Instruments and Effects

Chapter 4 Dynamics 65
Other Parameters
Because the Compressor works by reducing levels, the overall volume of its output is
typically lower than the input signal. You can adjust the output level using the Gain
slider.
You can use the Auto Gain parameter to compensate for the reduction in gain
produced by compression, referenced to either –12 dB or 0 dB. Auto Gain sets the level
of gain (amplification) to a value of T—(T/R), where T = the Threshold and R = the
Ratio.
The Gain Reduction Meter displays the amount of compression occurring as the signal
plays. It’s useful to watch how much your tracks are being compressed, and to make
sure they’re not being overly compressed.
When using the Platinum Circuit Type, the Compressor can analyze the signal using
one of two methods: Peak or RMS (root mean square). While Peak is more technically
accurate, RMS provides a better indication of how people perceive the signal’s
loudness. When using the Compressor primarily as a limiter, select the Peak button.
When compressing individual tracks, especially music tracks, select the RMS button.
If you activate Auto Gain and RMS simultaneously, the signal may be saturated. If you
hear any distortion, switch Auto Gain off and adjust the Gain slider until the distortion
is gone.
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.