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

 

SHIELD =

 

Connector housing

3

PINS 3 and 4= BLACK

1

LEAD (jumped)

 

4

2

PIN 2 = RED LEAD

 

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

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)

 

 

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

2.0mA 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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Shure manual Microphone Specifications, Preamplifier Specifications MX391 and MX391 only, Furnished Accessories

MX391 specifications

The Shure MX391 is a modern solution for professional audio recording and communication in various settings. Ideal for conference rooms, boardrooms, and performance venues, the MX391 is designed to deliver high-quality audio capture while maintaining a low profile. This boundary microphone is engineered to pick up sound from all directions, making it perfect for capturing conversations around a table or ambient sounds in a room.

One of the standout features of the MX391 is its superior audio performance. It employs a cardioid pickup pattern, ensuring that it captures sound from the front while rejecting noise from the sides and rear. This design minimizes background noise and focuses on the primary audio source, making it an excellent choice for environments where multiple people are speaking or where ambient noise is a concern.

The MX391 is equipped with a built-in preamplifier, which ensures high sensitivity and a wide dynamic range. This preamplifier provides clean audio signals, allowing users to capture sound details without distortion. Additionally, the microphone features a frequency response range of 20 to 20,000 Hz, ensuring it captures a full spectrum of sound, from deep lows to clear highs.

Another technological advantage of the Shure MX391 is its low-profile design. The microphone can be discreetly mounted on a table or surface, minimizing visual distractions during presentations or discussions. It is available in different finishes to match the aesthetics of various environments, further enhancing its versatility.

The MX391 is also easy to install and integrate into existing audio systems. It can be connected to various Shure wireless systems or other professional audio equipment, thanks to its standard XLR output. This flexibility makes it a popular choice for audio professionals who require reliable and high-quality audio solutions.

Moreover, durability is a hallmark of the Shure brand, and the MX391 is no exception. It is constructed with high-quality materials designed to withstand the rigors of frequent use, ensuring long-lasting performance in demanding environments.

In summary, the Shure MX391 boundary microphone combines high sensitivity, cardioid pickup pattern, and low-profile design, making it an ideal choice for professional audio applications. Whether for corporate meetings, educational settings, or stage performances, the MX391 delivers exceptional sound quality and reliability, meeting the needs of audio professionals and users alike.