The Compressor is Automatic Gain reduction device and it is one of the most valuable audio engineering tool. For me, it is the most needed and useful in today’s music. The compressor will attenuate the input signal that will overshoot the pre-designated volume level. Depending on the design of the compressor, it can increase the level of softer signals, reduce the louder signal or both. However, the end result will be reducing the ratio between the loud and soft parts.
The purpose for using compression is not to take out any volume difference, but to allow dips and rise in controlled range. The early compressors ware known as Leveling Amplifiers.
Some instruments are louder in their upper registers than in their lower ones. Compressors can reduce this difference to obtain a more uniform level.
For example, vocalists who wander away from their microphone, or portions of songs
with intense peaks, the bass guitar is usually a good candidate for compression since it
is renowned for often having one string louder than the others. Guitarists
kicking in a stomp box or a drummer’s over-enthusiastic snare beat are
easily corrected with the proper usage of the compressor.
Compression should be used to make a visible difference on the compressor’s meter, but not so much that the sound is audibly colored. Excessive compression can result in a squeezed or unpleasantly thin sound, on this particular compressor, the threshold is set by the amount of input signal
and can also increase any undesirable noise elements which are present in a signal.
As a general rule, each dB of compression brings about an equal amount of deterioration
in the signal-to-noise ratio of the input signal.
Compression is one of the most used techniques in recording, mixing and mastering. Learn how, when, and how much to use compressor in your projects. Using it with no proper basic knowledge will destroy the quality of your sound.