Orban OPTIMOD-FM 8600Si, Operating Manual

Page: 216 / 356

3-50
OPERATION ORBAN MODEL 8600Si
The MX technology peak limiter consists of two main stages—first, a pre-limiter
stage to control low frequency and high frequency peaks ahead of the main peak
limiter and then the main peak limiter, which uses various proprietary techniques to
control distortion, minimize transient loss, and minimize high frequency loss.
The controls affecting this section allow you to trade off loudness, distortion, and
bass energy. Because the laws of physics apply to MX technology, increasing bass in-
creases the likelihood that audible IM distortion between bass and other program
elements will occur. Depending on your station’s format, you may prefer to have a
cleaner sound (with less bass) or a sound with more distortion but punchier bass. We
offer controls, explained below, that allow you to make this tradeoff.
Peak Limiter Drive determines the level applied to the MX peak limiter and thus
how much peak reduction the peak limiter must do. The MX peak limiter uses a va-
riety of tactics to adapt its operation intelligently to the program material applied
to it. Compared to the 8500-style peak limiter, the MX peak limiter produces a dif-
ferent set of artifacts when overdriven. Depending on how you set the other con-
trols, these artifacts may include loss of bass punch, harsh clipping distortion, “soft”
IM distortion, and/or excessive density that can cause fatigue. If you intend to make
adjustments at the intermediate or advanced levels, it is wise to familiarize yourself
with these artifacts by purposely overdriving the peak limiter via the
P
EAK
L
IMITER
DRIVE
CONTROL
and listening to what happens with different types of program ma-
terial.
This control’s range is
±
6 dB relative to an arbitrary 0 dB setting that provides a com-
petitively loud sound without objectionable distortion on most program material.
Settings above 0 dB are likely to produce objectionable distortion with some pro-
gram material, while settings below 0 dB trade off lower loudness for a cleaner
sound.
Bass PreLimit Mode allows you to operate the bass pre-limiter in
M
EDIUM
mode,
which produces some low-order harmonic distortion below 100 Hz,
S
OFT
mode,
which produces essentially no harmonic distortion but may reduce bass punch com-
pared to
M
EDIUM
mode, or
H
ARD
mode, which produces the most distortion but also
the most punch. The modes are very similar to the
S
OFT
and
M
EDIUM
bass clipper
modes in the 8500-style presets. See
B
ASS
C
LIP
M
ODE
on page 3-45.
8500-Style Peak limiter Controls
PC Remote Name Range
Limiter Dr –6.0…+6.0 dB
BassPreLimit 0 … 1
BassPreLimMode Soft, Medium, Hard
BassClpThre –6…+6 dB
Bass Limting 0…–6
Dist Cntrl 0 … 1
Multiband Clipping –4.0…+5.0 dB
Speech BPLim 0 … 1
Table 3-7: MX Technology Peak Limiter Controls