Orban OPTIMOD 8685, Operating Manual

Page: 196 / 357

3-52
OPERATION ORBAN MODEL 8685
2B Bass Coupling is used to set the balance between bass and the rest of the fre-
quency spectrum.
The two-band compressor processes audio in a master band for all audio above ap-
proximately 200Hz, and a bass band for audio below approximately 200Hz. The
B
ASS
C
PL
control determines how closely the on-air balance of material below 200Hz
matches that of the program material above 200Hz.
Bass coupling is set to 100% on all of the two-band presets because these presets
are designed to do gentle gain riding without increasing program density or signifi-
cantly modifying the spectral balance of the program. When bass coupling is set to
100%, the bass band will usually have the same amount of gain reduction as the
master band. Only with material having unusually heavy bass will you see additional
gain reduction in the bass band.
Bass Clip (“Bass Clip Threshold”): See page 3-46.
Loudness Threshold sets the maximum subjective loudness allowed by the process-
ing with reference to the input of the 8685’s MB look-ahead limiter. (See Loudness
Control on page 3-14.)
Advanced Two-Band Controls
The following Two-Band controls are only accessible from the 8685 PC Remote soft-
ware:
2B Master Compression Threshold sets the level where gain reduction starts to
occur in the Master (above 200Hz) band of the Two-Band Compressor.
2B Bass Threshold determines the compression threshold of the bass band (below
200 Hz) in the Two-Band Compressor. It can be used to set the target spectral bal-
ance of the Two-Band Compressor.
LFE Threshold determines the compression threshold of the LFE channel in the
Two-Band Compressor.
Bass>LFE Couple control determines the extent to which the gain of the LFE chan-
nel is determined by and follows the gain of the Bass band. Set towards 0 dB (fully
coupled) this control reduces the amount of dynamic LFE boost, preventing unnatu-
ral exaggeration of material in the LFE channel.
The gain reduction in the LFE audio path is either the output of the Bass compressor
sidechain or the output of the LFE compressor’s band sidechain. The B
ASS
>LFE
C
OUPLING
control sets the switching threshold. For example, if the
B
ASS
>LFE
C
OUPLING
control is set to 4 dB and the Bass gain reduction is 10 dB, the LFE gain re-
duction cannot decrease below 6 dB even if the gain reduction signal from the LFE
compressor sidechain is lower. However, the LFE gain reduction can be larger than
the bass gain reduction without limit. In the previous example, the LFE gain reduc-
tion could be 25 dB.