AKG C 451B Bedienungshinweise Seite 16

3 Application
Refer to fig. 3.
Preattenuation
Pad
Fig. 4:
Preattenuation
switch.
16
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 cardioid polar pattern. This
means that the microphone is most sensitive to
sounds arriving from in front of it (from the sound
source) while picking up much less of sounds
arriving from the sides or rear (from monitor spea-
kers for instance).
To get maximum gain before feedback, place the
main ("FOH") speakers in front of the micro-
phones (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.
3.4
electrical output signal of the transducer may
become high enough to overload the subsequent
impedance converter/preamplifier and introduce
If you are miking up an
extremely loud sound
source or have placed
the microphone ex-
tremely close to an
instrument, the dia-
phragm may be ex-
posed to extremely
high sound pressure
levels. As a result, the