Audio-Technica unveils U851RO omnidirectional condenser boundary microphone

(Dave Molter | Posted 2011-02-19)

Audio-Technica unveils U851RO omnidirectional condenser boundary microphone

Just because you want a microphone to be hidden doesn't mean it doesn't have to sound good. Audio-Technica's new U851RO Omnidirectional Condenser Boundary Microphone features breakthrough audio and mechanical design innovations, and offersoutstanding speech intelligibility and transparent sound quality for surface-mount applications. Such applications include high-quality sound reinforcement, professional recording, television, conferencing and other demanding sound pickup situations.

The phantom-powered U851RO’s small-diameter UniPoint® capsule near the boundary eliminates phase distortion and delivers clear, high-output performance. The unit is equipped with a PivotPoint® rotating output connector, allowing the cable to exit from either the rear or the bottom of the microphone; a UniSteep® filter, which provides a steep low-frequency attenuation to improve sound pickup without affecting voice quality; and UniGuard® RFI-shielding technology, which offers outstanding rejection of radio frequency interference. Self-contained electronics eliminate the need for an external power module. It accepts interchangeable condenser elements in cardioid and hypercardioid polar patterns.

The U851RO features a low-profile design with a low-reflectance black finish for minimum visibility, in addition to a heavy die-cast case and silicon foam bottom pads to help minimize coupling of surface vibration to the microphone. The U851RO’s low-profile element provides a uniform omnidirectional polar pattern with a 360-degree acceptance angle.

U851RO Specifications

Element Fixed-charge back plate, permanently polarized condenser
Polar Pattern Omnidirectional in hemisphere above mounting surface
Frequency Response 30-20,000 Hz
Low Frequency Roll-Off 80 Hz, 18 dB/octave
Open Circuit Sensitivity -31 dB (28.2 mV) re 1V at 1 Pa
Impedance 200 ohms
Maximum Input Sound Level 132 dB SPL, 1 kHz at 1% T.H.D.
Dynamic Range (typical) 111 dB, 1 kHz at Max SPL
Signal-to-Noise Ratio 73 dB, 1 kHz at 1 Pa
Phantom Power Requirements 11-52V DC, 4 mA typical
Switch Flat, roll-off
Weight 9.2 oz (262 g)

4.25" (108.0 mm) maximum length
3.31" (84.0 mm) maximum width
0.91" (23.0 mm) maximum height

Output Connector TB3M-type
Cable 25' (7.6 m) long, 0.13" (3.2 mm) diameter, 2-conductor, shielded cable with TA3F-type and XLRM-type connectors
Optional Interchangeable Elements UE-C cardioid (120°); UE-H hypercardioid (100°)
Accessory Furnished Soft protective pouch

The U851RO Omnidirectional Condenser Boundary Microphone is currently available with a U.S. MSRP of $313.00. For more information, please visit

From a press release.

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