The Technical Stuff
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Attack and Release
The main key to the sonic imprint of any compressor lies in its
attack
and
release
times; these are the
parameters which most affect how “tight” or how “open” the sound will be after compression. The
attack time describes the amount of time it takes the compressor circuitry to react to and reduce the
gain of the incoming signal, usually given in thousandths of a second (milliseconds). The 2-LA-2
attack time is approximately 10 milliseconds (though, like ratio, this is somewhat program
dependent). A fast attack such as this kicks in almost immediately and catches transient signals of
very brief duration (such as the beater hit of a kick drum or the pluck of a string), reducing their level
and thus “softening” the sound. A slow attack time allows transients to pass through unscathed
before compression begins on the rest of the signal.
The release time is the time it takes for the signal to then return to its initial (pre-compressed) level. If
the release time is too short, “pumping” and “breathing” artifacts can occur, due to the rapid rise of
background noise as the gain is restored. If the release time is too long, however, a loud section of the
program may cause gain reduction that persists through a soft section, making the soft section
inaudible. The 2-LA-2 is unique in that it provides a dual stage release time: in the first 60
milliseconds, approximately half the signal is released, with the remainder taking anywhere from 1
second to 15 seconds to die away, depending upon its frequency content.
Makeup Gain
Finally, an output control is employed to make up for the gain reduction applied by the gain reduction
circuitry; on the 2-LA-2, this is the function of each channel’s Gain knob. Makeup gain is generally set
so that the compressed signal is raised to the point at which it matches the level of the unprocessed
input signal (for example, if a signal is being reduced in level by approximately -6 dB, the output
makeup gain should be set to +6 dB).
As you are adjusting a compressor, a switchable meter such as the one provided by each channel of
the 2-LA-2 can be helpful in order to view the strength of the outgoing signal (displayed when the
meter is set to OUTPUT) or the difference in levels between the uncompressed input signal and the
compressed output signal (displayed when the meter is set to GR). When in GR mode, the 2-LA-2 meter
will read 0 dB when there is no incoming signal or when no compression is being applied.
