Orban OPTIMOD 6300 Operating Manual page 200

3-58
OPERATION
see the discussion above under MB D
The S MB R
PEECH ELEASE
PC automatically detects speech (page 3-6). You may wish to set the S
R
control faster for speech (to maximize smoothness and uniformity) and
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 look-ahead limiter.
You can use these controls to set independent frequency balances for music and
speech (page 3-6).
MB GATE ("Multiband Gate Threshold") control determines the lowest input level
that will be recognized as program by OPTIMOD 6300; 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.
The multiband gate only works appropriately when the K
all bands are set identically, which is typically the case in broadcast applications. We
recommend turning off the multiband gate if the individual K
are unequal.
There are two independent gating circuits in the 6300. The first affects the AGC and
the second affects the multiband compressor. Each has its own threshold control.
The multiband silence gate causes the gain reduction in bands 2 and 3 of the multi-
band compressor to move quickly to the average gain reduction occurring in those
bands when the gate first turns on. This prevents obvious midrange coloration un-
der gated conditions, because bands 2 and 3 have the same gain.
The gate also independently freezes the gain of the two highest frequency bands
(forcing the gain of the highest frequency band to be identical to its lower
neighbor), and independently sets the gain of the lowest frequency band according
to the setting of the DJ B
out introducing obvious coloration, the gating smoothly preserves the average
overall frequency response "tilt" of the multiband compressor, broadly maintaining
the "automatic equalization" curve it generates for a given piece of program mate-
rial.
MB GATE
control is turned
If the
tion screen) is disabled.
DwnExp Thr ("Downward Expander Threshold") determines the level below which
the single-ended noise reduction system's downward expander begins to decrease
system gain and below which the high frequencies begin to become low-pass fil-
tered to reduce perceived noise. There are two controls: the MB D
RIVE .
control overrides the MB R
boost control (in the Equalization screen). Thus, with-
ASS
O
, the
FF
ORBAN MODEL 6300
control when OPTIMOD-
ELEASE
and R
NEE ATIO
and R
NEE
DJ B
control (in the Equaliza-
ASS
MB
PEECH
controls of
settings
ATIO
E
OWN XPANDER