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Chapter 4 Dynamics 41
DeEsser
The DeEsser is a frequency-specific compressor, designed to compress only a particular
frequency band within a complex audio signal. It is used to eliminate hiss (also called
sibilance) from the signal. The advantage of using the DeEsser instead of an EQ effect
to cut high frequencies is that it compresses the signal dynamically rather than
statically. This prevents the sound from becoming darker when no sibilance is present
in the signal. The DeEsser features extremely fast attack and release times.
When using the DeEsser, you can set the frequency range being compressed (the
Suppressor frequency) independently of the frequency range being analyzed (the
Detector frequency). The two ranges appear separately in the DeEsser window for easy
comparison. The DeEsser performs gain reduction on the Suppressor frequency range
for as long as the threshold for the Detector frequency is exceeded.
The DeEsser does not use a frequency dividing network (a crossover utilizing low and
highpass filters). Rather, it is based on subtracting the isolated frequency band, and so
does not alter the phase curve.
DeEsser Parameters
The Detector parameters are on the left side of the DeEsser window, and the
Suppressor parameters are on the right. The center section includes the Detector and
Suppressor displays and the Smoothing slider.
Detector Section
 Detector Frequency knob: Sets the frequency range the DeEsser analyzes.
 Detector Sensitivity knob: Sets the degree of responsiveness to the input signal. At
higher ratios, the Detector reacts more responsively.
 Monitor pop-up menu: Choose whether to monitor the filtered Detector signal (Det.),
the filtered Suppressor signal (Sup.), or the sound removed from the input signal in
response to the Sensitivity parameter (Sens.). Choose Off to hear the DeEsser output.