OPERATING INSTRUCTIONS FOR GAMBIT DE-ESSER/COMPRESSOR DS1-MK2
OPERATION
-
Weiss Engineering Ltd., Florastr. 42, CH-8610 Uster
Page 10 of 29
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Non-Linear Transfer Curve
The transfer curve parameter controllers are in
area
Ð
. This part of the sidechain is responsible
for the actual gain reduction (
²
) calculations. The
detected signal envelope is compared with the
transfer curve, the gain control signal (see Graphic
5) is then adjusted accordingly if the envelope
overshoots the transfer curve.
Threshold:
Sets the level which the envelope
signal has to reach before gain reduction is ap-
plied.
Ratio:
Sets the slope of the segment above the
threshold. The ratio can be adjusted for compres-
sion or expansion, depending on the requirement.
For full band expansion (e.g. to re-introduce
dynamics into an over-compressed signal), one
will usually work with the gain makeup set to
maximum. This means that a 0.0dB input will be
passed through without gain, signals below the
threshold will be reduced with a constant gain
(depending on threshold and ratio setting, can be
read from the display when touching the gain
makeup controller), and signals between the
threshold and 0.0dBFS get expanded. For full
band expansion, one will typically have quite high
thresholds (-1dB ... –4dB), because of the
resulting overall gain.
The expander can also be used in frequency
selective mode, for example to repair the effect of
a misused multi-band compressor – for this
purpose, the gain makeup can be set higher than
the calculated maximum setting, to compensate
for the overall gain that the expander causes. This
can potentially cause overs (for loud signals in the
expanded band), it is therefore good practice to
engage the safety limiter (see below).
The expander can only amplify gain differ-
ences. This means that it cannot create a
dynamic signal if there was no initial gain
difference (as is the case in computer gener-
ated music or with extremely hard-limited
mixes).
Soft-knee:
Determines how much the knee is
rounded. The maximum setting (1.0) chooses a
curve that reaches from 0dBFS down to twice the
threshold value. This implies that if soft-knee is
engaged the signal is already affected even if its
envelope lies below the threshold.
Gain makeup
Ñ
:
Moves the whole transfer
curve up or down. In de-essing mode the gain
makeup is usually set between the minimum (-
10dB gain) and "off" (0dB gain) to actually attenu-
ate the processed signal, while in compressor (full
band) mode the transfer curve usually gets to lie
anywhere between "off" and "max", according to
the amount of loudness correction one wants to
apply.
Once "max." is on, the transfer curve is attached
to 0dBFS for maximum possible gain. "max" is
engaged as soon as the curve reaches 0dBFS by
manipulating any combination of the above pa-
rameters, or by selecting "max" from the gain
makeup menu. This mode can be exited by manu-
ally reducing the gain makeup or by selecting "off"
from the gain makeup menu.
The applied gain reduction from the com-
pressor section is displayed in
²
²
.
Signal Meters:
The meters in
®
show the level
of the input (horizontally on top of the transfer
curve graph) and output of the compressor stage
(vertically to the right of the transfer curve). Refer
to Graphic 8 and Graphic 9 to see metering
points.
Graphic 7: Transfer Curve Parameters