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User Manual
9.5.5 Dynamics
Dynamics is provided on each system Feed, with a Compressor/Limiter and Expander/Gate for each.
Access is from the Central Assignment Panel (CAP), which shows all parameters for the currently selected Feed.
Press the INT button on any fader to display it on the CAP.
The Compressor/Limiter and Expander/Gate each have an ON/OFF switch to activate them. The other controls are as
follows:
9.5.5.1
Compressor/Limiter
Threshold - sets the audio input level above which gain reduction will start to occur. The rotary control is labelled
from -40 dB to +10 dB, and this is referenced to -10 dBFS to provide headroom. This means that +10 on the rotary
control corresponds to 0 dBFS, the maximum level of the digital channel.
Ratio - shown as N:1 - for every N dBs by which the input audio exceeds the Threshold level, the output audio rises
by one dB. For example, if the Ratio is set to 3:1, the audio output from the compressor rises by one dB for every
three dB increase at its input.
Attack - the time taken by the compressor to activate after the audio exceeds Threshold. Setting the attack too fast
may result in objectionable artifacts due to the gain reduction aliasing into the audible spectrum.
Release - the time taken for the compressor to remove its gain reduction after the audio has dropped below Thresh-
old.
9.5.5.1
Expander/Gate
Threshold - sets the audio input level below which gain reduction will start to occur. The rotary control is labelled
from -40 dB to +10 dB, and this is referenced to -10 dBFS to provide headroom. This means that +10 on the rotary
control corresponds to 0 dBFS, the maximum level of the digital channel.
Range - the maximum amount of gain reduction produced by the Expander/Gate.
Gate ON/OFF - When the Gate is switched ON, the audio level is reduced by the entire amount of RANGE whenever
it drops below Threshold. When it is switched OFF, the Expander operates, and this drops the level by a ratio of 2:1.
Attack - the time taken by the Expander/Gate to activate after the audio drops below Threshold. Setting the attack too
fast may result in objectionable artifacts due to the gain reduction aliasing into the audible spectrum.
Release - the time taken for the Expander/Gate to remove its gain reduction after the audio has risen above Threshold.
Notes:
1.
The Expander/Gate and the Limiter/Compressor combine to produce a single transfer function. It is possible
to get quite eccentric transfer functions by having the Expander Threshold above that of the Compressor.
2.
In general the audio level drops when Dynamics are used. You can use the Makeup Ref control on the
Dynamics Page to compensate for this.
