DISTANCE FROM MICROPHONE
AFFECTS PERFORMANCE
FIGURE1
 
Deaf awareness technology for assistive listening device(s) and inductive loop systems for people who are hearing impaired.
Deaf Awareness Technology

 

Denmark House
35 Denmark Road
Poole
Dorset
BH15 2DE
Tel:
01202 682795
Fax:
01202 682795
www.deaftech.force9.co.uk

Basic Microphone Technique
Good microphone technique will add to your effectiveness a performer. Keep the following points in mind when using a hand held microphone.

1. The distance from the performer or instrument to the microphone has a significant effect on the sound. For increased bass response, get close to the microphone (within 6 inches or less), the closer the microphone is to the sound source, the more the bass response will be increased.

2. Beneficial changes in the level and character of sound coming from the loudspeakers can be achieved by changing your distance from the microphone. For instance, working up close can provide maximum bass enhancement without feedback. Practice and experience will develop your skill in varying your distance to achieve the desired effects.

3. For maximum isolation from other sound sources and background noise, position the microphone as close to the source as practical and aimed at the sound source.

Feedback and Directional Microphones
A performer's worst enemy in using a microphone is feedback. These is a harsh howl or squeal that occurs when the microphone picks up sound from the loudspeakers, re-amplifies and reproduces it over and over again (see Figure 2). This vicious circle results in feedback.

 

MIC WITH CARDIOID POLAR
PATTERN (SHADED) ORIENTED TOWARD
LOUDSPEAKER RESULTS IN FEEDBACK


FEEDBACK LOOP FIGURE 2

 

A directional microphone with a cardioids pickup pattern aids in preventing feedback because it rejects sound that originates from the sides and rear (see Figure 3). Sound pickup from the sides is reduced by about one half, and pickup from the rear is reduced by about nine tenths. You can hear this reduction in pickup by speaking into the microphone as you rotate it from front to back.

If you use your directional microphone close to the performer or instrument, you will ensure that the direct sound will be much louder than the feedback-producing amplified sound. Because less amplifier gain is required to achieve the desired overall loudness, the amplified sound will likely remain below the volume that triggers feedback.

Other hints in preventing feedback:
keep the loudspeakers as far to the sides as possible
be sure that the microphone points toward the performers and away from the loudspeakers
make certain that any stage monitor speakers are positioned in front of the performers and face the insensitive rear of the microphone.

 
MIC WITH CARDIOID POLAR
PATTERN (SHADED) ORIENTED AWAY
FROM LOUDSPEAKERS REDUCES FEEDBACK

CARDIOID MICROPHONE MINIMISES
POSSIBILITY OF FEEDBACK FIGURE 3
 
The cardioids directional characteristics of your microphone are provided by means of rear sound entry. These are ports that cancel sounds originating from the sides and back of the microphone. It is therefore important that these ports not be covered at any time. When holding the microphone, do not allow your hand to partially cover the grille (see Figure 4).

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