18
3 Using Your Microphone
by the speaker. Above a specific volume or
“system gain” setting called the feedback
threshold, the signal starts being regenerated
indefinitely, making the sound system howl and
the sound engineer desperately dive for the
master fader to reduce the volume and stop the
howling.
To increase usable gain before feedback, the
microphone has a supercardioid polar pattern.
This means that the microphone is most sensitive
to sounds arriving from in front of it (your voice)
while picking up much less of sounds arriving
from the sides or rear (from monitor speakers for
instance).main (“FOH”) speakers in front of the
microphones (along the front edge of the stage).
If you use monitor speakers, be sure never to
point any microphone directly at the monitors, or
at the FOH speakers.
Feedback may also be triggered by resonances
depending on the acoustics of the room or hall.
With resonances at low frequencies, proximity
effect may cause feedback. In this case, it is often
enough to move away from the microphone a
little to stop the feedback.