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Chapter 4 Dynamics processors 87
DeEsser
DeEsser is a frequency-specic compressor, designed to compress 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 DeEsser rather than an EQ 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. DeEsser has extremely fast attack and release times.
When using 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 can be compared in DeEsser’s Detector and Suppressor frequency range displays. The
Suppressor frequency range is reduced in level for as long as the Detector frequency threshold
is exceeded.
DeEsser does not use a frequency-dividing network—a crossover utilizing lowpass and highpass
lters. Rather, it isolates and subtracts the frequency band, resulting in no alteration of the
phase curve.
The Detector parameters are on the left side of DeEsser’s interface, and the Suppressor
parameters are on the right. The center section includes the Detector and Suppressor displays
and the Smoothing slider.
DeEsser Detector parameters
•
Detector Frequency knob and eld: Rotate to set the frequency range for analysis.
•
Detector Sensitivity knob and eld: Rotate to set the degree of responsiveness to the
input signal.
•
Monitor pop-up menu: Choose the signal type that you want to monitor. Choose Det(ector)
to monitor the isolated Detector signal, Sup(pressor) to monitor the ltered Suppressor
signal, Sens(itivity) to remove the sound from the input signal in response to the Sensitivity
parameter, or O to hear the DeEsser output.
DeEsser Suppressor parameters
•
Suppressor Frequency knob and eld: Rotate to set the frequency band that is reduced when the
Detector sensitivity threshold is exceeded.
•
Strength knob and eld: Rotate to set the amount of gain reduction for signals that surround
the Suppressor frequency.
•
Activity LED: Indicates active suppression in real time.