Fundamental Requirements: High-Quality Source Material And Accurate Monitoring - Orban OPTIMOD-FM 8500S Operating Manual

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OPERATION
Fundamental Requirements:
High-Quality Source Material and Accurate Monitoring
A major potential cause of distortion is excess peak limiting. Another cause is poor-
quality source material, including the effects of the station's playback machines,
electronics, and studio-to-transmitter link. If the source material is even slightly dis-
torted, that distortion can be greatly exaggerated by OPTIMOD-FM—particularly if a
large amount of gain reduction is used. Very clean audio can be processed harder
without producing objectionable distortion. A high-quality monitor system is essen-
tial. To modify your air sound effectively, you must be able to hear the results of
your adjustments. In too many stations, the best monitor is significantly inferior to
the receivers found in many listeners' homes!
Unfortunately, many contemporary CDs are mastered using levels of audio process-
ing formerly used only by "aggressively-processed" radio stations. These CDs are au-
dibly distorted (sometimes blatantly so) before any further OPTIMOD processing.
The result of 8500S processing can be to exaggerate this distortion and make these
recordings noticeably unpleasant to listen to over the air. There is a myth in the re-
cord industry that applying "radio-style" processing to CDs in mastering will cause
them to be louder or will reduce the audible effects of on-air processing. In fact, the
opposite is true: these CDs will not be louder on air, but they will be audibly dis-
torted and unpleasant to listen to, lacking punch and clarity.
Another unfortunate trend is the tendency to put so much high frequency energy
on the CDs that this energy cannot possibly survive the FM pre-emphasis / de-
emphasis process. Although the 8500S loses less high frequency energy than any
previous Orban processor (due to improvements in high frequency limiting and clip-
ping technology), it is nevertheless no match for CDs that are mastered so bright
that they will curl the vinyl off car dashboards. We hope that the record industry will
come to its senses when it hears the consequences of these practices on the air.
If the waveforms on a given CD are noticeably clipped, it may be possible to improve
the sound by using de-clipping software
off sections of the waveform by extrapolating the clipped-off part of the waveform
from audio that surrounds it. Beyond this, our best advice regarding 8500S process-
ing is to use slow multiband release times and considerable band 4 band 5 cou-
pling, which will not further exaggerate distortion already on the CD.
It is also wise to use a mic processor on talent microphones so that the audio density
of speech material will more closely match that of the music. If you do not use a mic
processor, you can alternatively set up the 8500S's speech-mode processing parame-
ters to create more density than do the music-mode parameters. However, the ex-
ternal mic processor's performance will be more predictable because the 8500S will
detect speech with substantial background music or effects as "music" and will not
apply "speech" mode processing to this material.
1
As of this writing, two audio restoration programs that offer this feature are Dia-
mond Cut DC8 and iZotope Rx.
1 , which attempts to reconstruct the clipped-
ORBAN MODEL 8500S