Apple Logic Pro 7 - Manual (Page 197)

Chapter 4 Audio in the Arrange Window 197
As long as your computer is able to calculate all active processes in real time, it’s
unnecessary to freeze tracks.
Freeze is recommended whenever your system’s power runs short and one, or multiple,
existing tracks with CPU-intensive instrument and/or effect plug-ins are in a finalized
state, or at least seem to require no further changes for the meantime—in other words,
a “close to final” mix.
As long as a track is frozen, its CPU usage is reduced to that of a high resolution audio
track, without any effect plug-ins inserted—regardless of the number, or processing
demands, of the plug-ins that were used originally.
How to Freeze a Track
It’s extremely easy to freeze a track: simply activate the Freeze button—the button
that features a small ice crystal icon (light gray when active). If the Freeze buttons are
not visible, activate the View > Track Freeze Buttons menu option in the Arrange
window.
If you hold Command while clicking on a Freeze button in the Track List, all tracks that
contain data in the currently-selected display level (or folder) will be frozen. If the
Freeze buttons were already enabled, they will be disabled.
You can also use track button slide activation to enable Freeze on multiple tracks.
Logic will create freeze files after receiving the next “Play” command. This allows you to
activate the Freeze buttons of multiple tracks, and render their freeze files in one go.
During the Freeze process, the SPL will follow the currently rendered position. A
floating progress bar window is also displayed.
Freeze files are always rendered between the song start and end marks—it is
recommended that you check the song end mark in the Bar Ruler before starting a
Freeze process. Please note that the end mark should be adjusted to include feedback-
dependent delay repetitions or reverb tails. Empty areas (digital zero) at the end of
freeze files will automatically be removed after the Freeze process.
You can abort freeze processes by pressing Command-Period—in this scenario, the
portion of the frozen tracks that has already been rendered will remain in the freeze
files, and will be used for playback. Frozen tracks will remain silent beyond this point.