Shure MX391/C Microflex Boundary Microphone

There's never been smarter boundary microphones than the Microflex models from Shure. With many models to choose from, 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 centres. Every Microflex Boundary microphone features one of the new interchangeable condenser cartridges. Available in cardioid, supercardioid and omnidirectional polar patterns, the Microflex cartridges give you superior Shure quality sound options for every installation. In addition, their programmable switches offer the flexibility to be set for Push to Talk, Push to Mute or Push On/Push Off modes. Attractively designed with a low profile, professional appearance, the Microflex Boundary microphones come with an easy to use paint mask for your custom-colour installations.

MX391/C (Cardioid) Miniature Black Condenser Boundary Microphone, In-Line Preamp, 12 foot (4 meter) Attached Cable to 4-Pin Mini Connector (TA4F)

Specifications:

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.) wooden surface and with the sound source incident at 30 degrees with respect to the surface plane.

• Frequency Response: 50 to 17,000 Hz
• Output Impedance (at 1000 Hz): 180 Ohms actual (rated at 150 Ohms)
• 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 k Ohm 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 k Ohm 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
• PolarityPositive 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

dv247.com model guide:

Miniature Black Condenser Boundary Microphone, In-Line Preamp, 12 foot (4 meter) Attached Cable to 4-Pin Mini Connector (TA4F) - Models: MX391/C (Cadioid), MX391/S (Supercardioid), MX391/O (Omnidirectional)

Miniature Black Condenser Boundary Microphone, 12-foot (3.6 m) Attached Cable to 4-Pin Mini Connector (TA4F), MX1BP Preamplifier - Models: MX391BP/C (Cardioid), MX391BP/S (Supercardioid), MX391BP/O (Omnidirectional)

Miniature Black Condenser Boundary Microphone (Wireless Compatible), 12-foot (3.6 m) Attached Cable to 4-Pin Mini Connector, Less Preamplifier - Models: MX391LP/C (Cardioid), MX391LP/S (Supercardioid), MX391LP/O (Omnidirectional)

Miniature White Condenser (Wireless Compatible) Boundary Microphone, 12 foot Attached Cable to 4-Pin Mini Connector, Less Preamplifier - Models: MX391WLP/C (Cardioid), MX391WLP/S (Supercardioid), MX391WLP/O (Omnidirectional)

Miniature White Condenser Boundary Microphone, 12 foot (3.6 m) Attached Cable to 4-Pin Mini Connector (TA4F), In-Line Preamplifier - Models: MX391W/C (Cardioid), MX391W/S (Supercardioid), MX391W/O (Omnidirectional)

Condenser Boundary Microphone, Built-in Preamp, Attached 12 foot (3.6 m) Unterminated Cable, Logic Functions, Programmable Switch and LED Indicator - Models: MX392/C (Cardioid), MX392/S (Supercardioid), MX392/O (Omnidirectional)

Condenser Boundary Microphone, Built-in Preamp, 12-foot (3.6m) 3-Pin Mini Connector (TA3F) to male XLR, Programmable Switch and LED Indicator - Models: MX393/C (Cardioid), MX393/S (Supercardioid), MX393/O (Omnidirectional)