Section B.10. Problems with Sound

B.10. Problems with Sound

Sound problems are especially frustrating when you're working with digital video, because they bear no resemblance to sound problems with more familiar equipment. In any other situation, if sound is too low or too loud, for example, you can adjust it with a knob. But what you do about random electronic beeps and buzzes that weren't there on the original tape?

B.10.1. Sound Is Too Soft

If one particular clip is too soft, see page 227.

If, however, the entire movie soundtrack plays back too quietly , it's probable that iMovie has nothing to do with the problem. Instead, your overall Mac volume is probably too low. Visit the Sound panel of System Preferences and adjust the output volume of your machine, or tap the Volume Up key on the top row of your keyboard. Make sure that iMovie's own volume slider (just above the Movie Track) is up all the way, too.

B.10.2. Random Electronic Beeps

It's hard to imagine anything more frustrating than finding a permanentor, worse , intermittentbuzzing, crackling, or popping in the audio tracks of your project.

This problem has been on many minds, and its victims have come up with various solutions. Fortunately, most people manage to solve it by following one of these steps:

• Just as there are video dropouts, as described in the beginning of this appendix, cheap tapes may sometimes give you audio dropouts. The problem is exactly the same: a tiny bit of dirt or a nonmagnetized particle on the tape. But this time, it affects the audio, not the video. Try cleaning the heads of your camcorder, and then reimport the video.

• If cleaning the heads doesn't solve the problem, consider turning off the Audio Filtering feature. To do so, choose iMovie Preferences. Turn off "Filter audio from camera." Click OK.

  Again, try reimporting the video to see whether the sound-buzzing problems have disappeared.

Of course, these workarounds assume that the audio glitch began life on the camera, rather than within iMovie itself.

If the pop is intermittent, there's not much you can do. But if you hear the pop in the same place every time you play your movie, you may be able to repair it using a sound-editing program, like this:

1. Export the audio of the video clip as a sound-only AIFF file.

   That is, turn on only the relevant audio-track checkboxes (at the right end of the Timeline Viewer). Then Choose File Share. In the Share dialog box, choose the Expert Settings option, and then click Export. In the following dialog box, use the pop-up menu to choose Sound as AIFF.

   The result: You've just exported the soundtrack of your movie as a standalone audio file.

2. Using GarageBand, cut out the beeps.

   GarageBand lets you highlight the specific sound waves that represent the beeps and change their volume, or replace them with pieces of sound you've copied from neighboring moments in the soundtrack.

3. Reimport the AIFF sound file into your iMovie project.

   For example, choose File Export to iTunes, and then, in iMovie, use the Audio panel to import that "track from iTunes.

   Once it has appeared on an audio track, you can turn off the existing camcorder audio track.

B.10.3. Pops at Transition or Scene Breaks

Audio pops or snaps sometimes materialize where clips intersectthat is, at transitions and scene breaks. Fortunately, these audio defects don't survive to any DVDs you may burn.

If a DVD isn't the final destination for your project, the workaround is slightly more involved. First, remove the transition or title as described in Chapters 6 and 7.

Next, select the video clip that will be affected. Finally, choose Advanced Extract Audio.

iMovie HD places the audio from that video clip into one of its two audio tracks. If you apply the title or transition now, iMovie HD will leave the audionow an independent entityalone.