Orban Optimod-PC 1101, Руководство по эксплуатации

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OPTIMOD-PC INSTALLATION
2-41
C) If the Dialnorm
R
EFERENCE
S
OURCE
in
I/O M
IXER
>
C
ONFIGURATION
is set
O
FF
,
you can use the
L
OUDNESS
M
ETER
S
ENSITIVITY
to scale the loudness meter’s sen-
sitivity so that it indicates on-scale. This is mainly useful to allow you to com-
pare the loudness of the 1101’s “radio-style” presets and to assess the effect
of customizing those presets.
D) If you wish to save the entire setup (that is, the settings of all controls in all
tabbed pages), click
S
AVE
S
ETUP
on the File menu in the Orban Control appli-
cation. Then follow the prompts.
Saving a setup is useful mainly if you wish to be able to paste this entire
setup to another OPTIMOD-PC card later. Any changes you have made to
the setup of the currently active card will be saved automatically for that
card when you click
D
ONE
; it is unnecessary to use S
AVE
S
ETUP
to avoid
losing changes you made. See step (2.B) on page 2-21.
The next two headings are only relevant to processing for Dolby Digital transmission
channels and can otherwise be ignored.
Setting Output Loudness in Dolby Digital transmissions
When you have assigned the
D
IALNORM
O
UTPUT
(
in the
C
ONFIGURATION
tab of the I/O
mixer
)
to the 1101 output driving the Dolby Digital channel, that output’s attenu-
ator no longer adjusts loudness. Instead, it sets the 1101’s maximum peak output
level with respect to 0 dBfs, which allows you to compensate for transmission chan-
nels that introduce peak overshoots. For example, if you lower an output control
from 0 dBfs to –2 dBfs, the 1101 automatically reduces the gain following its peak
limiter by 2 dB and simultaneously increases the drive into the look-ahead limiter by
2 dB. Hence, the average output level does not change but the maximum peak out-
put level is constrained to –2 dBfs
2
. This unconventional arrangement results from
the 1101’s handling of Dialnorm—if you have set
D
IALNORM
R
EFERENCE
correctly on
the 1101, you can change the output level control freely without causing your loud-
ness to be incorrect with respect to other transmissions.
To set the output loudness, adjust the
D
IALNORM
value or adjust the
MB L
IMITER
D
RIVE
control in the active processing preset. Both methods cause 1101’s
O
UTPUT
L
EVEL
me-
ter indication to change.
•
Adjusting Dialnorm changes output loudness without changing the indication
on the 1101’s CBS Loudness Level meter or the amount of gain reduction in
the loudness controller. The peak limiter’s gain reduction will change. This is
the preferred method if the 1101’s loudness controller is active because it has
the smallest effect on the sonic texture of the 1101’s audio processing.
2
If this causes large amounts of gain reduction to occur in the look-ahead limiter,
the average level will decrease somewhat. However, this will only happen with
pathologically high settings of Dialnorm and will never happen at the settings of
D
IALNORM
typically used in broadcasts (–24 per ATSC A/85 or –23 per EBU R128).