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Cardioid Condenser Boundary Microphone with Local or Remote Switching

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.

  • Cardioid Condenser Boundary Microphone
  • Cardioid Condenser
  • Boundary Microphone
  • Remote Switching

  • Overview
  • Features
  • Specifications
  • Downloads

  • Overview

    A wide-range condenser microphone with a cardioid polar pattern, the U891RCb is equipped with local and remote switching options. Locally, the microphone’s touch-sensitive capacitive-type user switch can be set to three operating modes: touch-on/touch-off, press to talk, and press to mute. For enhanced control in conference and boardroom installations, the unit’s external contact closure capability allows a user to trigger an external device – a camera, for instance – from the microphone’s user switch. The phantom-powered mic is also equipped with an 80 Hz low-cut UniSteep® filter to reduce pickup of low-frequency ambient noise. Its two-state RGB LED status indicator can be controlled remotely. UniGuard® innovations offer unsurpassed immunity from radio frequency interference; additional interchangeable elements are available separately in hypercardioid and omnidirectional polar patterns; a unique PivotPoint® rotating connector changes the cable exit point – no tools required. The microphone’s heavy die-cast case and silicon foam bottom pads minimize coupling of surface vibration to the microphone, while threaded inserts on the bottom of the microphone allow it to be mounted with screws for increased security. The unit’s self-contained electronics eliminate the need for an external power module.
  • Features

    • Cardioid condenser boundary microphone with touch-sensitive capacitive-type user switch

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

    • Logic I/O capability permits control of remote devices from the microphone’s touch-sensitive capacitive-type user switch

    • The capacitive touch switch can be set to any of three operating modes: touch on/off, touch to talk and touch to mute

    • Integral, phantom-powered, two-state RGB LED indicator, which can be controlled locally or remotely, displays on/off status of microphone

    • 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
    LOW FREQUENCY ROLL-OFF80 Hz, 18 dB/octave
    OPEN CIRCUIT SENSITIVITY-34 dB (19.9 mV) re 1V at 1 Pa
    IMPEDANCE50 ohms
    DYNAMIC RANGE (typical)104 dB, 1 kHz at Max SPL
    SIGNAL-TO-NOISE RATIO68 dB, 1 kHz at 1 Pa, A-weighted
    SWITCHESActivation: on/off
    Switch function: touch on/off, momentary on, momentary off
    Control: local, remote, LED remote
    LED Color: mic on, mic off
    Flat, 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: Unterminated
    CABLE25.0' (7.6 m) long, 0.13" (3.2 mm) diameter, 5-conductor shielded cable (2 conductors under shield; 3 control wires outside shield); TA5F-type connector at microphone end, output end stripped and tinned for connection to electronic device
    UE-O omnidirectional (360°)
    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 a cardioid polar pattern with a uniform 120° angle of acceptance (cardioid in hemisphere above 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. It shall operate from an external 11V to 52V DC phantom power source. The microphone shall be capable of handling sound input levels up to 130 dB with a dynamic range of 104 dB. Nominal open-circuit output voltage shall be 19.9 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 feature an activation switch, a two-state RGB LED indicator, and an external contact closure output for controlling remote devices. The microphone shall offer three choices of switching modes: touch on/off, momentary on, momentary off. A three-position “Local/Remote/LED Remote” control function switch shall be provided on the microphone.

    The output of the microphone shall be a TB5M-type connector. A 7.6 m (25') miniature output cable with a TA5F-type connector at the microphone end shall be supplied. The output end of the cable shall have stripped and tinned color-coded leads for connections. 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 U891RCb is specified.

  • Downloads

    U891RCb User Manual (pdf 614.41 KB)
    U851Rb & U891Rb Quick Start Guide (pdf 4.21 M)