Soundtrack Pro 3 Effects Reference (en).pdf - Help Library - Apple

Using SubBass
Unlike a pitch shifter, the waveform of the signal generated by SubBass is not based on
the waveform of the input signal, but is sinusoidal—that is, it uses a sine wave. Given
that pure sine waves rarely sit well in complex arrangements, you can control the amount
of—and balance between—the generated and original signals with the Wet and Dry
sliders.
Use the High and Low parameters to define the two frequency bands, which SubBass
uses to generate tones. High Center and Low Center define the center frequency of each
band, and High Bandwidth and Low Bandwidth define the width of each frequency band.
The High Ratio and Low Ratio knobs define the transposition amount for the generated
signal in each band. This is expressed as a ratio of the original signal. For example, Ratio
= 2 transposes the signal down one octave.
Important: Within each frequency band, the filtered signal should have a reasonably
stable pitch in order to be analyzed correctly.
In general, narrow bandwidths produce the best results, because they avoid unwanted
intermodulations. Set High Center a fifth higher than Low Center, which means a factor
of 1.5 for the center frequency. Derive the sub-bass to be synthesized from the existing
bass portion of the signal, and transpose by one octave in both bands (Ratio = 2). Do not
overdrive the process or you will introduce distortion. If you hear frequency gaps, move
one or both Center frequency knobs, or widen the Bandwidth of one or both frequency
ranges a little.
Tip: Be prudent when using SubBass, and compare the extreme low frequency content
of your mixes with other productions. It is very easy to go overboard with it.
160 Chapter 12 Specialized Effects and Utilities