Orban OPTIMOD-FM 8700, Operating Manual

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3-82
OPERATION ORBAN MODEL 8700i
rately. The I
NDEPENDENT
mode allows you to set the HD equalizer and HD multiband
compressor/limiter audio controls independently of their FM counterparts.
I
NDEPENDENT
mode exposes HD controls that are hidden in FM

HD mode.
If a given preset has certain HD and FM controls set differently, setting the FM

HD
C
ONTROL
C
OUPLING
to C
OUPLED
will immediately cause the HD controls to take the
same settings as their FM analog counterparts.
On 8700i PC Remote, there are buttons available on the button bar to toggle the
FM

HD mode. When the FM

HD mode is I
NDEPENDENT
, a button on the toolbar
toggles between corresponding FM and HD tabs (for example, between
C
OMPRESSORS
and HD C
OMPRESSORS
).
HD EQ Gain determines the depth of high frequency shelving equalization produced
by the parametric HF shelving equalizer, which will be placed either before or after
the digital-channel look-ahead limiter (depending on the setting of the
HD HF S
HELF
EQ control in the I
NPUT
/ O
UTPUT
HD D
IGITAL
R
ADIO
screen).
When placed before the look-ahead limiter, this equalizer is sometimes
useful for reducing the audible disparity between the FM and digital-
channel outputs (although the
HD B
AND
M
IX
controls are probably more
appropriate for this task). The digital-channel output receives no high
frequency limiting or clipping and may therefore be as much as 6 dB
brighter than the FM output. If you wish to reduce this difference to
smooth out the audible difference between the two channels during a
receiver crossfade, you can apply HF rolloff to the digital-channel channel
by ear. Another reason you might want to do this is if the digital-channel
channel sounds excessively bright after you have optimized the 8700i’s
tuning for FM. Of course, you can also use the
HD MB B
AND
M
IX
controls
for this purpose, or use these controls in conjunction with the HF shelving
equalizer.
Yet another reason to use HF rolloff in the digital-channel channel is to
reduce codec artifacts at the high frequencies—the familiar “watery”
sound.
When placed after the look-ahead limiter, the shelving EQ can reduce the
effects of codec overshoot.
The parametric HF shelving equalizer can only produce HF rolloff. It can-
not boost.
HD EQ Freq sets the corner frequency of the parametric HF shelving equalizer.
HD Limiter Dr sets the drive level to the digital-channel look-ahead limiter.
When the BS.1770 Safety Limiter is active, you must use the HD L
IMITER
D
R
control to
set the amount of gain reduction that the BS.1770 Safety Limiter produces. See step
22.C) on page 2-41.
The factory default is +4 . When the BS.1770 Safety Limiter is active, the
HD L
IMITER
D
R
control will usually need to be set substantially below 0 dB
unless the preset is quiet (like one of the C
LASSICAL
presets).