Optimod-AM 9400 V1.2 Operating Manual - Orban

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OPERATION ORBAN MODEL 9400
audible distortion with almost any program material. Large changes in the frequency
balance of the compressor outputs will change this tuning, leaving the 9400
more vulnerable to unexpected audible distortion with certain program material.
Therefore, you should make large changes in EQ with the bass and parametric
equalizers and the HF enhancer, because these are located before the compressors.
The compressors will therefore protect the system from unusual overloads caused by
the chosen equalization. Use the multiband mix controls only for fine-tuning.
You can also get a similar effect by adjusting the compression threshold of the individual
bands. This is comparably risky with reference to clipper overload, but unlike
the MB BAND MIX controls, does not affect the frequency response when a given band
is below threshold and is thus producing no gain reduction.
Advanced Multiband Controls
The following Advanced Multiband controls are available only from 9400 PC Remote
software.
Bx On / Off switches allow you to listen to any band (or any combination of bands)
independently. This is a feature designed for intermediate or advanced users and
developers when they are creating new 9400 presets.
Please note that a single band will interact with the back-end clipping system quite
differently than will that band when combined with all of the other bands. Therefore,
do not assume that you can tune each band independently and have it sound
the same when the clipping system is processing all bands simultaneously.
B1-B5 Attack (Time) controls set the speed with which the gain reduction in each
band responds to level changes at the input to a given band’s compressor. These
controls, which have never previously been available in an Orban processor, are risky
and difficult to adjust appropriately. They affect the sound of the processor in many
subtle ways. The main trade-off is “punch” (achieved with slower attack times) versus
distortion and/or pumping produced in the clipping system (because slower attack
times increase overshoots that must be eliminated in the clipping system). The
results are strongly program-dependent, and must be verified with listening tests to
a wide variety of program material.
The ATTACK time controls are calibrated in arbitrary units. Higher numbers correspond
to slower attacks.
In the analog AM channel, the look-ahead delay times in bands 3, 4, and 5 automatically
track the setting of the ATTACK time controls to minimize overshoot for any
attack time setting.
High Frequency Limiter (AM chain only) sets the amount of additional gain reduction
occurring in band 5 when high frequency energy would otherwise cause excessive
distortion in the final clipper. It uses an analysis of the activity in the final clipper
to make this determination, and works in close cooperation with the band-5 multiband
clipper. Functionally, this control is a mix control that adds a HF limiter gain reduction
signal to the band 4 gain reduction signal to determine the total gain re-