MICROPHONE SPECIFICATIONS
Polar Pattern (Figure 6)
Cardioid (MX391/C, MX391W/C)
Supercardioid (MX391/S, MX391W/S)
Omnidirectional (MX391/O, MX391W/O)
Environmental Requirements
Operating Temperature Range: -18° C to 57° C (0° F to 135° F)
Relative Humidity: 0 to 95%
Dimensions
See Figure 3.
Wiring Diagram
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1
4
2
PREAMPLIFIER SPECIFICATIONS:
MX391 AND MX391 ONLY
These specifications apply only to the MX391/MX391W microphones
when used with the supplied preamplifier. All measurements taken with
the microphone mounted on a 76.2 cm x 76.2 cm (30 in. x 30 in.) wood-
en surface and with the sound source incident at 30° with respect to
the surface plane.
Frequency Response (Figure 5)
50 to 17,000 Hz
Output Impedance (at 1000 Hz)
180Ω actual (rated at 150Ω)
Open Circuit Sensitivity
Cartridge Type
Cardioid
Supercardioid
Omnidirectional
All settings -12 dB at 0 gain
*1 Pascal = 94 dB SPL
SHIELD =
Connector housing
PINS 3 and 4= BLACK
LEAD (jumped)
PIN 2 = RED LEAD
FIGURE 2
1 kHz ref. 1 V per Pascal *
-29.6 dB (33.5 mV)
-28.3 dB (38.5 mV)
-21.5 dB (81.4 mV)
Maximum Sound Pressure Level
(1 kHz at 1% Total Harmonic Distortion, 1 kΩ load)
Cardioid: 118.8 dB
Supercardioid: 117.5 dB
Omnidirectional: 110.7 dB
All settings +6 dB at 0 gain
Signal to Noise Ratio (referenced at 94 dB SPL)
Cardioid: 71.4 dB
Supercardioid: 72.7 dB
Omnidirectional: 79.5 dB
Equivalent Output Noise (A-weighted)
Cardioid: 22.6 dB SPL
Supercardioid: 21.3 dB SPL
Omnidirectional: 14.5 dB SPL
Dynamic Range at 1 kΩ Load
96.2 dB
100 dB at 0 gain
Common Mode Rejection
45 dB minimum, 10 Hz to 100 kHz
Preamplifier Output Clipping Level
-6 dBV (0.5 V)
-12 dB at 0 gain
Polarity
Positive sound pressure on diaphragm produces positive voltage on pin
2 relative to pin 3 of the preamplifier XLR output connector.
Power Requirements
11 to 52 Vdc phantom
2.0 mA current consumption
Certification
Eligible to bear CE Marking. Conforms to European EMC Directive 89/
336/EEC. Meets applicable tests and performance criteria in European
Standard EN55103 (1996) parts 1 and 2, for residential (E1) and light
industrial (E2) environments.
FURNISHED ACCESSORIES
Zipper Bag.......................................................................... 95A2313
In-Line Preamp (MX391 & MX391W)................................RK100PK
Hex Wrench #4 (MX391 & MX391 W) ................................... 80A67
REPLACEMENT PARTS
Omnidirectional Cartridge ..................................................... R183B
Supercardioid Cartridge ........................................................ R184B
Cardioid Cartridge ................................................................. R185B
In-Line Preamplifier (black) ...............................................RK100PK
In-Line Preamplifier (white) ........................................... RK100PKW
NOTE: For technical data by Fax, phone 1-800-516-2525 and follow the
recorded instructions. For additional technical assistance, phone Shure at
(847) 600-2000. In Europe, phone 49-7131-72140.
SHURE, the Shure logo, and MICROFLEX are registered trademarks of
Shure Incorporated.
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