![background image](http://html1.mh-extra.com/html/shure/sm12a/sm12a_user-manual_1262137002.webp)
2
3. 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.
4. 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.)
5. Loosen the pivot adjustment knob and position the mi-
crophone as close as possible to the corner of the
mouth. For optimum close-talking operation, the micro-
phone 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) of the mouth to eliminate explo-
sive breath sounds (“pop”). Tighten the adjustment
knob.
6.. Snap the microphone connector belt clip over the
groove in the 3-pin 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 micro-
phone cable and the phone plug to the monitoring unit
cable.
MICROPHONE SPECIFICATIONS
TYPE
Dynamic, Close-Talking
FREQUENCY RESPONSE:
At 8 mm (5/16 in.)
50 to 15,000 Hz (see Figure 2)
POLAR PATTERN
Cardioid (unidirectional) response-uniform with frequen-
cy, symmetrical about axis (see Figure 3)
Impedance
Microphone rating impedance is 150 ohms (200 ohms ac-
tual) for connection to microphone inputs rated at 19 to
300 ohms
Sensitivity
(close-talked at 1,000 Hz)
Open Circuit Voltage
–67.0 dBV/Pa (.45 mV)
. . . . . . . . .
(1 Pa = 94 dB SPL)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hum Sensitivity
(typical)
38.4 dB equivalent SPL in a 1 millioersted field
Phasing
Positive pressure on diaphragm produces positive voltage
on pin 2 of microphone connector
Connector
Male XLR audio connector (TA3M)
Receiver
Type
Dynamic
Frequency Response
70 to 12,000 Hz
Impedance
2,000 ohms at 1 kHz (200-ohms cartridge with matching
transformer in phone plug)
Output Level
105 dB SPL with 1.4V at 1 kHz (1.0 mW into 2 cc cavity)
Phasing
Positive voltage on phone plug tip produces positive pres-
sure in ear tube
Connector
Phone plug (contains matching 200:2,000 ohm transformer)
GENERAL SPECIFICATIONS
Cable
Non-detachable, 1.5m (5 ft), four conductor, shielded,
plastic-jacketed; additional 762 mm (2.5 ft), two-conduc-
tor receiver cable attached to micorphone connector.
Case
Black thermoplastic microphone and pivot housing, anod-
ized aluminum end caps, stainless steel grille, ear tube
and boom
Dimensions
See Figure 4
Net Weight
84 grams (3 ounces) less cable and connectors
Packaged Weight
978 grams (2 lb, 2 1/2 oz)
CERTIFICATION
Eligible to bear CE Marking. Conforms to European EMC Di-
rective 89/336/EEC. Meets applicable tests and perfor-
mance criteria in European Standard EN55103 (1996) parts
1 and 2, for residential (E1) and light industrial (E2) environ-
ments.
ACCESSORIES AND REPLACEMENT PARTS
The following furnished accessories and replacement
parts may be ordered through your Authorized Shure Pro-
fessional Products Dealer or from Shure Incorporated.
Connector Belt Clip
RK200BC
. . . . . . . . . . . . . . . . . . . . .
Windscreen
RK 184WS
. . . . . . . . . . . . . . . . . . . . . . . . . .
Carrying Case
90DJ2600
. . . . . . . . . . . . . . . . . . . . . . . .
Microphone Cartridge
R93
. . . . . . . . . . . . . . . . . . . . . . . .
Receiver Cartridge
90EL2600
. . . . . . . . . . . . . . . . . . . . .
Headband Assembly
RK352
. . . . . . . . . . . . . . . . . . . . . .
Receiver Tip
90FS2600
. . . . . . . . . . . . . . . . . . . . . . . . . .