11 Mixers: Routing A higher spec. desk may have two or more 'sub-groups.' Sub-groups are an extra fader in between the channel strip and the main output fader.
They allow you to control the overall level of several instruments using only one or two faders.
On a desk with sub-groups, there will usually be a set of push-button switches for each channel.
These allow you to route each signal, either to a sub-group or straight to the main output of the desk.