Vocabulary Of Dynamics Processors - PRESONUS STUDIOLIVE 16.4.2 - V1.12 User Manual

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5.3 A Brief Tutorial on Dynamics Processing

Vocabulary of Dynamics Processors

5.3.3
In scientific research, it is widely accepted that if one needs to master a subject quickly, one
must learn the associated vocabulary and industry terms. The same is true with audio recording
and production. Most manuals and text books assume a prior level of knowledge. We hope this
section will help you to get the greatest benefit from your independent study in the world of music
production.
Compressors
• Threshold. The compressor threshold sets the level at which compression begins. When the
signal is above the threshold setting, it becomes eligible for compression. Basically, as you
turn the threshold knob counterclockwise, more of the input signal becomes compressed
(assuming you have a ratio setting greater than 1:1).
• Ratio. Ratio sets the compression slope. The ratio is the relationship between the output
level and the input level. In other words, the ratio sets the compression slope. For example, if
you have the ratio set to 2:1, any signal levels above the threshold setting will be compressed
at a compression ratio of 2:1. This simply means that for every 1 dB of level increase into
the compressor, the output will only increase 0.5 dB, thus producing a compression gain
reduction of 0.5 dB/dB. As you increase the ratio, the compressor gradually becomes a
limiter.
• Limiter. A limiter is a compressor that is set to prevent any increase in the level of a signal
above the threshold. For example, if you have the threshold knob set at 0 dB, and the ratio
turned fully clockwise, the compressor becomes a limiter at 0 dB, so that the output signal
cannot exceed 0 dB regardless of the level of the input signal.
• Attack. Attack sets the speed at which the compressor acts on the input signal. A slow attack
time (fully clockwise) allows the beginning envelope of a signal (commonly referred to as the
initial transient ) to pass through the compressor unprocessed, whereas a fast attack time
(fully counterclockwise) immediately subjects the signal to the ratio and threshold settings
of the compressor.
• Release. Release sets the length of time the compressor takes to return the gain reduction
back to zero (no gain reduction) after the signal level drops below the compression
threshold. Very short release times can produce a very choppy or "jittery" sound, especially
in low-frequency instruments such as bass guitar. Very long release times can result in an
overcompressed sound; this is sometimes referred to as "squashing" the sound. All ranges
of release can be useful at different times, however, and you should experiment to become
familiar with the different sonic possibilities.
• Hard/Soft Knee. With hard-knee compression, the gain reduction applied to the signal occurs
as soon as the signal exceeds the level set by the threshold. With soft-knee compression,
the onset of gain reduction occurs gradually after the signal has exceeded the threshold,
producing a more musical response (to some folks).
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