Product Details


Equipped with features like programmable, silent membrane switches, logic inputs and outputs, and LED indicators, Microflex® Boundary Microphones are the high-quality solution for a range of applications such as altars, boardrooms and distance learning centers. Every Microflex Boundary microphone features a choice of interchangeable condenser cartridges.

MX391: Includes attached 4 meter (12 ft) cable terminated with a 4-pin mini connector and separate preamplifier. A rubber strain relief is provided for applications that require removing the 4-pin mini connector and connecting the mic cable directly to screw terminals in the preamplifier.


  • Flat frequency response across the vocal range for uncolored sound
  • Interchangeable cardioid, supercardioid, and omnidirectional cartridges that provide optimal choice for each application
  • Sleek, low-profile design for unobtrusive appearance
  • Balanced, transformerless output for increased immunity to noise over long cable runs
  • Programmable on/off switch and LED on/off indicator (MX392/MX393 models only)
  • LED logic input and switch logic output terminals for remote control or use with automatic mixers (MX392 models only)
Microphone Type
Frequency Response
Form Factor
Model Line

Available Options

MX391/C Cardioid, Black
MX391/S Supercardioid, Black
MX391/O Omnidirectional, Black
MX391W/C Cardioid, Off-White
MX391W/S Supercardioid, Off-White
MX391W/O Omnidirectional, Off-White
Polar Pattern Cardioid (MX391/C, MX391W/C) Supercardioid (MX391/S, MX391W/S) Omnidirectional (MX391/O, MX391W/O)
Frequency Response 50 to 17,000 Hz (Preamp Only)
lmpedance 180 ohms actual (rated at 150 ohms) (Preamp Only)
Output Level -6 dBV (0.5 V), 12 dB at 0 gain (Preamp Only)
Phantom power required? 11 to 52 Vdc phantom, 2.0 mA current consumption (Preamp Only)

Additional specifications are available in the user guide.


    R183 R183B and R183W Omnidirectional Cartridge

    Omnidirectional cartridge for all Microflex® MX183, MX202, MX391, MX392, MX393, MX405, MX410, MX415, MX412, MX418, and WL183 microphones. White or Black.

    from $39

    R184 R184B and R184W Supercardioid Cartridges

    Supercardioid cartridge for WL183, WL184, WL185 and all Microflex® MX183, MX202, MX391, MX392, MX393, MX405, MX410, MX415, MX412, and MX418 Microphones. White or Black.

    from $62

    R185 R185B and R185W Cardioid Cartridges

    Cardioid cartridge for all Microflex® MX185, MX202, MX391, MX392, MX393, MX405, MX410, MX415, MX412, MX418, and WL185 microphones. White or Black.

    from $55

    RK100PK In-Line Preamplifier

    In-Line Preamplifier for Microflex Microphones. Boosts resistance to Radio Frequency Interference (RFI).

    from $119

Software & Downloads


File Language Type File Size
Microflex Microphones Product Brochure English PDF 1.6 mb

CAD Drawings

File Language Type File Size
MX391 CAD Drawing English ZIP 6.35 kb

Specification Sheets

File Language Type File Size
MX391 Specification Sheet English PDF 1.59 mb

User Guides

File Language Type File Size
MX391 User Guide

Product Support

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