Orban OPTIMOD 6300 Operating Manual page 90

2-36
INSTALLATION
Turning down the DO1
without significantly affecting the average modulation. Hence, using this
technique keeps the 6300's L
provides correct on-air loudness.
O) Check loudness with respect to other stations in your market and correct your
average modulation if necessary.
You have just adjusted on-air loudness to match the loudness that an Op-
timod-TV 8382 would produce when set up normally. However, because
there is no standard value for the average modulation in analog TV
transmission, the loudness of your analog transmission might be different
from other stations in your area. If this is so, match the 6300's loudness to
the other stations by adjusting the D
In PC Remote, this control is located in the L
front panel, the control is located in A
changing D
IALNORM
louder. Adjusting D
ness after the system has been calibrated according to steps (M) and (N)
above; this technique will retain correct calibration of the 6300's loudness
level meter and loudness controller.
Note that increasing the loudness in this way will increase the likelihood
that the 6300's look-ahead limiter will create audible "pumping" or
"gulping" artifacts on program material that is rich in high frequencies
because the look-ahead limiter is operating on a preemphasized signal
and turning up D
such artifacts, we recommend that you use a 5-Band TVA preset if you
are not doing so already. This allows you to use the Band 5 compres-
sor/limiter as a high-frequency limiter. If you hear audible pumping on
material rich in high frequencies, turn down the B5 T
until you find the most subjectively pleasing trade-off between high fre-
quency loss and look-ahead limiter pumping. You can also try speeding
up the B5 A
TTACK
the both controls to taste.
When you use a 2-Band "TVA" preset, some material rich in high fre-
quencies may cause subtle pumping even with
nal –17 dB value. This is because the 2-band compressor cannot produce
high frequency limiting, so preemphasis control must be performed by
the loudness controller and look-ahead limiter. We have tuned the 5-
Band factory "TVA" presets to produce appropriate amounts of high-
frequency limiting. We therefore recommend that if you need to use a
"TVA" preset, use a 5-Band preset unless you have a very good reason
not to.
P) Navigate to S
ETUP
(11.A) through (11.L) for Digital Output 2.
You can freely set the DO2 controls to achieve whatever goals you want
without compromising the calibration of digital output 1 with respect to
Dialnorm. If you assign DO2 to MB+LIM and set the DO2 100% control to
be the same as the DO1 100% control, DO2 will also emit a signal prop-
erly calibrated to drive a Dolby Digital encoder.
100%
control reduces the peak modulation
L
OUDNESS EVEL
IALNORM
from –17 dB to –15 dB makes the transmission 2 dB
is the only correct way to adjust on-air loud-
IALNORM
drives the look-ahead limiter harder. If you hear
IALNORM
control by setting it to a lower number, or adjusting
> IO C > D C
ALIB IGITAL
ORBAN MODEL 6300
meter correctly calibrated and
control in the on-air preset.
-M
ESS ORE tab; on the 6300's
M
DVANCED ODIFY . For example,
HRESHOLD
D
IALNORM
set to its nomi-
> DO2 C
ALIB ALIB and execute steps
control