User Manual

WAVELAB
Editing in the Wave window 6 – 95
Snapping to zero crossings
About zero crossings
If you cut out a portion of a wave and paste it in somewhere else, chances
are there will be a discontinuity where the two waves are joined. See the
example below. This discontinuity will result in a transient in the wave when
it is played back, which is perceived as a “click” or “bump” in the sound.
To avoid this you need to make the splice at a zero crossing.
A zero crossing is – a point where the wave crosses the zero level axis,
the point where the wave is considered to have “zero level”.
Furthermore we recommend that joins are made with the splice points of
the two waves heading from opposite directions to the zero crossing.
That is, one should be on its way up (below the zero level axis), and the
other should be on its way down (above the zero level axis).
WaveLab can help!
If you wish, WaveLab can automatically search for zero crossings, and ex-
tend the selection “outwards” (make it bigger at both ends) so that it begins
and ends at a zero crossing. Normally this will not be noted in the editing
precision (since there are usually hundreds or thousands of zero crossings
per second), but it will help avoid “clicks” and “pops” and “bumps”.
But just making the selection start and end at zero crossings is not enough.
When you actually perform the editing operation (cut and paste or drag-
ging, for example) you need to make sure the material is inserted at a zero
crossing. See “By dragging” on page 99.
At this point, there will be a
click in the sound, due to the
discontinuity in the splice.