Soundtrack your iPhone movies

Use iMovie's suite of audio-enhancing tools to add slick soundtracks

- George Cairns

In the first two parts of our iMovie series, we explained how to create slickly edited video sequences complete with titles, transitions and layered picture-in-picture effects.

However, compelling visuals are only half of the movie story; sound is the other. Often, poor-quality sound lets the side down, with levels that are either too loud or quiet, or drowned out by music and unwanted background noises such as traffic.

In this tutorial, we'll explain how you can use iMovie's audio editing tools on Mac to give your audio tracks a post-production polish, adjusting volume to make quiet bits sound louder while reducing distorting peaks.

You'll also learn how to unify multiple clips by adding a music soundtrack that automatically dips in volume when people speak. We'll show you how to layer multiple audio tracks, such as voiceover and music, and sync sound effects so that they match onscreen events with precision.

HOW TO Adjust the volume

Enlarge the waveform

Click Settings. Drag the Clip Size slider right to enlarge the blue audio channel below the clip. This gives you a clearer view of the audio waveform displaying your clips' sound levels. Make sure the Show Waveforms checkbox is selected.