PRESONUS STUDIOLIVE 16.4.2 - V1.12 User Manual page 103

5 Tutorials
5.3 A Brief Tutorial on Dynamics Processing
Types of Dynamics Processing
5.3.2
• A vocal performance usually has a wide dynamic range. Transients (normally the loudest
portions of the signal) can be far outside the average level of the vocal signal. Because
the level can change continuously and dramatically, it is extremely difficult to ride the level
with a console fader. A compressor/limiter automatically controls gain without altering the
subtleties of the performance.
• A solo guitar can seem to be masked by the rhythm guitars. Compression can make your
lead soar above the track without shoving the fader through the roof.
• Bass guitar can be difficult to record. A consistent level with good attack can be achieved
with proper compression. Your bass doesn't have to be washed out in the low end of the mix.
Let the compressor/limiter give your bass the punch it needs to drive the bottom of the mix.
Expansion
There are two basic types of expansion: dynamic and downward. Expansion increases the dynamic
range of a signal after the signal crosses the expansion threshold. Dynamic expansion is basically
the opposite of compression. In fact, broadcasters use dynamic expansion to "undo" compression
before transmitting the audio signal. This is commonly referred to as companding ' or COMPression
followed by expANDING .
By far the most common use of expansion is downward expansion . In contrast to compression,
which decreases the level of a signal after it rises above the compression threshold, expansion
decreases the level of a signal after the signal goes below the expansion threshold. The amount of
level reduction is determined by the expansion ratio. For example, a 2:1 expansion ratio reduces
the level of a signal by a factor of two. (e.g., if a level drops 5 dB below the expansion threshold,
the expander will reduce it to 10 dB below the threshold.)
Commonly used for noise reduction, expansion is very effective as a simple noise gate. The major
difference between expansion and noise gating is that expansion is dependent on the signal level
after the level crosses the threshold, whereas a noise gate works independent of a signal's level
beyond the threshold.
Noise Gating
Noise gating is the process of removing unwanted sounds from a signal by attenuating all signals
below a set threshold. As described above, the gate works independently of the audio signal after
being 'triggered' by the signal crossing the gate threshold. The gate will remain open as long as the
signal is above the threshold. How fast the gate opens to let the 'good' signal through is determined
by the attack time . How long the gate stays open after the signal has gone below the threshold is
determined by the hold time . How fast the gate closes is determined by the release . How much the
gate attenuates the unwanted signal while closed is determined by the range.
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