Waves Linear-Phase MultiBand Software Audio Processor - Manual (Page 17)

Waves LinMB software guide page 17 of 28
Upper line shows Low-level compression (upward), achieved when Range is
negative and Gain is equal but positive. Lower line shows Low-level
expansion (downward), achieved when Range is positive and Gain is equal
but negative. Graph is taken from C1 to help visualize the gain structures in
the LinMB.
L
OW
-
LEVEL EXPANSION
(
NOISE GATE
)
If you are interested in a noise gate for a particular band or bands, set Range
to a positive Value, Gain to the inverse of the Range, and Threshold to a low
value (say -60dB). Similar to the above example, at high levels the full
dynamic gain increase set by the Range is retained, and is fully compensated
for by the Gain. While around and below the Threshold, the dynamically
changing gain comes closer to 0dB, and the result is that the fixed negative
Gain is applied to the low level signal — which is also known as gating (or
downward expansion).
“U
PSIDE DOWN
”
THINKING
These low-level examples may seem a little inverted to what you would
expect. For instance, that a noise gate would have a positive
Range.
If you just remember that when the signal goes around the Threshold, then
the Range becomes “active”, and that the Threshold is the halfway point of
the Range. So whether Range is +12dB or –12dB, then audio 6dB above and
6dB below the Threshold is where the “knees” of the dynamic change will
occur.
Positive Range
Then, if Range is positive and Gain is set to be the negative of Range
(opposite but equal), then around and above the Threshold all audio will be a
0dB gain (unity). Below the Threshold, the Range is not active, so the Gain
(which is negative) “takes over” and reduces that band’s gain. This is what
gives the downward expansion.
Negative Range
Another seeming example of the “upside down” concept is that low-level
compression takes a negative
Range. Again, remember that in the LINMB,
whenever the audio is around the Threshold, the Range is active. So, if we set
Range to negative, anything around or above the Threshold can be reduced
in gain. However! Here’s the tricky part: if we set Gain to perfectly offset the
Range value, then everything well above the Threshold has no effective gain