Change the gain of audio regions in Logic Pro for Mac - Apple Support

You can change the gain of audio regions with the Gain tool, or in the region or cell inspector.

Audio Editing settings in Logic Pro for Mac - Apple Support

Logic Pro X: Six Tips & Tricks

Logic Pro User Guide for Mac - Apple Support

Use multi-output instruments in Logic Pro for Mac - Apple Support

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Logic Pro for Mac inspector interface - Apple Support (ME)

Gain plug-in in Logic Pro for iPad - Apple Support

Use the I/O Labels window in Logic Pro for Mac - Apple Support

Work in the Cell Editor in Logic Pro for iPad - Apple Support

Change the pitch of an audio region in Logic Pro for Mac - Apple Support

Logic Pro for Mac Project Audio Browser interface - Apple Support (AE)

Gain plug-in in Logic Pro for Mac - Apple Support

Peak level display and signal clipping in Logic Pro for Mac - Apple Support