2
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
FIGURE 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
All settings -12 dB at 0 gain
*1 Pascal = 94 dB SPL
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.
Cartridge Type 1 kHz ref. 1 V per Pascal *
Cardioid -29.6 dB (33.5 mV)
Supercardioid -28.3 dB (38.5 mV)
Omnidirectional -21.5 dB (81.4 mV)
4
3
1
2
SHIELD =
Connector housing
PINS 3 and 4= BLACK
LEAD (jumped)
PIN 2 = RED LEAD