FONESTAR MX-875-SR Guía Rápida página 4

EN
ACOUSTIC FEEDBACK DETECTION
One of the main characteristics of the mixer/preamplifier MX-875-SR is that of eliminating coupling or
acoustic feedback in the inputs connected to it.
Acoustic feedback is produced when the sound reproduced by the loudspeakers is recaptured by the
microphone to be amplified again. It is known as the Larsen effect. It can be due to a bad distribution of
microphones in a room, to the acoustic conditions of the premises and excessive amplification.
The feedback suppressor eliminates coupling by displacing, the audio signal frequency, by a few herz, using
a highly accurate oscillation. This way it avoids acoustic feedback being produced at a frequency favoured
by the amplification system and the characteristics of the premises.
In order for the feedback suppressor to start operating, it must detect which of the microphone inputs is
producing this effect, attenuate the gain level of that input until the exact point in which coupling with the
microphone can be observed and activate the feedback suppressor using the buttons.
If no acoustic feedback is detected, it is not necessary to activate the feedback suppressor, as the sytem's
response will be weakened at unnecessarily high frequencies.
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