Orban OPTIMOD-FM 8600, Operating Manual

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3-100
OPERATION ORBAN MODEL 8600
The 8600 also uses a psychoacoustic model, but in a far more sophisticated way that
has some similarities to audio codec technology.
Figure 3-6 on page 3-98 is a twelfth-octave ratio that compares the spectrum of the
8500 and 8600 outputs in a more detailed way than the third-octave ratio seen in
Figure 3-5. It shows the 8600’s 4.6 dB suppression of (mainly harmonic) clipping dis-
tortion centered at 3.668 kHz caused by sustained electric guitar riding on top of
bass.
Figure 3-7 on page 3-99 shows a piece of material that has been used by others to
demonstrate distortion control. This material consists of Clarkson’s humming over a
quiet piano background. There is little program energy in the upper midrange, so
any clipper-induced distortion tends to stand out.
Figure 3-8
Level 42, “Starchild”
The twelfth-octave ratio shows as much as 4 dB suppression of narrowband differ-
ence-frequency IM distortion in the midrange. To cause the 8500 to produce notice-
able distortion, we used the IMPACT preset, which is a louder preset than GREGG or