Specifications

215
GLOSSARY
human hearing). A 6-dB increase in SPL would
sound about twice as loud.
Deep Fade
Massive decline of received signal strength due
to cancellation of the carrier in multipath
transmission situations.
Directivity Factor
The directivity of a microphone can be
expressed in terms of the amount of sound
energy it absorbs out of a diffuse sound field.
The directivity factor indicates how much less
sound energy is absorbed by a directional
microphone than an omnidirectional micro-
phone.
Distortion
Dynamic microphones virtually never distort the
signal. To be precise, their distortions at very
high sound pressure levels (<130 dB) cannot
be measured because loudspeakers are inca-
pable of reproducing such levels distortion free.
For this reason, we state no maximum SPL for
dynamic microphones.
However condenser microphones with their
built-in preamplifier may overload at high
sound levels. When close miking (from a few
inches) loud instruments such as drums or
trumpets the microphone sensitivity should be
reduced. With the C 535, simply use the preat-
tenuation switch.
Directional Antenna
Antenna whose sensitivity is highest within a
limited angle in front of the antenna.
Directional antennas are used mainly where
standard receiving antennas cannot be mount-
ed within the range of the transmitters so the
transmitter signals must be picked up from
greater distances (e.g., in open-air arenas).
Diversity
Reception technique that ensures clear recep-
tion even in difficult environments. Diversity
receivers use several antennas for the same
carrier frequency and some models use several
receiving sections, too.
Downtime
Period of time during which a system is inoper-
ative.
Dropout
Momentary loss of signal due to squelch opera-
tion or interference.
Dynamic Microphone
A coil attached to a diaphragm is driven by the
sound waves and vibrates between the poles of
a magnet. This movement induces in the coil a
voltage which corresponds to the sound pres-
sure. Dynamic microphones handle high sound
levels without overloading and are very rugged.
They require no operating voltage. Dynamic
microphones from AKG are designated by the
letter “N” in front of the model number. Also
known as “moving coil microphone”.
Electret Condenser Microphone
Condenser microphone that needs no polariza-
Inside a bass
drum 3 cm
(one inch)
from the head
Tom-toms
3 cm (one in.)
distance;
60 watt guitar
amp, at 30 cm
(12 in.)
distance
Loud vocals,
at 15 cm
(6 in.) distance
Acoustic
guitar,
chords
strummed with
plectrum, at
40 cm (16 in.)
Acoustic
guitar, at
40 cm (16 in.)
played
“fingerpicking”
Noise level in
an average
city apparment
Threshold of
hearing
Loud vocals,
measured in front
of the
mouth;
threshold of pain
Congas, 2 cm (one
in.) from the head
Cowbell at
10 cm (4 in.)
distance
Saxophone, trom-
bone, played p,
at 40 cm
(16 in.)
distance
Piano, played pp,
at 1 m
(3 ft.) distance
Whispering at dis-
tance of
10 cm (4 in.) quiet
conversation at 1
m (3 ft.) distance
Noise level in a
good sound-iso-
lated studio
140 dB
130 dB
120 dB
110 dB
100 dB
90 dB
80 dB
70 dB
60 dB
50 dB
40 dB
20 dB
0 dB
Fig. 4
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