Apple Final Cut Pro 6 - Manual (Page 864)

Chapter 4 Overview of the Audio Mixer 79
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When you first open the Audio Mixer, the default view is View 1, showing all audio
tracks in your sequence. Any tracks you show or hide using the Track Visibility controls
while the View 1 button is selected are remembered as View 1.
If you click the View 2 button and then show or hide audio track strips, that altered
layout is remembered as View 2.
Clicking the View 1 button restores the state of the Audio Mixer to View 1, the way it
was before you clicked the View 2 button.
View 1 showing only the
first four audio track
strips
View 2 showing only the
last three audio track
strips