Omnia Industries Turntable 6FM Manual Do Utilizador

 

 

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could be due to either AC coupling in the STL system or “bounce” generated by either the modulator 
or demodulator of the STL. Sometimes it’s a little of both! 

If you notice any “grass” exceeding the peak level of the low frequency waveforms, there could be noise 
getting into the system. This can occur if the RF path is noisy due to RF signal loss. Such “grass” can also 
be added to the signal if the composite path through the STL system is not linear through the 53 kHz 
bandwidth that a composite signal requires, and this results in overshoots to the processed signal. 

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. 

 
    •     If the Digital STL employs a data reduction codec (compression), we strongly recommend that the 
Omnia-6fm 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 Omnia6-fm 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-6fm 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 Omnia6-fm 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 
Omnia6-fm 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 played on 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