Orban OPTIMOD 6300 Operating Manual page 202

3-60
OPERATION
Note also that it is virtually impossible to achieve undetectable dynamic noise reduc-
tion of program material that is extremely noisy to begin with, because the program
never masks the noise. It is probably wiser to defeat the dynamic noise reduction
with this sort of material (traffic reports from helicopters and the like) to avoid ob-
jectionable side effects. You must let your ears guide you.
Band 5 is particularly critical for noise reduction because much of the Downward Ex-
pander's utility lies in hiss reduction. Hiss has most of its energy in band 5, while
program material typically has less energy in this band, so the B5 D
D T
control's setting is critical to removing hiss while minimizing re-
ELTA HRESHOLD
moval of desired program energy.
Starting in V1.1, the Downward Expander's dynamic frequency response is no longer
constrained to being strictly lowpass—Band 5 is now uncoupled from the lower
bands, so the band 5 downward expander can produce less gain reduction than
other bands. This can help prevent loss of desired high frequency material in the
program.
B3>B4 CPL ("Band 3>4 Coupling") control determines the extent to which the gains
of bands 4 (centered at 3.7 kHz) and 5 (above 6.2 kHz) are determined by and fol-
lows the gain of band 3 (centered at 1 kHz). Set towards 100% (fully coupled) this
control reduces the amount of dynamic upper midrange boost, preventing unnatu-
ral upper midrange boost. The gain of band 5 is further affected by the B4>B5 CPL
control.
The C
controls use an "OR" algorithm: the final gain reduction in a given
OUPLING
band is the higher of (1) the gain reduction that would have been produced in that
band with no coupling, OR (2) the gain reduction in the adjacent coupled band mul-
tiplied by the setting of the C
For example, assume that Band 4 would produce 10 dB of gain reduction with no
B3>B4 coupling. If the B3>B4 C
4's gain reduction unless Band 4 is producing more than 20 dB of gain reduction. At
this point, every 2 dB increase in Band 4's gain reduction will cause a 1 dB increase in
Band 3's gain reduction.
B4>B5 CPL ("Band 4>5 Coupling") controls the extent to which the gain of band 5
Band Mix
Full Name Advanced Name
B2>B1 CPL B2>B1 Coupling
B2>B3 CPL B2>B3 Coupling
B3>B2 CPL B3>B2 Coupling
B3>B4 CPL B3>B4 Coupling
B4>B5 CPL B4>B5 Coupling
B1 OUT B1 Output Mix
B2 OUT B2 Output Mix
B3 OUT B3 Output Mix
B4 OUT B4 Output Mix
B5 OUT B5 Output Mix
OUPLING control.
control is set to 50%, Band 3 will not affect Band
PL
Range
0 ... 100 %
0 ... 100 %
0 ... 100 %
0 ... 100 %
0 ... 100 %
–6.0 ... +6.0 dB
–6.0 ... +6.0 dB
–6.0 ... +6.0 dB
–6.0 ... +6.0 dB
–6.0 ... +6.0 dB
Table 3-11: MB Band Mix Controls
ORBAN MODEL 6300
E
OWN XPANDER