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U851RbO

Omnidirectional Condenser Boundary Microphone


U.S. Two-Year Limited End-User Warranty

*Manufacturer's Suggested Retail Price. Actual selling price may vary; please check with an authorized Audio-Technica dealer.

  • Omnidirectional Condenser Boundary Microphone
  • Omnidirectional Condenser Boundary Microphone


  • Overview
  • Features
  • Specifications
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  • Q & A

  • Overview


    The phantom-powered U851RbO omnidirectional condenser boundary microphone offers outstanding speech intelligibility and transparent sound quality for surface-mount applications such as high-quality sound reinforcement, professional recording, television, conferencing and other demanding sound pickup situations. The omnidirectional microphone is equipped with a PivotPoint® rotating output connector, UniSteep® filter and UniGuard® RFI-shielding technology. It accepts interchangeable condenser elements, available separately, in cardioid and hypercardioid polar patterns. With a heavy die-cast case and silicon foam bottom pads to minimize coupling of surface vibration to the microphone, the U851RbO is equipped with self-contained electronics, eliminating the need for an external power module. Threaded inserts on the bottom of the microphone allow it to be mounted with screws for increased security.
  • Features


    • Omnidirectional condenser boundary microphone

    • Designed for surface-mount applications such as high-quality sound reinforcement, professional recording, television, conferencing and other demanding sound pickup situations

    • Superior off-axis rejection for maximum gain before feedback

    • PivotPoint® rotating output connector allows cable to exit from either the rear or the bottom of the microphone

    • Small-diameter UniPoint® element near boundary eliminates phase distortion and delivers clear, high-output performance

    • Available interchangeable elements permit angle of acceptance from 100° to 360°

    • UniGuard® RFI-shielding technology offers outstanding rejection of radio frequency interference (RFI)

    • Self-contained electronics eliminate need for external power module

    • Heavy die-cast case and non-slip silicone foam bottom pads minimize coupling of surface vibration to the microphone

    • Low-profile design with low-reflectance finish for minimum visibility

    • Threaded inserts on bottom of microphone allow it to be mounted with screws for increased security

  • Specifications

    ELEMENTFixed-charge back plate, permanently polarized condenser
    POLAR PATTERNOmnidirectional
    FREQUENCY RESPONSE20-20,000 Hz
    LOW FREQUENCY ROLL-OFF80 Hz, 18 dB/octave
    OPEN CIRCUIT SENSITIVITY-31 dB (28.2 mV) re 1V at 1 Pa
    IMPEDANCE50 ohms
    MAXIMUM INPUT SOUND LEVEL132 dB SPL, 1 kHz at 1% T.H.D.
    DYNAMIC RANGE (typical)111 dB, 1 kHz at Max SPL
    SIGNAL-TO-NOISE RATIO73 dB, 1 kHz at 1 Pa, A-weighted
    PHANTOM POWER REQUIREMENTS11-52V DC, 4.4 mA
    SWITCHFlat, roll-off
    WEIGHT253 g (8.9 oz)
    DIMENSIONS0.91" (23.0 mm) H x 3.30" (83.9 mm) W x 4.25" (108.0 mm) D
    OUTPUT CONNECTORMicrophone: TB3M-type
    Cable: 3-pin XLRM-type
    CABLE25.0' (7.6 m) long, 0.13" (3.2 mm) diameter, 2-conductor, shielded cable with TA3F and XLRM connectors
    OPTIONAL INTERCHANGEABLE ELEMENTSUE-C cardioid (120°)
    UE-H hypercardioid (100°)
    ACCESSORY FURNISHEDSoft protective pouch



    Architect’s and Engineer’s Specifications

    The microphone shall be a fixed-charge condenser designed for use in surface-mount applications. It shall have an omnidirectional polar pattern in the hemisphere above the mounting surface and a frequency response of 20 Hz to 20,000 Hz. It shall be capable of accepting optional interchangeable elements for additional polar patterns. The microphone shall operate from an external 11V to 52V DC phantom power source. It shall be capable of handling sound input levels up to 132 dB with a dynamic range of 111 dB. Nominal open-circuit output voltage shall be 28.2 mV at 1V, 1 Pascal. Output shall be low impedance balanced (50 ohms). It shall offer outstanding rejection of radio frequency interference (RFI).

    The microphone shall incorporate self-contained electronics, eliminating the need for an external power module. A 7.6 m (25') miniature output cable with TA3F-type to XLRM-type connectors shall be supplied. The output of the microphone shall be a TB3M-type connector. The microphone shall include a switch to permit choice of flat response or 80 Hz low-frequency roll-off.

    The microphone shall be equipped with an integral rotating output connector that allows the cable to exit from either the rear or the bottom of the microphone without the need to disassemble the microphone or use tools to change the cable exit location.

    The microphone shall have a maximum width of 83.9 mm (3.30"), a maximum length of 108.0 mm (4.25") and a maximum height of 23.0 mm (0.91"). Weight shall be 253 grams (8.9 oz). The microphone shall be housed in a die-cast case with a perforated steel grille. Finish shall be low-reflectance black. The microphone shall include a soft protective pouch.

    The Audio-Technica U851RbO is specified.


    Conditions
  • Downloads

    U851RbO User Manual (pdf 626.66 KB)
    U851Rb & U891Rb Quick Start Guide (pdf 4.21 M)
  • Reviews

  • Q & A