Advertisement
Before to proceed illustrating the editing and setting of the AGC parameters, it is good to remind
how an AGC (Automatic Gain Controller) is working
Referring to the following picture
The AGC is an Expansion/Compression process applied with pretty slow Attack and Release times
to the INPUT signal of a Unit, in order to maintain the average amplitude of the OUTPUT signal at
a defined level, independently from the averaged amplitude of the input sources.
For this purpose, the AGC has to be able to expand the input signal, there where the average of
the related output signal is below a defined Threshold (Exp Thr), and to maintain the expanded
signal at a constant expansion level when the averaged signal is beyond a defined Threshold (Thr
Hold).
The AGC implemented in the CLP2600 is acting on the evaluation of an input signal which is ana
averaged one on a 50ms time frame, and representing actually the RMS value of the input signal
itself, so to make more
Musical
the AGC action.
If the output signal of the AGC process will exceed then a defined Threshold (Cmp Thr), so
becoming too loud, a compression process is occurring.
The Speed and the amount of the Expansion can be defined through the
Exp Time' and
Exp
Ratio
parameters, so as the Speed and the amount of the Compression can be defined through
the
Cmp Time
and
Cmp Ratio
parameters.
When the Signal coming out from the AGC process (Output), applied to the AGC input, is above
Thr Hold , it is expanded up to the max expansion coefficient
the
Exp Thr
and below the
defined by the Exp Ratio.
23
Advertisement
