Omnia .9 Installation And Operation Manual page 49

The Input AGC is the first gain control stage in Omnia.9 following Undo, and is designed to be used
as a slower-­‐acting leveler ahead of the Wideband AGC1 and multiband compressor sections that
follow i t.
It i s w orth n oting t hat t raditional p rocessors o nly a ct u pon a udio a bove a p articular t hreshold. T hey
are d riven i nto v arious a mounts o f g ain r eduction, b ut o nce t he a udio f alls b elow t he t hreshold, t hey
"run out of room" or "bottom out," and are incapable of increasing the audio any further. They
require some sort of make-­‐up gain control later in the audio chain. The compressors in Omnia.9
operate a bove A ND b elow t hreshold, c ontrolling t he d ynamics o ver a m uch w ider r ange.
The Gate Threshold and Freeze Threshold controls work together to determine the points
at w hich t he r elease r ate o f t he I nput A GC s lows b y a f actor o f 3 ( gate t hreshold) o r f reezes
altogether (freeze threshold). The range of these controls is -­‐90dB to 0dB. Lower settings
means the audio must drop to a lower level before the release speed slows or freezes.
Higher s ettings m eans t he a udio d oesn't h ave t o d rop a s m uch i n l evel b efore t he i nput A GC
gain s lows d own o r s tops.
Using higher settings when employing faster Input AGC release speeds can keep the audio
from b eing i ncreased t oo q uickly o r t oo m uch d uring q uieter p assages o r p auses.
The Ratio control determines how much the output audio will be increased or decreased in
relationship to the input audio of the Input AGC section. For example, a ratio of 3:1 means
for every 3dB of change in the level of the input audio, the output will be changed by 1dB.
Lower (looser) settings provide less control of the dynamics in this section but provide a
more open sound, while higher (tighter) settings provide more control at the expense of
openness. T he r ange o f t his c ontrol i s 1 .0:1 t o I nfinity:1
The Maximum Gain control works in conjunction with the Ratio control to determine how
much gain is available below threshold. If the Input AGC Ratio is set at Infinty:1 and the
Input A GC M aximum G ain i s s et t o 3 6dB, t he I nput A GC h as 3 6dB o f r ange b elow t hreshold.
At a r atio o f 2 .0:1 a nd t he s ame M aximum g ain s etting, t he r ange i s r educed b y h alf t o 1 8dB.
The scale to the left of the Input AGC meter automatically adjusts as needed when changes
are m ade t o t he I nput A GC M aximum G ain o r t he I nput A GC R atio t o a ccurately r eflect h ow
much r ange i s a vailable b elow t hreshold.
The Attack control determines the speed with which the Input AGC acts to reduce audio
above threshold. Lower settings represent slower attack speeds and allow more audio to
pass unprocessed by the Input AGC into subsequent processing stages. Higher settings
result in faster attack speeds and allow less unprocessed audio to enter subsequent
sections. Because all of Omnia.9's processing stages are to some extent program-­‐
dependent, putting actual measures of time on these controls would be pointless, and so
the numbers on the various Attack and Release controls throughout are simply relative
numbers.
The Release control determines the speed with which the Input AGC increases audio below
threshold. Lower settings provide slower release speeds, while higher settings result in
faster r elease s peeds.
41