Apple Final Cut Express HD - Manual (Page 658)

658 Part VIII Audio Mixing
Edit in sound to handle a loud background noise at an edit point.
If you’re cutting from one clip to another, but there’s a loud sound right at the edit
point, such as a car or a plane passing, you can edit in sound to mask the cut. You won’t
be able to eliminate the noise, but if you take another car or plane sound effect that
sounds similar to the noise at your edit point, you can edit in just enough of the sound
effect in an adjacent audio track to complete the noise of the car or plane passing that
was cut off by your edit. You’ll need to play with the levels, mixing up the sound effect
prior to the edit point and mixing it down afterward, but you’ll be able to mask it so
that the cut sounds completely natural.
Swap onscreen sound effects with new ones using a replace edit.
If you want to replace the sound of a door slamming in your source audio track with a
more dramatic door-slam sound effect, you can easily and quickly line up the new
sound effect waveform with the old one by doing a replace edit, so that the new sound
is perfectly in sync.
Tips for Cutting Music
Use the natural beginnings and endings of music clips for your edits.
Instead of fading a piece of music in and out of a sequence at random points, try
matching specific parts of the music with parts of the video clips in the sequence for a
dramatic impact. Then, at the points where you need to start and end this music in
your sequence, edit in the beginning and the ending from that track, lining them up to
match the rhythm and melody of the part of the track that you’re using.
Using a music track’s natural beginning and end sounds much better than just cutting
into the middle of it, and you can usually create a series of edits using different pieces
of the same musical track to make it work.
Use subframe syncing to keep music on the beat.
Since music has a consistent rhythm, inconsistencies in the rhythm caused by edits to a
music track can be painfully obvious. Since one-frame increments are rarely detailed
enough to ensure perfect sync of rhythm in a track, use subframe syncing for each
segment that you edit to make sure the edit points between two clips from the same
song are in rhythm.