Shure SM12 User Guide
GENERAL
The Shure Model SM12 Professional Head-Worn Microphone with Receiver is a low-impedance, unidirectional, dynamic microphone with an integral earphone
assembly. Designed for sports and news announcing,
interviewing and intercommunication systems, and for
special-events remote
broadcasting, the SM12 offers
convenient, hands-free operation without user fatigue.
A
close-talking unit, the SM12 may be used under
noisy conditions without loss or masking of voice
signals. The SM12 is a small, lightweight, rugged and
reliable unit, with provisions for mounting to a supplied
A
cushioned headband.
microphone boom to be moved
pivot housing permits the
20" in any direction,
and the distance between the microphone and pivot
3%
to be changed by up to
inches. The receiver ear
tube, attached to the bottom of the pivot housing, may
55"
be moved through a
arc. A miniature windscreen
to protect against wind noise and explosive breath
sounds, and two connector belt clips are also supplied.
Model
=
SM12
Features:
Close-talk operation and unidirectional polar pattern for effective noise reduction
Smooth natural voice frequency response
Locking adjustment knob permits boom to pivot 20"
in any direction
Boom length adjustment through
Receiver ear tube adjustable through
3%
inch range
55"
arc
Light weight plus padded headband eliminate user
fatigue
Does not interfere with eyeglasses
Ruggedly constructed of stainless steel, aluminum
and high-impact thermoplastic
Convenient, secure clips attach connectors to belt
or clothing
PRODUCTS
DATA
ASSEMBLY
Assemble the SM12 for use as follows:
Twist the lower headband arms 90" so they are
perpendicular to the headband. The headband pads
must be located toward the rear of the
user:s head.
For left side usage, the retaining clip will be on
the left side of the user's head; for right side us-
age, the clip will be on the right (see photo'and
Figure 1). Swivel the retaining clip forward (top of
clip away from the headband) until it snaps into
position.
2. Snap the microphone pivot housing into the retaining clip with the pivot adjustment knob upward
and the microphone toward the front. (Note that
the microphone position-left or right side-may
be reversed by twisting the headband arms
180°,
swiveling the retaining clip 90°, and repositioning
the pivot housing.) Loosen the pivot adjustment
knob, position the boom so that the microphone is
near where the side of the mouth will be, and
tighten the pivot adjustment knob.
3.
Place the assembled microphone on the user's
head and pull the headband arms downward until
they rest against the head just over the ears.
Position the receiver tip at the entrance to the ear.
(Make certain cable is free of receiver ear tube.)
HEADBA
ARM
SM12
POSITIONED
ADJUSTMENT
FOR
LEFT SIDE
FIGURE
OPERATION
1
Copyright
27A1326
1980,
(TB)
Shure
Brothers
Inc.
U.S.
Patent
Printed in
4,039,765
U.S.A.
WARNING
Sustained high volume levels in conjunction with
a tightly fitting receiver tip may adversely affect
the user's hearing. Make certain the volume is set
to a comfortable listening level and position the
receiver tip at the entrance of the ear.
4. Loosen the pivot adjustment knob and position the
microphone as close as possible to the corner of
the mouth. For optimum close-talking operation,
the microphone should be less than 25 mm (1 in.)
from the corner of the mouth. Be sure to position
the microphone at the corner (not the center)
the mouth to eliminate explosive breath sounds
("pop"). Tighten the adjustment knob.
5.
Snap the microphone connector belt clip over the
groove in the 3-pin male audio connector and the
receiver connector belt clip over the groove in the
phone plug. The clips can now be fastened to the
user's belt or other clothing. Attach the 3-pin audio
connector to the microphone cable and the phone
plug to the monitoring unit cable.
A
6. NOTE:
decrease in receiver output may be due
to clogging of the receiver tip. The tip may be
cleaned by removing it from the ear tube and
inserting a toothpick or similar device through the
tip hole. If clogging is apparent in the ear tube,
carefully remove the obstruction from the ear tube
tip.
CAUTION:
Do not disturb the foam damping
material located just inside the ear tube tip.
of
lmpedance
Microphone rating impedance is 150 ohms (200 ohms
actual) for connection to microphone inputs rated
at 19 to 300 ohms
Output Level (close-talked at 1,000 Hz)
Open Circuit Voltage
. . .
. .
.
. .
-47.0
dB (4.5
(0 dB = 1 volt per 100 microbars)
Power Level
. . . . .
. . .
. .
. . . .
.
-66.0 dB
(0 dB = 1 milliwatt per 10 microbars)
Hum Sensitivity (typical)
38.4 dB equivalent SPL
ln a 1 millioersted field
Phasing
Positive pressure on diaphragm produces positive
voltage on pin 2 of microphone connector
Connector
Professional three-pin male audio connector designed to mate with Cannon XL series, Switchcraft
(Q.G.)
A3
series or equivalent connectors.
RECEIVER
Type
Dynamic
Frequency Response
70 to 12,000 Hz
mV)
SPECIFICATIONS
MICROPHONE
Type
Dynamic, Close-Talking
Frequency Response (at 8 mm 15/16 in.])
50 to 15,000 Hz (see Figure 2)
+,o
!o
5
-40
Im
FREOITIICV
IN
HERTZ
TYPICAL
Polar Pattern
Cardioid (unidirectional) response-uniform with frequency, symmetrical about axis (see Figure 3)
MICROPHONE
FIGURE
FREQUENCY
2
RESPONSE
lmpedance
2,000 ohms at 1 kHz (200-ohm cartridge with match-
ing transformer in phone plug)
Output Level
105 dB SPL with
1.414V at 1 kHz (1.0
mW
into 2 cc
cavity)
Phasing
Positive voltage on phone plug tip produces positive
pressure in ear tube
Connector
Phone Plug (contains matching
200:2,000 ohm trans-
former)
GENERAL
Cable
Non-detachable,
1.5m (5 ft), four-conductor, shielded,
plastic-jacketed; additional 762 mm (2.5 ft), two-conductor receiver cable attached to microphone connector
Case
Black thermoplastic microphone and pivot housing,
anodized aluminum end caps, stainless steel grille,
ear tube and boom
LEGEND
. . .
.
. . .
POLAR
FIGURE
4000
Hz
PATTERN
3
Dimensions
See Figure
4
Net Weight
84 grams (3 ounces) less cable and connectors
Packaged Weight
797 grams
(1
Ib, 12 oz)
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