Cardioid Condenser Boundary Microphone

$499 + shipping (includes gst)

Featuring breakthrough audio and mechanical design innovations, the phantom-powered U851R offers outstanding speech intelligibility and transparent sound quality for surface-mount applications. The microphone is equipped with a PivotPoint® rotating output connector, UniSteep® filter and UniGuard® RFI-shielding technology. It accepts interchangeable condenser elements – available for boundary microphones in cardioid, hypercardioid and omnidirectional polar patterns. With a heavy die-cast case and silicon foam bottom pads to minimize coupling of surface vibration to the microphone, the U851R is equipped with self-contained electronics, eliminating the need for an external power module

  • Designed for surface-mount applications such as high-quality sound reinforcement, professional recording, television, conferencing and other demanding sound pickup situations
  • PivotPoint® rotating output connector allows cable to exit from either the rear or the bottom of the microphone
  • Superior off-axis rejection for maximum gain before feedback
  • UniGuard® RFI-shielding technology offers outstanding rejection of radio frequency interference (RFI)
  • Self-contained electronics eliminate need for external power module
  • Small-diameter UniPoint® capsule near boundary eliminates phase distortion and delivers clear, high-output performance
  • Heavy die-cast case and non-slip silicon foam bottom pads minimize coupling of surface vibration to the microphone
  • Low-profile design with low-reflectance finish for minimum visibility
  • Available in two colors: black (U851R) and white (U851RW)

Fixed-charge back plate, permanently polarized condenser

Polar Pattern

(cardioid in hemisphere above mounting surface)

Frequency Response

30-20,000 Hz

Low Frequency Roll-Off

80 Hz, 18 dB/octave

Open Circuit Sensitivity

–34 dB (19.9 mV) re 1V at 1 Pa


200 ohms

Maximum Input Sound Level

134 dB SPL, 1 kHz at 1% T.H.D.

Dynamic Range (Typical)

108 dB, 1 kHz at Max SPL

Signal-To-Noise Ratio

68 dB, 1 kHz at 1 Pa

Phantom Power Requirements

11-52V DC, 4 mA typical


Flat, roll-off


9.2 oz (262 g)


4.25″ (108.0 mm) long, 
3.31″ (84.0 mm) maximum width, 
0.91″ (23.0 mm) height

Output Connector



25.0′ (7.6 m) long, 0.13″ (3.2 mm) diameter, 2-conductor, shielded cable with TA3F and XLRM-type connectors

Optional Interchangeable Elements

UE-H hypercardioid (100°); 
UE-O omnidirectional (360°)

Accessories Furnished

Soft protective pouch

U851R/RW Submittal Sheet (PDF) Download
U851R/RW Spec Sheet (PDF) Download



Cardioid Condenser Boundary Microphone

$ 499

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