Orban OPTIMOD-PC 1101 Operating Manual page 179

OPTIMOD-PC
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 au-
tomatic 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 3-6).
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.
There are two independent gating circuits in OPTIMOD-PC. The first affects the AGC
and the second affects the five-band compressor. Each has its own threshold control.
The multiband silence gate causes the gain reduction in bands 2 and 3 of the five-
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 neigh-
bor), and independently sets the gain of the lowest frequency band according to the
Band Mix
Advanced Name
B2>B1 Coupling
B2>B3 Coupling
B3>B2 Coupling
B3>B4 Coupling
B4>B5 Coupling
B1 Output Mix
B2 Output Mix
B3 Output Mix
B4 Output Mix
B5 Output Mix
B1 On/Off
B2 On/Off
B3 On/Off
B4 On/Off
B5 On/Off
Range
0 ... 100 %
0 ... 100 %
0 ... 100 %
0 ... 100 %
0 ... 100 %
–6.0 ... +6.0
–6.0 ... +6.0
–6.0 ... +6.0
–6.0 ... +6.0
–6.0 ... +6.0
On, Off
On, Off
On, Off
On, Off
On, Off
Table 3-11: MB Band Mix Controls
3-59
OPERATION