Work with the master track
Each Logic Pro project has a master track. When you show the master track, it appears below the last track in the Tracks area. You can edit master volume automation on the master track, and edit automation for shared effects on its subtracks.
The master track is a Track Stack. For stereo projects, the main track is assigned to the stereo output chosen in Logic Pro > Preferences > Audio > I/O Assignments > Output, typically Output 1-2. For surround projects (with at least one channel strip routed to surround), the main track is assigned to the master channel strip, which carries the surround sum processing plug-ins. All shared effect aux channel strips (auxes using a Bus as input, which is fed via Sends) are automatically added as subtracks. All output tracks in the project, and all effect auxiliary tracks are affected by changes to the master track.
Neither the main track nor any of the subtracks of the master track contain audio or MIDI regions, but they may contain automation data.
Show the master track
Choose Track > Show Master Track from the Tracks area menu bar.
The master track appears below the last track in the Tracks area.
Edit the master volume automation curve
Show the master track in the Tracks area.
Choose View > Track Automation from the Tracks area menu bar.
In the master track header, choose Volume from the Automation pop-up menu for the main track.
Add and edit automation points on the master volume curve.
Show or hide the subtracks for the master track
Click the disclosure triangle to the left of the track icon in the main track.
After you show the subtracks for the master track, you can choose shared effect parameters to automate, record or add automation points, and edit the automation to control shared effect parameters.
You can set the basic playback volume using the Master Volume slider in the control bar. This slider corresponds to the master channel strip in the Mixer, and acts as a master volume control for the overall project. For more information, see Control the overall project volume.