Procedure

What is it? 

The patch matrix allows a physical, analog input to be routed to a channel other than the one it is assigned to by default. This may be useful to rearrange the mixer's layout. 

Example

Let's say you've got audio coming from video gear and you want to use the mixer's line inputs (25, 26, 27, 28) because they can accommodate the high signal levels that some broadcast gear outputs. But you'd like the controls for these inputs to show up on fader bank 1-8. The Patch Matrix allows this rerouting. 

Additionally, a single analog input may be routed to multiple channels. This is known as "multing". 

Let's say the band does a song where the singer goes to a "telephone voice" or part of the song. The Patch Matrix can connect the singer's microphone input to two channels. One can be set normally while the other is adjusted to sound like the singer is talking on a telephone. Then the singer's voice can be switched between the two using the channels' mute buttons.