8
S
Se
ettttiin
ng
g tth
he
e C
Co
on
nttrro
ollss
If you are starting from scratch or have something out of whack and do not know exactly what to adjust‚
begin by setting the controls so that all functions are disabled. Here are the control positions for this:
E
Exxp
pa
an
nd
de
err
Threshold
Ratio
C
Co
om
mp
prre
esssso
orr
Threshold
Ratio
Attack
Release
Limit
Gain
Low Cut
De-ess
min (off )
min (1:1)
max (+20 dB)
min (1:1)
center (50 mSec)
center (.5 sec)
max (off )
min (0 dB)
out (off )
out (off )
Naturally‚ the controls that need to be adjusted depend on what you want to accomplish. Below are some
suggestions to get you up and running. Follow the order listed and leave the controls in the disabled
positions if that particular function is not required.
1. Determine the maximum output level and adjust the LLiim
miitt T
Th
hrre
essh
ho
olld
d so that‚ at the loudest
peaks‚ the output level never exceeds this point. (The action of the limiter can be seen on the
G
Ga
aiin
n R
Re
ed
du
uccttiio
on
n M
Me
ette
err. If it never activates‚ there will be no LED activity.) One way to do this is
to deliberately increase the input to the compressor until the desired maximum level is
exceeded‚ then turn the LLiim
miitt T
Th
hrre
essh
ho
olld
d control counter-clockwise until it limits it to the correct
gain. Reset the input level to the nominal setting (0 dBu average). An alternate method is to
turn down the LLiim
miitt T
Th
hrre
essh
ho
olld
d until gain reduction has just occurred. Then‚ adjust the output
level control to set the desired output level. If the limit is set too low‚ the signal will lose its
dynamic range and the sound will be squashed.
2. To set up a noise gate‚ first turn the E
Exxp
pa
an
nd
de
err R
Ra
attiio
o control fully clockwise (1:5). During quiet
passages of the source (between songs‚ when the mics are not being used‚ etc.) adjust the
E
Exxp
pa
an
nd
de
err T
Th
hrre
essh
ho
olld
d clockwise until gain reduction is indicated (a reduction of -9 dB is a good
starting point). Re-adjust the E
Exxp
pa
an
nd
de
err R
Ra
attiio
o to set the desired gating action when the source
changes from noise to signal. A setting of 1:1.2 has little action and can tolerate higher
threshold settings without coloring the sound; 1:5 will cause an abrupt turn on and off when
the signal changes and will probably need a lower threshold setting to prevent the signal from
dropping off when you don’t want it to. You may need to go back and adjust the threshold after
the ratio has been changed since the soft-knee circuitry has more affect at lower ratios‚ making
the transition point less obvious.
3. For typical voice compression‚ set the C
Co
om
mp
prre
esssso
orr R
Ra
attiio
o control to 4:1 (a range of 2:1 to 6:1 is
common) and adjust the C
Co
om
mp
prre
esssso
orr T
Th
hrre
essh
ho
olld
d until the desired amount of gain reduction is
seen on the meter. This is a personal preference but continuous gain reduction greater than -9
dB (especially with higher ratios) could be excessive and create pumping/breathing artifacts as
the signal rises and falls. Lower ratios will have a more gentle affect. Adjust the A
Atttta
acck
k control
to low values to suppress leading-edge spikes or to high values to let them through (often used
to pass through the click of a drum hit). The R
Re
elle
ea
asse
e control is adjusted to smooth the
transition as it comes out of compression. Too quick a release will cause the signal to sound
artificial. A fast attack and a short release time will cause the compressor to track the signal
very closely (and keep the dynamic range very limited)‚ but can severely impact the sound. (A
50 millisecond attack and a .5 second release time are good starting points.)
