Apple Final Cut Pro 7 - Manual (Page 882)

Note: The meters in the Audio Mixer can actually display levels above 0 dBFS because
Final Cut Pro mixes audio internally at 32-bit floating-point resolution—much higher
than the 16- or 24-bit audio in typical media files. The high mixing resolution provides
enormous headroom to prevent clipping when multiple audio tracks are mixed together.
However, you should never output a signal that exceeds 0 dBFS on the Master audio
meters.
Acceptable range
Clipping range
Acceptable range
Master Area
Using the controls in the Master area, you can mute, downmix, and adjust the audio levels
of all audio tracks at once. The controls in the Master area cannot be automated, but the
current state of all controls in the Master area is stored in each clip in your project.
To show or hide the Master area
µ
Click the disclosure triangle in the upper-right corner of the Audio Mixer tab.
Master mute button
Master audio meters
Clipping indicators
Downmix control
Master fader
882 Chapter 55 Overview of the Audio Mixer