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AM-10HD / Aug 2008
A M - 1 0 H D G U I
Gated Modes
The “Gated Mode” controls determine how the AGC behaves in the absence
of audio.
Ooze
When “Ooze” is selected and the audio input falls below the AGC Gate
Threshold, rather than the bands “freezing” they gains, their will slowly return
towards 0dB. This setting may be useful for formats that contain material with
very wide dynamic range or for certain speech‑based formats where the “Gate
Hold” setting may not be appropriate.
Note that the time between achieving the Gate Threshold and the actual gain
transition to Ooze is determined by the setting of the Gate Delay control.
Hold
When “Hold” is selected and the audio falls below the AGC Gate Threshold
value the gains of the five bands will “freeze” at their current values and will
hold at those values until audio is present that is above the AGC Gate Threshold.
This prevents the increasing of gain in the absence of audio which would likely
increase background noise.
Note that the time between reaching the AGC Gate Threshold and the instant
when actual gain Hold begins is determined by the setting of the Gate Delay
control.
Gate Delay
The Gate Delay control sets how long the gating circuit waits after the
signal has fallen below the Gate Threshold before it modifies the release time
according to the “Gated Mode” setting. The Gate Delay is adjustable from
50 milliseconds to 500 milliseconds, with values on the order of 50 milliseconds
being useful for typical programming environments.
When Gate Delay is adjusted for longer periods of time beyond about
100 milliseconds, partial release of all bands is afforded when the input signal
falls below the actual Gate Threshold. This can be useful for maintaining a more
natural drop in signal level during program fades.
The controls in the Gate section are quite subjective and therefore should be
adjusted entirely by the requirements of the program format. There is no right or
wrong setting of the controls unless those settings cause undesired, unexpected,
or unwanted behavior of the processor during low level program passages.
