User guide

Chapter 25 Mixing 591
After inserting a software instrument plug-in, the instrument channel can be accessed,
or driven, if you prefer, by MIDI regions on one or more Arrange window tracks. These
tracks are routed to the instrument channel.
Software instruments inserted into an instrument channel can, of course, also be
played directly from a MIDI keyboard, provided that a corresponding Arrange track
(one that is routed to the instrument channel) is selected.
The instrument channel type can also receive MIDI data from other sources, such as
Environment objects. This is useful for creating sound layers of hardware MIDI
instruments and software instruments, arpeggiating the instrument, and more.
Accessing Multiple Software Instrument Outputs
Logic Express supports the multiple outputs of the EXS24 mkII, Ultrabeat, and all Audio
Unit instruments. One or more multi output options may be displayed in addition to
the mono and stereo versions shown in the Instrument Plug-in menu.
The first two outputs of a multi output instrument are always played back as a stereo
pair by the instrument channel that the plug-in is inserted into. Additional outputs (3
and 4, 5 and 6, and so on) are accessed via auxiliary channels. Please see “Accessing
Multiple Instrument Outputs” on page 223 for more information on how to set up multi
output instruments.
Auxiliary Channel
Auxiliary (or aux) channels can be used as send returns, sub groups, and as additional
destination channels for multi-channel (multi output: software) instrument channels.
When you assign aux channels (as sends, for example), more are automatically made
available. To explain: When four aux channels are in use, a fifth is automatically created
when assigned.
Creating Auxiliary Channels
Typically, you will create aux channels as you need them. There are three ways to do
this:
 An aux channel is created automatically when a send assignment is made from a
channel strip.
 When a multi output instrument, such as the EXS24 mkII is inserted into an
instrument channel, several aux channel assignments are made “behind-the-scenes.”
It is up to you to create the required number of aux channel strips. This is done by
clicking on the plus button (“+”) at the bottom of the instrument channel. Each time
you click it, a new aux channel strip is created (and automatically assigned to
particular instrument outputs).