The MIDI button accesses the ProMix's extensive MIDI capabilities. Probably most impressive is the ability to turn the ProMix into an automated mixer. Using a MIDI sequencer, all mix parameters can be controlled in real time. MIDI program change codes can be used to select mix scenes, and all parameters can be assigned to MIDI controllers. MIDI dump can be used to save mix scenes to an external storage device.
Press the GROUP button for another nice surprise. Because the faders are motorized and computer controlled, they can be grouped together to provide simultaneous control of several faders by moving just one fader. Program up to four individual groups per scene. You might think this is a nice way to handle stereo inputs on two mono faders. You can "group" them if you want, but that's what the PAIR button is for. When adjacent channels are "paired" with each other, not only does moving one fader also move the other, but adjustments made to EQ, the sends, fader on/off, and other functions are also paired. Excellent!
The ProMix utilizes the graphics capabilities of the LCD display to provide full metering of all input channels as well as Send 3, Send 4, Return 1, and Return 2. Press METER to get a display of the levels of the sixteen mono channels. Press the right cursor key to switch to the other meter screen which displays the stereo input levels and the levels of the sends and returns. A peak hold function is available and can be turned on and off.
Press the PAN/Ø button to set pans and phase on each channel. There are graphic displays of "pan pots" for each channel. When channels are paired, their graphic representation shows a single dual-concentric control, and the "stereo width" of the signal can be adjusted. Press the CUE button to set the ProMix's monitoring mode. The Cue signal is fed to the MONITOR OUTPUT and PHONES output jacks and can consist of "soloed" channel signals or the stereo mix.
The COMP button accesses the ProMix's dynamics processing. There are three internal dynamics processors. They can be "patched" to any of the input channels as well as the sends and stereo outputs. Each processor has ten factory programs to select from, and there are ten memory slots to store modified programs you wish to keep. Six of the ten programs are compression programs, two are gates, and the other two are ducking programs. Each program only has five parameters, so there's little to learn about editing the programs. The LCD display provides metering for gain reduction and output level as well as a graphic display of how the output level changes relative to the input level.
There are four SEND buttons labeled SEND 1, 2, 3 and 4. The ProMix has two internal digital multi-effects processors. They are fed with SEND 1 and SEND 2. When SEND 1 is selected, the RTN/SEND fader becomes the level control for Return 1; likewise, it's the fader for Return 2 when SEND 2 is selected. SEND 3 and 4 can be used as sends for external processing. When SEND 3 or 4 is selected, the RTN/SEND fader becomes the master send level control for the selected send. The stereo input or any of the mono channel inputs can be used for the return signal. All four sends can be configured either pre or post fader.