Orban Optimod-PC 1101 Operating Manual page 144

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OPERATION ORBAN MODEL 1101
ready controlled without adding excessive density to the audio or re-equalizing to
an unnatural extent.
The M D interacts with the M R . With slower release time
ULTIBAND RIVE ULTIBAND ELEASE
settings, increasing the M control scarcely affects density. Instead, the
D
ULTIBAND RIVE
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 activat-
ing the single-ended noise reduction and/or by carefully setting the M
G
ULTIBAND ATE
control to freeze the gain when the input gets quiet.
T
HRESHOLD
When the release time of the Five-Band compressor is set towards F , the setting
AST
of the M control becomes much more critical to sound quality be-
D
ULTIBAND RIVE
cause density increases as the control is turned up. Listen carefully as you adjust it.
With these fast release times, there is a point beyond which increasing the Five-Band
compressor drive will no longer yield more loudness, and will simply degrade the
punch and definition of the sound. Instead, let the AGC do most of the work.
Because excessive loudness is an irritant in sound for picture, there is almost never
any reason to push processing to the point where it degrades the audio. We recom-
mend no more than 10dB gain reduction as shown on the meters for Band 3. More
than 10dB, particularly with the fast release time, will often create a wall of sound
effect that many find fatiguing.
To avoid excessive density with fast Five-Band release time, we recommend using no
more than 5dB gain reduction in band 3, compensating for any lost loudness by
speeding up the AGC R instead.
ELEASE
Multiband Release; Speech Multiband Release control can be switched to any
of seven settings. To understand how to adjust this control for video programming,
please see the discussion above under MB D .
RIVE
The S control overrides the MB R control when OPTIMOD-
MB R
PEECH ELEASE ELEASE
PC automatically detects speech (page 3-5). You may wish to set the S MB
PEECH
control faster for speech (to maximize smoothness and uniformity) and
R
ELEASE
slower on music (to prevent excessive build-up of density).
Compression Threshold; Speech Compression Threshold controls set the com-
pression threshold for music and speech in each band (following OPTIMOD-PC's
automatic speech/music discriminator), in units of dB. We recommend making small
changes around the factory settings to preserve the internal headroom built into
the processing chain. These controls will affect the spectral balance of the processing
above threshold, but are also risky because they can significantly affect the amount
of distortion produced by the back-end clipping system.
You can use these controls to set independent frequency balances for music and
speech (page 3-5).
MB Gate ("Multiband Gate Threshold") control determines the lowest input level
that will be recognized as program by OPTIMOD-PC; lower levels are considered to
be noise or background sounds and cause the AGC or multiband compressor to gate,
effectively freezing gain to prevent noise breathing.