Multiband Limiter Windows
The controls in these adjustment windows are similar in function to the previously described AGC stages. However,
there are only four controls for the limiters. The Attack and Release controls work similarly to the AGC sections, but
are of course much faster on overall action. There are also two new parameters as well.
The first is the
Hold Thresh
old. This control sets
the threshold where the limiter’s
Hold
algorithm
begins when it detects pauses in the audio. When
it’s in the
OFF
position, the limiters will attack,
and then release completely, just as you would
expect them to. With
Hold
Thresh
old enabled, the
limiters will momentarily stop and rest during very
short pauses, especially during live speech.
Functionally, this is similar to how the
Gate
function works in the preceding AGCs. The other
control is
Limit
Thresh
old
.
This control sets the
threshold where audio peak limiting begins. Care is
needed when adjusting this control because
raising
the threshold (counter-clockwise) causes less
limiting to occur, and the resulting uncontrolled peak energy will go to the clipper instead. Thus, with this control
you can artistically trade off the dynamic limiting against brick wall clipping, as each has its own “sound.”
As the limiter threshold is lowered by turning the
Limit Thresh
control clockwise, the peak output level of the
limiter is reduced. The signal in that band won't hit the clipper as hard, and you'll notice more action on the limiter
bargraph for that band. In fact, instead of reducing the output of one of the audio bands in the Final Mixer section,
you could instead “dynamically reduce” the level in that band (which also increases density in that band) by
lowering the limiter threshold.
When adjustments are made to limiter thresholds, start by making adjustments in 0.5dB steps. Reducing the
threshold too much can cause the system to create an effect that “sucks out” the frequencies in that band.
Conversely, the opposite (raising the threshold) will create an exaggerated effect by over-enhancing certain
frequency ranges, as well as causing increased distortion, since excessive levels from that band will reach the
following clipper stage. Usually, the limiter thresholds are adjusted as a “fine polish” on the final sound. If you are
unsure about how to use the
Limiter Thresh
olds, then we recommend that they be left at their well-researched
factory settings.
Omnia-6ex Use and Operation Manual – V: 1.10
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