Technical data

DOC-01-TELAS-CRG-4 ASTi ACE Studio Components Reference Guide Rev.M
14 Copyright © 2014 Advanced Simulation Technology inc.
2.5. Compressor
Summary: This component includes a gate, expander, compressor, and limiter
module. The Compressor component modifies the dynamic range of an audio
signal to provide a form of automatic volume control.
Description: The gate module acts to ensure that there is no audio signal below a
certain threshold level. Once the signal level falls below the specified threshold, the
gate will close after the hold time has passed and will output a signal with a gain of
0.
The expander module makes quiet sounds quieter. That is, if a signal is under the
expander threshold, its gain is reduced by the specified ratio. Lower ratios produce
more aggressive gain reductions.
The compressor module makes loud sounds quieter. If a signal rises above the
compressor threshold the compressor will start to reduce the gain on that signal.
The higher the ratio value is, the more aggressive this gain reduction will be.
The limiter module acts like a compressor with an infinite ratio and instant attack so
that the output signal is a scaled version of the input signal with the highest peak
level reaching the threshold.
Figure 1: Compressor Process
Figure 2: Compressor Static Curve
Side
In
Compressor
Limiter
Expander
Gate
Side
In
Out
Side
In
Out
Side
In
Out
Output
Prevents low level audio from passing
Reduces the gain if below a certain threshold
Reduces the gain if above a certain threshold
Scales the output signal based on the input
signal’s threshold