Glossary - Shure MUSIC EDUCATORS Manual

Glossary

3-to-1 Rule – When using multiple
microphones, the distance between
microphones should be at least 3 times
the distance from each microphone
to its intended sound source.
Automatic Mixer – A specialized
mixer that turns off unused microphone
channels without any user intervention,
and turns on microphone channels as
needed.
Boundary/Surface Microphone –
A microphone designed to be mounted
on an acoustically reflective surface.
Cardioid Microphone – A unidirectional
microphone with moderately wide front
pickup (131 degrees). Angle of best
rejection is 180 degrees from the front of
the microphone, that is, directly at the rear.
Close Pickup – Microphone placement
within 2 feet of a sound source.
Compressor – A device that controls
varying signal levels.
Condenser Microphone – A microphone
that generates an electrical signal when
waves vary the spacing between two
charged surfaces: the diaphragm and
the backplate.
Decibel (dB) – A number used to
express relative output sensitivity.
It is a logarithmic ratio.
Delay (echo) – Reflection of sound that
is delayed long enough to be heard as a
distinct repetition of the original sound.
Music
Educators
Guide
Dynamic Microphone – A microphone
that generates an electrical signal when
sound waves cause a conductor to
vibrate in a magnetic field. In a moving-coil
microphone, the conductor is a coil of
wire attached to the diaphragm.
EQ – Equalization or tone control to shape
frequency response in some desired way.
Feedback – In a PA system consisting of
a microphone, amplifier, and loudspeaker,
feedback is the ringing or howling sound
caused by amplified sound from the
loudspeaker entering the microphone
and being re-amplified.
Flat Response – A frequency response
that is uniform and equal at all frequencies.
Frequency – The rate of repetition of a
cyclic phenomenon such as a sound
wave. Usually measured in Hertz (Hz).
Frequency Response – A graph
showing how a microphone responds
to various sound frequencies. It is a
plot of electrical output (in decibels)
vs. frequency (in Hertz).
Gain – Amplification of sound level or
voltage.
Gain-Before-Feedback – The amount
of gain that can be achieved in a sound
system before feedback or ringing occurs.
Headworn Microphone – A microphone
designed to be worn on the head.
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