
114 Audio Effects: Theory, Implementation and Application
Stereo Phaser
Just as with stereo angers and chorus units, a stereo phaser can be created
from two monophonic phasers with different lter settings, creating notches
at different frequencies. Typically, the notches are controlled by two low-
frequency oscillators in quadrature phase, where the output of one oscillator
trails the other by 90°.
An optional addition is to selectively mix the outputs of each lter, which
can create additional notches (Figure4.10). The phaser effect can even be
created acoustically with no mixing at all: each feed- across gain is set to zero,
and each output ...