Linear Acoustic LA-5100-DTV User Manual page 42

Linear Acoustic AERO.one User Guide
Parametric Eq(ualization)
Three bands of parametric equalization are provided for fine tuning if necessary. None of
the factory-supplied presets use the parametric equalizers, but they are provided to create
notch filters or other effects if necessary. Each filter has a gain control with a +/-12dB
range, a center frequency control that varies from 20 Hz to 22.050 kHz, and a bandwidth
or "Q" control that varies between 0 and 10. Normal default settings for all bands are Gain
= 0dB, in other words bypassed.
Input AGC
The input AGC is a very slow acting front-end gain control with a 36dB gain range whose
only purpose is to make sure that the following processing stages are fed with the correct
average audio levels. It is basically the automatic equivalent of an operator slowly riding a
gain control on a console to keep the audio close to reference level. Wideband in nature,
the AGC is not meant to perform rapid gain reduction or expansion as its actions will be
more audible, as with all wideband gain processors. As a slow gain rider, its actions are
nearly inaudible thanks to the multiband processing that follows it. The AGC has two stag-
es of gating where the gain expansion is slowed or stopped to prevent background noise
increasing.
Adjustable parameters are:
NOTE: Adjust Gate and Freeze to match plant practices. Very quiet audio (such as a
golf match) benefits from having processing frozen when input audio drops be-
low a given level to prevent "boosting the cricket" sounds.
• Gating Thresh(old): 0dBFS to -90 dBFS (default: -30dBFS)
-Gating sets the point at which the AGC release is made extremely slow to pre-
vent increasing background noise and allow the AGC to return to unity gain.
• Freeze Thresh(old): 0dBFS to -90dBFS (default: -42dBFS)
-Freeze stops all gain change (i.e. when the audio drops to silence), and remains
frozen at its current gain value until the threshold is exceeded.
• Ratio: 1:1 to Inf:1 (default: 12.0:1)
• Range: 0dB - 36 dB (default: 24dB)
-Range sets how much gain expansion above unity is performed, and this
amount is subtracted from the total AGC gain range of 36dB, so the default
value allows for 24dB of expansion and 12dB of compression. This adjustment
is reflected in real time by changing the AGC meter scale.
Presets, Processing & Metadata
36