Making the Most Of Your Mixer
MG16/4, MG12/4 13
External Effects, Monitor Mixes, and Groups

4-1. AUX Buses For Monitor Sends and

Overall Effects

There are a number of reasons why you might
want to “tap” the signal flowing through your
mixer at some point before the main outputs: the
two most common being 1) to create a monitor
mix that is separate from the main mix, and 2) to
process the signal via an external effect unit and
then bring it back into the mix. Both of these func-
tions, and more, can be handled by the mixer’s
AUX (Auxiliary) buses and level controls. If the
mixer has two AUX buses, then it can handle both
functions at the same time. Larger mixing con-
soles can have 6, 8, or even more auxiliary buses
to handle a variety of monitoring and processing
needs.
Using the AUX buses and level controls is pretty
straightforward. The only thing you need to con-
sider is whether you need a “pre-fader” or “post-
fader” send. AUX sends often feature a switch that
allows you to configure them for pre- or post-
fader operation.

Pre/PostWhats the difference?

4
pre post
A “pre-fader” signal is taken
from a point before the
channel fader, so the send
level is affected only by the
AUX send level control and
not by the channel fader.
Pre-fader sends are most
commonly used to provide
monitor mixes.
A “post-fader” signal is
taken from a point after the
channel fader, so its level
will be affected by both the
AUX send level control and
the channel fader.
Post-fader sends are most
commonly used in conjunc-
tion with the mixer’s AUX or
effect returns for external
effect processing.
Pre-fader send for a monitor mix. The send signal is fed to the monitor power amplifier and speaker system.
The channel fader does not affect the send level so the monitor mix remains independent of the main mix. No
return signal is used in this case.
Post-fader send for external effects processing. The send signal is fed to the external effect unit—a reverb
unit, for example—and the output from the effect unit is returned to the AUX Return jack and mixed back into the
main program. The send level is affected by the channel fader so the effect level always remains in proportion to
the channel signal.
Channel
Fader
Master
Fader
AUX Send
Level
AUX Send Level AUX Return Level