soundtrack pro

Sound envelopes allow you to manipulate the audio levels at different points in an audio track, such as creating a fade in or a fade out in an audio clip.

You have to be in the multitrack view to manipulate sound envelopes.

To display a sound envelope, look to the far left of an audio track for the name of the track. Next to the track name you'll see a tiny triangle.

Click on the tiny triangle next to the track icon and the Sound Envelope will appear under the audio track.

The Sound Envelope has two purple tracks.

One is for adjusting Volume, the other is for adjusting Panning.

In the volume envelope, the horizontal black line that runs through the middle of the track represents the audio level for that track.

If, at the very beginning of the track, you click on the triangle at the start of the horizontal line, you'll be able to use the triangle to move the volume up or down for all the audio on that track.

If you want to increase or decrease the volume only in certain parts of a clip, move the cursor along the volume line to the point where you want to change the volume. Double click on that point.

A tiny diamond should appear on the black horizontal line.

Move to the next point where you want to change the volume and double click again. Another tiny diamond will appear.

Now click once on one of the diamonds and drag it up or down to adjust the audio volume.

Use the same procedure to create more diamonds to adjust the volume up or down in other portions of the clip.

To remove one of the diamonds, click on it once and press the delete key on your keyboard.

Use the same procedure to adjust the Panning, by creating triangles on the horizontal line to move the audio up or down and shift the volume to the left or right channels.