U891R boundary mic from Louis Grace, communications and electrical distributors

Audio Technica U 891R has been designed to deliver easy, flexible control in conference and boardroom installations, the versatile U891R cardioid condenser boundary microphone features a touch-sensitive on-off switch that can be set to three modes: press-on/press-off, press to talk, and press to mute. The phantom-powered microphone is equipped with a unique PivotPoint™ rotating output connector and an LED status indicator. UniGuard™ innovations offer unsurpassed immunity from radio frequency interference; interchangeable elements are available in cardioid, hypercardioid and omnidirectional polar patterns; an 80 Hz low-cut UniSteep® filter reduces pickup of low-frequency ambient noise. The microphone’s heavy die-cast case and silicon foam bottom pads minimize coupling of surface vibration to the microphone. The unit’s self-contained electronics eliminate the need for an external power module.

Ultra-quiet electronic switch can be set to any of three operating modes: “touch-on/ touch-off,” “touch-to-talk” and “touch-to-mute”
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)
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

Specifications:

ELEMENT:Fixed-charge back plate, permanently polarized condenser
POLAR PATTERN:Half-cardioid (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
IMPEDANCE: 200 ohms
MAXIMUM INPUT SOUND LEVEL:130 dB SPL, 1 kHz at 1% T.H.D.
DYNAMIC RANGE (typical):104 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
SWITCHES:Touch-sensitive control: on/off; Switch function: touch on/off, momentary on, momentary off; Flat, roll-off
WEIGHT:9.3 oz (264 g)
DIMENSIONS:4.25' (108.0 mm) long, 3.31' (84.0 mm) maximum width, 0.91' (23.0 mm) height
OUTPUT CONNECTOR:TB3M-type
CABLE: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°)
ACCESSORY FURNISHED:Soft protective pouch