ALCATECH BPM STUDIO 4 PRO User Manual page 45

AGC
AGC Presets
For quick deployment of AGC,
five pre defined parameter sets
are available. These are
adjusted situation specific.
Select a preset most suitable for
your need, and fine adjust it for
your purpose.
starts and stops the AGC
module
Mixer switches back to the
mixer audio channels.
Work method of the AGC
Following is a quick description of the work
method of AGC at different input levels. (See also
diagram on next page)
All shown values are standard values and can
be, depending on application, changed.
Up to point A the AGC does not take effect, since
the input level does not reach the threshold level
of –42dB.
From point A on, the AGC gets active, trying to
raise the output level to the target of –15dB since
scope is set to a value of 15dB, the signal can
only be amplified by 15dB.
From point B on, the input signal is less den 15dB
(Scope) smaller than the target, and the AGC is
now able to define the output level to accurately
–15dB. The volume difference between point B,
and point C will be balanced out, since in any
case the deviation is less than the 15dB scope.
From point C on the input signal is more than
15dB stronger. The AGC lowers the signal by
15dB.
Meanwhile the output signal exceeds the 10dB
limit set by the limiter, and will immediately cut
off. At point D then, the volume difference of input
signal to target is lower than the scope value,
and the AGC can level to the –15dB target again.
Between E and F, the amplification reaches it's
limit of 15dB again.
From point F on, the input level will again fall short
of the action range of the AGC, and the input
signal will again be routed to the output
unchanged.
In this diagram it is assumed that changes are
made without delay. If according values are
defined for attack and release, the controls trigger-
and fade behavior is delayed accordingly.