Logic Pro X: Freeze tracks
When Show Advanced Tools is selected in the Advanced preferences pane, you can freeze a track, reducing the processing power needed to play the track. Freezing a track reduces its processor usage to that of a high-resolution audio track with no effects plug-ins, regardless of the number or complexity of the plug-ins actually used on the track. Freezing is particularly useful for software instrument tracks and for audio tracks that use complex effects. Freezing is not available for multi-output software instruments.
When you freeze a track, the track is bounced to an audio file. The freeze file includes the output of any plug-ins on the track and any track automation. While the track is frozen, the freeze file plays back in place of the original track, which is temporarily deactivated (including any plug-ins). Channel strip controls (such as track mute and solo) are available, but no track content can be edited (including region mute and solo, for example).
While a track is frozen, it cannot be edited. If you want to edit the track, you can unfreeze it, make the changes, and then freeze the track again.
Freeze is designed to circumvent very CPU-intensive processes, such as software instruments with a complex voice architecture, and complex plug-ins (such as reverbs, filter banks, or FFT-based effects). If your computer can calculate all active processes in real time, freezing tracks is unnecessary. Freezing tracks is recommended when tracks with CPU-intensive software instrument or effects plug-ins are in a finalized state, or require no further changes.
By freezing tracks, you can:
Use extra effects plug-ins or software instruments in additional audio or software instrument tracks, which would normally be impossible as it would exceed the CPU-processing limits of your computer.
Play back projects created on computers with greater CPU power.
Freeze a track
Click the Freeze button in the track header.
The lock turns blue to indicate that the track is ready to freeze.
In the Track inspector, choose a Freeze mode:
Source Only: Freezes the track signal without any effects plug-ins. When selected, the Freeze button becomes solid.
Note: This Freeze mode is useful when using processor-intensive software instruments or flex modes.
Pre Fader: Freezes the track signal including all effects plug-ins. When selected, the Freeze button shows a dot.
Click the Play button in the control bar.
To unlock the track, click the Freeze button again.
To change the freeze state of multiple tracks, click-hold the Freeze button of one track, then drag the pointer up or down. The Freeze buttons of all swiped tracks switch to the same state.
If you try to make changes to a frozen track, a dialog tells you that the track is frozen.