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USB 7706
Compressor Dual Channel
2.2 Protection Of A System With An Active Crossover
For systems using active crossovers there are two ways to use the compressor. As shown below, the unit may be inser-
ted between the console output and the crossover input. In this application, the compressor will process the entire audio
frequency spectrum.
Alternately, the compressor can be inserted between the output of an active crossover and the input of a power ampli-
fier. In this application it will only affect a specific range of frequencies.
The COMPRESSOR in a two-way System
Compressing the high frequency range with the COMPRESSOR
2.3 Improving The Sound Of A "Processed" System
For our purposes here, let's define a "processed" system as a PA system with a special active crossover whose outputs
are linked via separate power amplifiers to the loudspeakers. Each band has its own limiter whose task it is to limit dan-
gerous signal peaks to a certain level. This process avoids overloading the subsequent power amplifier or destruction of
the loudspeaker. In some units, the crossover frequencies in the crossover unit are further changed during high signal
levels to achieve a "loudness contour" suited to the human hearing. But in many cases, this function leads more to a dis-
turbance than to an improvement of the sound quality. If the compressor is preceding this system, the signal peaks can
be eliminated before they reach the limiters of the processing system. The sound quality therefore remains natural and
free of side effects caused by the changing frequencies of the crossover.
3. USING THE COMPRESSOR WITH TAPE RECORDERS
The COMPRESSOR can be used to prevent saturation of magnetic tape and to improve the signal-to-noise ratio of the
tape machine. In professional recording studios, the saturation level of the tape, system headroom and the output level
of the console are all known quantities, making the application of limiting and compressing very easy. Limiting the audio
levels allows for a higher nominal level of signal to tape, so that the signal-to-noise ratio can be considerably improved.
Using the COMPRESSOR to avoid distortion due to tape saturation
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