LA Audio MPX10 - Manual (Page 23)

Page 23
And the RATIO setting of 2:1 ratio means that for every 2dB the input signal
increases above the Threshold, the output will increase by only 1dB.
By enabling low level signals to be increased without a corresponding
increase in the high level signals, a compressor is able to increase the
average sound level without risk of high level distortion. This fundamental
principle of compression can be used for many applications.
Preventing tape and digital overload
Analogue tape is quite tolerant to overloading, producing its own tape
compression effect. However sending too much level to tape will result in
tape saturation distortion and track bleeding. This can be effectively
controlled with the MPX10.
Use the MPX10s compressor with a RATIO setting of 10:1 or higher and
THRESHOLD set to produce compression just below clipping.
Digital recorders, although handling a much wider dynamic range, are
highly intolerant to excessive levels and produce unpleasant distortion
when overdriven.
Use a RATIO of 20:1 and THRESHOLD set to reduce signal levels just
before the recorder reaches clipping. Start with AUTO set to fast mode.
Signal levelling
Signal level variations can occur when the distance between the vocalist
and microphone changes. The MPX10 compressor can be used to level
out the result of poor microphone technique, producing an even sound.
Set RATIO to around 4:1 and adjust THRESHOLD for a gain reduction of 6
to 10 dBs at maximum signal level.
N.B. If vocals sound thin after being compressed as described, use an
external Hi pass filter, patched into the Sidechain insert, set to reduce the
sensitivity of the compressor to low frequencies. This allows more low
frequency signals to pass unaffected and fattens the sound.
This technique can also be used to reduce level variations in bass, lead
guitars, and horns.
Bringing sounds forward in the mix
The use of a compressor to reduce the dynamic range of a sound source
increases the average level of the sound. This principle can be used to
accentuate a vocal or other lead track in a multitrack recording.
Use a gentle RATIO of around 2:1 and a THRESHOLD of approximately -
20dB to achieve gain reduction of no more than 6dB. Restore the
compressed signal to its original level using the GAIN control.