Optimod-Surround 8685 V1.0 Operating Manual - Orban

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OPERATION ORBAN MODEL 8685
Note that the active DIALNORM setting greatly influences the loudness of a given preset.
See Low-IM Look-Ahead Limiter on page 3-13.
Customizing the Settings
The controls in the Five-Band structure give you the flexibility to customize your station
sound. However, as with any audio processing system, proper adjustment of
these controls requires proper balancing of the trade-offs explained above. The following
provides the information you need to adjust the Five-Band structure controls
to suit your programming and taste.
The Five-Band Structure’s Full and Advanced Setup Controls
The tables below summarize the Multiband and Band Mix controls in the dynamics
section. The AGC, Equalizer, Stereo Enhancer, and Clipper controls are common to
both the Two-Band and Five-Band structures and are discussed in their own sections
in Section 3.
MB Drive (“Multiband Drive”) control adjusts the signal level going into the multiband
compressor, and therefore determines the average amount of gain reduction
in the multiband compressor. Range is 25dB.
Adjust the MULTIBAND DRIVE control to your taste and programming requirements.
Used lightly with a slow or medium release time, the Five-Band compressor produces
an open, re-equalized sound that is appropriate for most sound-for-picture programming.
The Five-Band compressor can increase audio density when operated at a
fast or medium-fast release because it acts more and more like a fast limiter (not a
compressor) as the release time is shortened. With fast and medium-fast release
times, density also increases when you increase the drive level into the Five-Band
compressor because these faster release times produce more limiting action. Increasing
density can make loud sounds seem louder, but can also result in an unattractive
busier, flatter, or denser sound. It is very important to be aware of the many negative
subjective side effects of excessive density when setting controls that affect the
density of the processed sound.
Because the 8685’s AGC algorithm uses sophisticated window gating, it is preferable
to make the AGC do most of the gain riding (instead of the multiband compressor),
because the AGC can ride gain quickly without adding excessive density to program
material that is already well controlled. Use the multiband compressor lightly, so it
can achieve automatic re-equalization of material that the AGC has already controlled
without adding excessive density to the audio or re-equalizing to an unnatural
extent.
The MULTIBAND DRIVE interacts with the MULTIBAND RELEASE. With slower release time
settings, increasing the MULTIBAND DRIVE control scarcely affects density. Instead, the
primary danger is that the excessive drive will cause noise to be increased excessively
when the program material becomes quiet. You can minimize this effect by activating
the single-ended noise reduction and/or by carefully setting the MULTIBAND GATE
THRESHOLD control to freeze the gain when the input gets quiet.