LA Audio BCL20 - Manual (Page 9)

8
POWER POWER
(On rear panel)
This switches the unit ON or OFF and the adjacent led lights
when the unit is ON
5 APPLICATIONS 5 APPLICATIONS
DEFINITIONS OF TERMS USED DEFINITIONS OF TERMS USED
Compressor :
Compressor :
A variable gain amplifier whose gain decreases as the input
increases beyond a threshold point. A compressor uses ratios of
up to 8:1
Limiter : Limiter :
A limiter is a compressor with very high compression ratios,
usually above 10:1. A high ratio maintains an almost constant
output level despite large changes in the input level above the
threshold point.
Compression ratio : Compression ratio :
The ratio in dB of input level change to output level change
above the threshold point. A 4:1 compression ratio implies that
the output level will only change by 1dB for every 4dB that the
input level changes above the threshold point.
Threshold : Threshold :
This is the point at which compression starts to be applied as
the signal rises, or starts to be removed as the signal falls. The
Gain Reduction display will indicate when compression
commences, and then the threshold can be varied to obtain the
desired effect. Reducing the threshold point will give more
compression effect than leaving it just below the input level.
Peak detection : Peak detection :
It is closely related to the maximum electric amplitude of the
signal.
This characteristic is ideal for compressor-limiters used in
protection of transmission lines, amplifiers, broadcast
transmitters etc...
RMS Detection : RMS Detection :
It is related to the psycho-acoustic perceived "loudness". This
characteristic is more suitable for "creative" applications such as
drums fattening, bass sustain, vocal processing, etc...
De-essing : De-essing :
Reducing or removing the sibilance effect produced by some
microphones, some people, and certain sound sources. This is
achieved by making a compressor "frequency conscious". This
means that a pre-emphasis filter is placed in the side-chain,
which controls the compressor, making it work harder upon
those particular frequencies. In true de-ess mode, the