Dialogue Editing

Reducing Ambient Noises 227
Figure 12-14 A spreadsheet for logging harmonics and calculating the Q. If the
frequency pattern is predictable, you can use a spreadsheet to predict the higher
harmonics.
Figure 12-15 Once you determine the center frequency, gain, and Q for the
principal harmonics, you can use a multiband EQ to remove the harmonic noise.
In this case, a Waves Q10 is set to the parameters shown in the spreadsheet in
Figure 12-14.
Broadband Noise Removal Many manufacturers sell broadband noise
reduction processors. Perhaps because they require relatively little user interaction,
or maybe because they’re very sexy, they’re best-sellers. The key to
using them successfully is understanding what they do and don’t do.
Broadband noise reduction devices work by fi rst taking a sample of “pure
noise,” ideally from a pause free of any valid signal. This serves as the blueprint
of what’s wrong with the sound. Next they move the noise sample and
signal from the time domain to the frequency domain by creating ever