX will be applied, regardless the position of the FILTER knobs.7 COLOR FX KNOBApply the selected Color FX to a Mixer channel. No Color FX is applied (off) when the knob is at the center/middle position8 COLOR FX SELECTUse these 5 buttons to select a pre-defined Color FX. FX 1 : Reverb Color FX FX 2 : Loop Roll Color FX FX 3 : Noise Color FX FX 4 : Cut Color FX FILTER: High/Low-Pass Filter9 EQ HIGH/MID/LOW3-Band Equalizer. Use these knobs to cut/boost the frequencies of the Low(Bass) / Mid (Middle)/ High (Treble) Equalizer Band. No adjustment is made when the knob is at the middle/center position10 GAINUse these knobs to adjust the pre-fader output level of each mixer channel When the knob is at the middle/center position, the track will be at zero dB level (or any other value set in zeroDB VirtualDJ Options)11 EXTUse this button to send the signal from the Microphone or AUX Input to Deck 4 as a Deck Line InputSelect which external audio source (Microphone - front connection, or LINE - rear connection) will be routed to the Input of the USB Audio Interface.12 MASTER VOLAdjust the level of the Master Output (connection at the rear panel).13 BOOTH VOLAdjust the level of the Booth Output (connection at the rear panel).