Orban Optimod-AM 9400, Operating Manual

Page: 188 / 295

3-54
OPERATION ORBAN MODEL 9400
back and forth randomly if the stereo content is right at the stereo /
mono detector’s threshold. Mono music with a “speech-like” envelope
may be incorrectly detected as “speech.” Music incorrectly detected as
“speech” will exhibit a slight loss of loudness and punch, but misdetec-
tion will never cause objectionable distortion on music.
Speech that is not located in the center of the stereo sound field will al-
ways be detected as “music” because the detector always identifies ste-
reo material as “music.” This can increase clipping distortion on such
speech.
Because the speech detector uses information about the stereo sound
field to help make its detection more accurate, it is important to feed the
9400 with stereo source material even if it is only being used to drive a
monophonic AM analog transmitter.
If the
B
ASS
C
LIP
M
ODE
is set to
H
ARD
, the speech/music detector will auto-
matically set it to M
EDIUM
when speech is detected and H
ARD
otherwise
(unless L
ATENCY
is L
OW
, in which case M
EDIUM
bass clipping is unavailable
and bass clipping will stay H
ARD
).
Speech always sounds cleaner with
M
EDIUM
bass clipping and the in-
creased bass “punch” supplied by
H
ARD
is irrelevant to speech.
This control does not affect the digital radio processing chain.
Test Modes
Setup: Test
Parameter
Labels Units Default Range (CCW to CW) Step
MODE --- Operate Operate, Bypass, Sine, Square,
Triangle ---
BYPASS GAIN dB 0.0

18 … +25
1
SINE FREQ Hz 400 16, 20, 25, 31.5, 40, 50,
63, 80, 100, 125, 160,
200, 250, 315, 400, 500,
630, 800, 1000, 1250, 1600, 2000,
2500, 3150, 4000, 5000,
6300, 8000, 9500, 10000, 12500,
13586.76, 15000
LOG
SQUARE FREQ Hz 400 16, 20, 25, 31.5, 40, 50,
63, 80, 100, 125, 160,
200, 250, 315, 400, 500,
630, 800, 1000 LOG
TRI FREQ Hz 100 Fixed at 100 Hz
SINE/TRINGL MOD % 100 0 … 121 1
SQUARE MOD % 30 0 … 50 1
TONE CHAN --- L+R
L+R, L

R, LEFT; RIGHT
---
Table 3-10: Test Modes
The Test Modes screen allows you to switch between O
PERATE
, B
YPASS
, and S
INE
,
S
QUARE
, or T
RIANGLE
. When you switch to B
YPASS
or any tone mode (sine wave,