Digital Stl Use; Monitoring Location; Source Material Quality; Studio Microphone Processing - Omnia 6EX Installation And Operation Manual

why" this occurs, but that could consume a whole chapter by itself!) Simply stated, the problem could be due
to either AC coupling in the STL system or "bounce" generated by the modulator, demodulator, or PLL of the
STL. Sometimes it's a little of each!
If you notice any "grass" exceeding the peak level of the low frequency waveforms, there could be noise or
interference getting into the system. This can occur if the RF path is noisy due to RF signal loss or if on-channel or
adjacent interference is present at the receiver. Such "grass" in the form of ultrasonic overshoots can also be added
to the signal if the signal path through the STL system is not linear within the composite signal bandwidth.
A simple fix for either of these two problems is to employ a composite clipper at the transmitter site. But beware:
Clipping these artifacts can lead to significant audible distortion and degradation of the subcarrier region of the
signal.
While the above items must be given some thought, there are many advantages to installing the processing at the
studio. If the STL link is of late design and operates as designed, superior performance can be achieved, along with
having easy access to the processing for monitoring and adjustment.

Digital STL Use

If the Digital STL employs a data reduction codec (compression), we strongly recommend that the Omnia-6EX be
located at the transmitter site. (See "Pre-Emphasis: Where To Insert" below.) If the Digital STL is a linear system
without data compression, we still recommend placing the processor at the transmitter site. However, the Omnia-
6EX can be placed at the studio if you follow a few guidelines and are willing to accept some limitations. (See
"Interfacing with a Digital STL and/or Exciter" below.) In this scenario, there also must be a provision for a stereo
generator/encoder at the transmitter (most digital exciters provide this function); therefore the composite clipper in
the Omnia-6EX cannot be used. Many exciters include some form of safety clipper or limiter as well, but these can
add distortion and unexpected overshoots if not set up properly.
Monitoring Point
Once Omnia-6EX is on the air, you should select a good acoustical location for monitoring and adjusting it. We feel
that a good tuner with strong reception feeding a good set of studio monitor speakers is probably sufficient. While
car radio and other "typical listener situations" are important in judging the sound of Omnia-6EX against other
stations in your market, they should not be your main reference points. In addition, there should be known-accurate
modulation monitor available. If one is available, connecting an oscilloscope to the composite output of the
modulation monitor will further aid in observing the overshoot performance of the system.
Good, Clean Source Material
A well-respected processing colleague once said, "Garbage in produces more garbage out!" He was not wrong. If
your source material is poor, or poorly performing playback equipment, you will not get maximum sonic benefit
from your processor. Modern audio processors magnify, good or bad, whatever is present in the source material.
Anomalies that you may perceive to be processing problems may in fact be source material problems that are being
exaggerated by the processing. Make sure that you start out with a good first step—good source material.

Studio Microphone Processing

This may appear trivial, but the perceived sound of "live" voices over the air can change dramatically with different
microphone processing systems. There is a high probability that the sound of your on-air microphones will change
when you change on-air processors. If you utilize microphone processing, you may have to readjust it to suit the
operation of your new processing system. Most announcers develop a "comfort zone" with respect to how they
perceive their voice on the air, especially in their headphones. When that "comfort zone" is changed or modified, a
common response is that "something is wrong" with the on-air sound. Microphone processing can be a very
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