Apple Logic Express 9 - Manual (Page 1159)

You can store multi-channel audio as interleaved or split channel audio files.
An interleaved audio file contains all channel information, stored in an alternating single
“stream.” This would be left channel, right channel, left, right, and so on.
Split channel audio files couple separate audio files, allowing you to deal with each channel
(file) independently. Two separate files are created, where one file contains the left channel
samples, and the other file contains the right channel samples. The files are generally
identified by a .L and .R suffix. The two files are linked, and are edited as a pair. You can,
however, disconnect them (in the Audio Bin), allowing each to be handled independently.
Logic Express, and most other audio applications, support the import and recording of
interleaved files when using Core Audio hardware.
A handful of audio applications (including Pro Tools) only support split file formats, and
will automatically separate interleaved files when you import them.
Tip: You should use interleaved audio files if your audio hardware supports them. Split
channel audio files require significantly more hard disk I/O performance.
This chapter covers the following:
• Importing Split Channel Files (p. 1159)
• Working with Split Stereo Files (p. 1160)
• Exporting Split Channel Files (p. 1161)
Importing Split Channel Files
Nothing special needs to be done to import either split or interleaved files into
Logic Express. What happens when you import such files differs slightly, depending on
the audio interface hardware in use.
When split channel files are imported, they are automatically converted to interleaved
files. If you want to add several split channel files simultaneously, Logic Express asks
whether all files should be converted at once.
1159
Working with Split Channel Audio
File Formats 41