3-22
OPERATION
ORBAN MODEL 9300
will also require that the listener tune the radio more carefully.
If most of your listeners have wider-band radios (as may be the case in North Amer-
ica), use the NRSC curve, which can be chosen with the
HF
C
URVE
control. For a
somewhat brighter sound that can benefit narrowband radios more, yet is still com-
patible with wideband NRSC radios, use
HF
C
URVE
= 10 and
HF
G
AIN
= 10dB.
HF
C
URVE
= 10 corresponds to the RED preemphasis module in Orban's analog
9100-series OPTIMOD-AM processors.
Note that the added brightness caused by using an
HF
C
URVE
of 10 (as opposed to
using NRSC) may tend to increase the first-adjacent interference being generated by
your station, contrary to the purpose and intentions of the NRSC.
HF
C
URVE
settings between 0 and 10 smoothly interpolate between the two ex-
tremes, and provide more flexibility for user adjustment. An
HF
C
URVE
setting of 5
provides the curve family associated with the YELLOW preemphasis module in
Orban's analog 9100-series OPTIMOD-AM processors.
With the
HF
C
URVE
control at any setting other than
NRSC
, extreme amounts of
high-frequency boost may result in a slight `lisping' quality on certain voices. This is
because the high-frequency boost will increase the high-frequency content of sibi-
lant voices, which can only be boosted to 100% modulation. Since the spectral bal-
ance of the voice is altered, this may be perceived as a lisping sound.
The receiver equalizer is of limited benefit to narrowband radios with abrupt rol-
loffs. We believe that these radios benefit more from a boost at 3 kHz, combined
with very little HF shelving EQ. These radios have almost no response at 5 kHz and
above, so boosting frequencies above 5 kHz wastes modulation. Using a bell-shaped
boost at 3 kHz causes the boost to decline naturally at frequencies that the radio
cannot reproduce. You can use either the midrange or HF parametric equalizer to
create such a boost.
This technique can also be useful if you are limiting your transmitted audio band-
width to 5 or 6 kHz, which is required in much of the world and is becoming more
common in North America. OPTIMOD-AM’s sharp lowpass filters (necessary to con-
trol occupied RRF bandwidth adequately) can produce audible ringing, which many
people find objectionable. By limiting the amount of boost at the cutoff frequency
of the OPTIMOD-AM lowpass filter, you can reduce the audibility of filter ringing.
DJ BASS
(“DJ Bass Boost“) control determines the amount of bass boost produced
on some male voices. In its default
O
FF
position, it causes the gain reduction of the
lowest frequency band to move quickly to the same gain reduction as its nearest
neighbor when gated. This fights any tendency of the lowest frequency band to de-
velop significantly more gain than its neighbor when processing voice because voice
will activate the gate frequently. Each time it does so, it resets the gain of the lowest
frequency band so that the gains of the two bottom bands are equal and the re-
sponse in this frequency range is flat. The result is natural-sounding bass on male
voice.
If you like a larger-than-life, “chesty” sound on male voice, set this control
O
N
,
which allows band 1 and band 2 to be gated independently.
Summary of Contents for OPTIMOD-AM 9300
Page 1: ...Operating Manual OPTIMOD AM 9300 Digital Audio Processor Version 2 0 Software...
Page 7: ...Operating Manual OPTIMOD AM 9300 Digital Audio Processor Version 2 0 Software...
Page 178: ...3 46 OPERATION ORBAN MODEL 9300...
Page 200: ......
Page 221: ...OPTIMOD AM DIGITAL TECHNICAL DATA 6 21...
Page 222: ...6 22 TECHNICAL DATA ORBAN MODEL 9300 CONTROL BOARD PARTS LOCATOR...
Page 228: ...6 28 TECHNICAL DATA ORBAN MODEL 9300...
Page 229: ...OPTIMOD AM DIGITAL TECHNICAL DATA 6 29 I O DSP BOARD LEFT AND RIGHT ANALOG INPUTS...
Page 230: ...6 30 TECHNICAL DATA ORBAN MODEL 9300 I O DSP BOARD ANALOG OUTPUTS...
Page 231: ...OPTIMOD AM DIGITAL TECHNICAL DATA 6 31...
Page 238: ...6 38 TECHNICAL DATA ORBAN MODEL 9300 FRONT VIEW REAR VIEW FRONT PANEL PARTS LOCATOR DIAGRAM...