16 on-board effects are included for a wide variety of live mixing variations, ranging from common processors like "Delay" and "Echo" to more exotic sounds like "Ring Modulator" and "Vocoder". Multiple effects can be used at the same time via the "Effect Assign" function, allowing separate signals to be sent to the A and B sides of the crossfader as well as the mixer's "Master" channel. On-the-go processing is made available with the addition of two highly-responsive pots, providing "Rate/Time" and "Depth/Sweep" macro controls respectively. Effects can be enabled and quickly disabled through the use of a dedicated "Effect On/Off" button, with a separate tap tempo button enabling beat-matched results for time-based effects. Once triggered, a given tempo can be instantly spliced to 1/4, 1/2, 3/4 or double its initial speed for risk-free experimentation. Each of the four channels are equipped with a three-band isolator equalizer, with dedicated "Cue Selector" monitoring for quick accessibility to the distribution of a given DJ's mix. With a total of ten outputs and three inputs, the 004FXu can be configured in an endless number of ways for a truly customized live mixing experience.