Orban OPTIMOD-FM 8600Si, Operating Manual

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OPTIMOD-FM DIGITAL OPERATION
3-3
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Gate LED indicates gate activity, lighting when the input audio falls below the
threshold set by the multiband gate threshold control (with the Full Modify
screen’s
2B G
ATE control). When this happens, the multiband compressor’s recov-
ery time slows drastically to prevent noise rush-up during low-level passages.
•
AGC meter shows the gain reduction of the slow two-band AGC processing that
precedes the multi-band compressor. Full-scale is 25 dB gain reduction. You can
switch the meter so that it reads the gain reduction of the Master (above-200
Hz) band, the Bass (below-200Hz) band, or the difference between the gain re-
ductions in the Master and Bass bands.
The latter reading is useful for assessing the dynamic bass equalization
that the AGC produces, and it helps you set the AGC BASS COUPLING
control.
8600Si PC Remote software provides meters for both AGC bands.
•
HF Enhance meter only appears in Two-Band mode and uses the array ordinar-
ily dedicated to indicating B3 gain reduction. The
HF E
NHANCE meter indicates
the amount of HF boost provided by the dynamic, program-adaptive high fre-
quency enhancer located in the Equalization section. Calibration is in relative
units because the amount of enhancement (in dB) depends on frequency. Be-
cause the left and right HF enhancers are independent, we have programmed
this meter so that it reads the larger of the left and right HF enhancement.
The 8600Si’s HF enhancer operates in both Two-Band and Five-Band
modes and in the 8600Si PC Remote software is metered in both modes.
On the unit’s front panel, there are not enough arrays to meter the HF
enhancer and Five-Band gain reduction simultaneously.
On the 8600Si’s display, the HF Enhancer reads upside down compared to
PC Remote. This is to avoid constantly lighting the red segment at the
bottom of the meter. (Red indicates overload when the meter is indicat-
ing gain reduction.)
•
HF Limiter meter only appears in Two-Band mode and uses the arrays dedi-
cated to indicating B4 and B5 gain reduction in Five-Band mode.
•
The Loudness Level meters, which uses the ITU-R BS.1770-3 algorithm, indi-
cates the relative loudness level at the output of the digital and analog radio
processing chains. They appear only in PC Remote. The reference level for
the analog and digital processing chains are set independently. The loudness
level for the analog radio chain is shown only as a meter on PC Remote. See
BS.1770-3 Loudness Level on page 1-23.
•
The Loudness GR meters, which appear only on PC Remote, indicate the
amount of gain reduction produced by the BS.1770 Safety Limiters in the
digital and analog radio processing chains. The analog FM chain BS.1770 me-
ter is combined with the multiplex power meter in a two-color display.