Fundamental Requirements: High-Quality Source Material And Accurate Monitoring - Orban OPTIMOD 5750 Operating Manual

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Orban 5750 Technical Manual Operation
and that Management fully understands the trade-offs involved in optimizing one parameter (such as loudness) at
the expense of others (such as distortion or excessive density).
Never lose sight of the fact that, while the listener can easily control loudness, he or she cannot make a distorted
signal clean again. If such excessive processing is permitted to audibly degrade the sound of the original program
material, the signal is irrevocably contaminated and the original quality can never be recovered.
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 distorted, that distortion can be greatly exaggerated by the OPTIMOD-5750—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 essential. 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 processing formerly used only by
"aggressively-processed" radio stations. These CDs are audibly distorted (sometimes blatantly so) before any further
OPTIMOD processing. The result of 5750 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 record 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 distorted 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 5750 loses less high frequency energy
than many previous Orban processors (due to improvements in high frequency limiting and clipping 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, which attempts to reconstruct the clipped-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 5750 processing is to use
slow multiband release times and considerable band 4 to band 5 coupling, which will not further exaggerate
distortion already on the CD. As of this writing, two audio restoration programs that offer de-clipping are Diamond
Cut DC8 and iZotope Rx.