Operator Manual

252 Chapter 30: Input Channels
PRO2 Live Audio System
Owner’s Manual
About the compressor graph
The GUI shows a graph of the compressor envelope (input
level against the output level) to help you visualise the effect
that the compressor is having on the signal (typically as shown
right).
Figure 23 “Compressor graphs showing the effect of ratio”
shows what happens to the compressor graph with and
without ratio. Initially, both graphs have the same slope,
which is pre-threshold and unaffected by compression; this
has a gradient of 1:1 — ‘what you put into the compressor,
you get out’. Without ratio the slope is constant and remains
unaffected by compression. However, with ratio the gradient changes at threshold,
which is the point where compression starts to be applied. After this the gradient of the
post-threshold signal is at the selected ratio value.
Figure 23: Compressor graphs showing the effect of ratio
The diagram right shows the effects of
threshold adjustment. Position 2 is the
threshold of the actual compressor graph
shown on the GUI. If you reduce threshold
(for example, to position 1), compression
starts earlier and less signal is passed 1:1;
the signal path would follow the green line.
Conversely, increasing threshold (for
example, to position 3) delays compression
and more signal is passed 1:1; the signal
path would follow the yellow line.
Input level
Output level
With ratio appliedNo ratio applied
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