Apple Logic Pro 8 - Manual (Page 215)

Chapter 10 Working With Instruments and Effects 215
The Plug-in menu offers additional information about an output configuration. As
examples:
 Instrument Name: Multi Output (2 x stereo, 4 x mono)
 Instrument Name: Multi Output (4 x stereo)
Note: Not all instruments (Logic Pro or third-party) are multi-output capable. If the
instrument does not provide a Multi Output option, it is not equipped with multiple
output facilities.
To insert and set up a multi output instrument:
1 Choose the desired multi output instance in the 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 aux channel strips.
2 Within the instrument interface, you will need to set up the output routing for
individual sounds or samples. This is generally done via a menu, that shows entries
such as: Main, 3-4, 5-6, and so on.