Work with the master track in GarageBand on Mac
Each GarageBand project has a master track. When you show the master track, it appears below the last track in the Tracks area.
You can control the overall playback volume of a project using the Volume slider in the control bar or on the master track. Both sliders act as a master volume control for the overall project.
Generally speaking, you should adjust the output volume to a level high enough to eliminate background noise, but not high enough to cause clipping. You can check for clipping by watching the clipping indicators in the master level meter.
You can easily add a fade-out to the end of a project, so that the sound gradually fades to silence. When you add a fade-out, four volume points are added to the master track for the project. The first volume point is added 10 seconds before the end of the last region in the project, the second at 7 seconds, the third at 4 seconds, and the fourth at the end of the last region.
Show the master track
In GarageBand on Mac, choose Track > Show Master Track.
The master track appears below the last track in the Tracks area.
Add an automatic fade-out
In GarageBand on Mac, choose Mix > Fade Out.
Adjust the length of the fade-out
In GarageBand on Mac, choose Track > Show Master Track.
Choose Mix > Show Automation.
Choose Volume from the Automation menu in the master track header.
Move the volume points at the end of the master volume automation curve to adjust the length of the fade-out.
Manually add a fade-in or fade-out
In GarageBand on Mac, choose Track > Show Master Track.
Choose Mix > Show Automation.
Choose Volume from the Automation menu in the master track header.
Add volume points to the beginning of the volume curve for a fade-in, or to the end of the curve for a fade-out.
Move the volume points to adjust the length and depth (intensity) of the fade-in or fade-out.
You can add other volume changes to the master track, and use it to control other functions, such as master effect settings. For more information about automating track parameters, see Show track automation curves in GarageBand on Mac and Add and edit automation points in GarageBand on Mac.