78. Crossfader Assign: Routes the audio playing on the corresponding channel to either sideof the crossfader (L or R), or bypasses the crossfader and sends the audio directly to theprogram mix (center, Thru).9. Crossfader: Use this crossfader to mix between the two active decks.10. Channel FX: Use these buttons to apply Effect A and/or B to the corresponding channelwhile using Serato DJ. While using Engine or when the Input Selector is set to Line,Decks 1 and 3 can use FX 1 only, and Decks 2 and 4 can use FX 2 only.11. Sampler Volume: Turn this knob to adjust the volume level of the sampler in Serato DJ.12. Master Level Meters: These LEDs display the audio signal level of the master mix (sentout of the Master Outputs). These levels are post-Master Level, so they are an accuratemeasurement of the audio signal sent out of the Master Outputs.13. Master Level: Turn this knob to adjust the volume level of the Master Outputs.14. Booth Level: Turn this knob to adjust the volume level of the Booth Outputs.15. Booth EQ: Turn these knobs to boost or cut the high and low frequencies for the BoothOutputs.16. Mic Level: Turn these knobs to adjust the volume levels of the corresponding microphoneinputs. The Peak light next to each knob indicates the current signal level by its color:green (low), amber (normal/optimal), or red (maximum/peak).Important: The audio signals from the microphones are routed directly to the MasterOutputs.17. Mic EQ: Turn these knobs to boost or cut the high and low frequencies for thecorresponding microphones.18. Echo On/Off: Press this button to activate or deactivate the echo effect on themicrophones’ audio signal.19. Mic Echo Level: Turn this knob to adjust the amount of the echo effect on themicrophones’ audio signal.20. Mic On/Off: Press this button to activate or deactivate the microphones.21. Talkover/Post: Press this button to use the “talkover” feature, which automaticallyreduces the volume level of the master mix when you speak into the microphone.Press and hold Shift and then press this button to activate or deactivate the “post”feature. When on, the microphones’ signal will not be sent to the Booth Outputs.22. Phones Level: Adjusts the volume of the headphones.23. Phones Mix: Adjusts the software’s audio output to the headphones, mixing between thecue output and the master mix output.24. Split Cue: When this switch is in the On position, the headphone audio will be “split” suchthat all channels sent to cue channel are summed to mono and sent to the left headphonechannel and the master mix is summed to mono and sent to the right channel. When theswitch is in the Off position, the cue channel and master mix will be “blended” together.25. X-F Link: Press this button to link or unlink the Serato Video crossfader to the audiocrossfader.26. Deck: Selects which virtual deck is controlled by that hardware deck. The left deck cancontrol Deck 1 or 3; the right deck can control Deck 2 or 4.27. Shift: Press and hold this button to access secondary functions of other controls.