Sampler and the Logic Pro Audio File Editor work seamlessly together. While you will typically perform most sample editing tasks in the Zone pane, you have the option of performing edits and adjustments in the Audio File Editor or an external audio editing application.
See Overview of the Logic Pro for Mac Audio File Editor and Sampler settings in Logic Pro for Mac.
By default, the Logic Pro Audio File Editor is opened when you use the Open in Audio File Editor shortcut menu command in the Zone pane. You can override this behavior by choosing a different audio file editing application as the default.
In the Logic Pro Audio Settings window, click the File Editor tab.
Click the External Sample Editor field to open a Finder window.
Browse, and select, the audio editing application you want to use, then click the Choose button.
The path and name of the application is shown in the External Sample Editor field.
Click the Remove button below the External Sample Editor field to restore the Logic Pro Audio File Editor as the default.
In Logic Pro Sampler, Control-click the waveform display in the Zone pane, then choose Open in Audio File Editor from the shortcut menu.
Tip: You can also use this command to open an external sample editor that you have set in the settings.
In Logic Pro, after the sample is opened in the Audio File Editor, drag the sample (region) and loop borders graphically in the Region and S. Loop rows below the waveform. The region length is represented as a red bar. The loop length is represented by a yellow bar.
To accelerate your workflow, you can also use the Audio File Editor loop commands:
Sample Loop → Selection: The loop area—defined by the loop start and end points—is used to select a portion of the overall audio file.
Selection → Sample Loop: The selected area is used to set the loop start and end points.
Choose Edit > Write Sample Loop to Audio File.
The new loop values are written to the audio file header.
Save the sample after you complete your edits.
The new values written to the audio file header are used by Sampler.
Note: Edited samples may have values that are not accurately shown in the Zone pane.