Extron electronics DMP 128 User Manual page 52

AGC (Automatic Gain Control)
AGC adjusts the gain level of a signal based on the input strength to achieve a more
consistent volume. Below the set threshold, the signal is not affected. Above the threshold,
weaker signals are boosted up to the maximum gain setting to reach a user-defined target
level. As the signal level approaches the target level it receives less gain or no gain at all.
Once the signal level reaches the target level all gain is removed. Click in each field or use
the sliders to change the values.
Threshold — The input level where maximum
gain is applied (after the attack time is exceeded).
On the graph at right follow the red input level
from the lower left to -40 dB where the first red
circle is. Signal levels less than -40 dB remain at
their original levels. Signal levels at or exceeding
-40 dB have up to 12 dB of gain applied
(Maximum Gain).
The threshold level can be adjusted from -80.0 to
0.0 dB in 0.1 dB increments.
Default is -40.0 dB.
Maximum Gain — The highest amplification
applied to a signal exceeding the threshold and
up to the lower limit of the window (see Window
below).
Maximum Gain can be set from 0.0 dB to +60 dB
in 0.1 dB increments.
Default is 12.0 dB.
Target — The desired average signal level of the
output when AGC is applied. AGC can vary the
gain according to the input signal level, specified
target level and maximum gain. As the signal
approaches the target level of – 10 dB, gain is
reduced until at – 10 dB, gain is no longer applied.
The target level can be adjusted from -40 dB to
0.0 dB in 0.1 dB increments.
Default is – 10.0 dB.
Window — Indicated by two yellow lines, is a specified range above and below the target
level. Below the lower line maximum gain is always applied to the signal. When the signal
reaches the window, gain control begins scaling in a linear fashion to achieve smoother
results as the signal reaches the target level.
The window range can be set in 0.1 dB increments from 0.0 dB to 20.0 dB.
The default threshold is – 40 dB. The default target level is – 10.0 dB. The default window
range is 12.0 dB.
Attack Time — Adjusts the time delay for AGC to engage after the input signal level
reaches or exceeds the threshold level.
Attack time can be adjusted from 0.0 to 3000.0 ms in 0.1 ms increments.
Default is 500.0 ms.
Hold Time — Adjusts how long AGC continues to boost the signal after the input signal
drops below the threshold and before release time begins.
Hold time can be adjusted from 0.0 to 3000.0 ms in 0.1 ms increments.
Default is 0.0 ms.
Release Time — Adjusts the time it takes to return the signal to normal (unprocessed)
levels after the signal no longer exceeds the threshold level setting. Release time begins only
after hold time is reached.
Release time can be adjusted from 10.0 to 10000.0 ms in 0.1 ms increments.
Default is 1500.0 ms.
DMP 128 • Software Control 46