The Compressor effect reduces the dynamic
range of audio.
One of the main purposes of reducing dynamic range
is to permit the audio to be amplified further
(without clipping) than would be otherwise possible.
Therefore by default the Compressor amplifies audio
as much as possible after compression.
Equipment use :
• Software : Audacity 2.0.3 (free)
• Behringer mixer Q 1202 usb
The resultant increase in
average or RMS level can
be useful for audio played
in a noisy environment
such as in a car, or in
speech, to make a distant
voice sound as loud as a
close one. Because the
gain changes relatively
slowly, a compressor does
not distort the signal in the
way that a Limiter or
clipping would do.
The level above which compression is applied to the audio
and in audacity there is Noise Floor is The compressor adjusts
the gain on audio below this background level so as to prevent
it being unduly amplified in processing. This is mainly useful
when compressing speech, to prevent the gain increasing
during pauses and so over-amplifying the background noise
The amount of compression applied to the
audio once it passes the threshold level. The
higher the Ratio the more the loud parts of the
audio will be compressed. The Ratio sets the
slope of the blue line on the graph above the
Tips : 2:1 setting good for most recording
How soon the compressor starts to compress the dynamics
after the threshold is exceeded. If volume changes are slow,
you can push this to a high value. Short attack times will result
in a fast response to sudden, loud sounds, but will make the
changes in volume much more obvious to listeners.
Tips : 0.2 is just fast enough for voice recordings
How soon the compressor starts to release the
volume level back to normal after the level
drops below the threshold. A long time value
will tend to lose quiet sounds that come after
loud ones, but will avoid the volume being
raised too much during short quiet sections like
pauses in speech.
• Apply Gain after compressing option checked.
This will increase the overall volume of your
recordings slightly and, in many cases, help
alleviate any sound drop outs.
Before compression After compresion
Behringer Q 1202 usb
Compression limits the dynamic range of a
signal, lowering the level of loud sounds and
turning up softer sounds to achieve sonic
balance. But applying compression is a delicate
art that many novice, and even intermediate
sound techs have difficulty mastering
Using the COMP knop to adjust the amount of
compression effect on the channel this will limits
the dynamic range of the audio source