Audio-Technica U851RO User Manual

U851RO

Omnidirectional Condenser Boundary Microphone

Features

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

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

• 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

• UniSteep® lter provides a steep low-frequency attenuation to improve sound pickup without affecting voice quality

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

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

• Low-prole design with low-reectance nish for minimum visibility

unipoint® microphones

The microphone's heavy die-cast case and non-slip silicon foam bottom pads minimize coupling of surface vibration to the microphone. The microphone includes a soft protective pouch and features a lowreectance black nish.

Installation and Operation

The U851RO requires 11V to 52V phantom power for operation.

Output is low impedance (Lo-Z) balanced. The signal appears across Pins 2 and 3; Pin 1 is ground (shield). Output phase is “Pin 2 hot”— positive acoustic pressure produces positive voltage at Pin 2.

The microphone should be placed on a at, unobstructed mounting surface. The sound source should not be below the plane of the mounting surface.

An integral 80 Hz high-pass UniSteep® lter provides easy switching from a at frequency response to a low-end roll-off. The roll-off position reduces the pickup of low-frequency ambient noise (such as trafc, airhandling systems, etc.), room reverberation and mechanically coupled vibrations. To engage the UniSteep® lter, slide the switch toward the “bent” line.

The microphone’s PivotPoint® rotating output connector allows the cable to exit from either the rear or the bottom of the microphone without the need for tools or disassembly.

Avoid leaving the microphone in the open sun or in areas where temperatures exceed 110° F (43° C) for extended periods. Extremely high humidity should also be avoided.

Note: Audio-Technica has developed a special RFI-shielding mechanism, which is an integral part of the connectors in the UniPoint® line. If you remove or replace the connector, you may adversely affect the unit's RFI immunity. Audio -Technica offers a crimp tool (ATCT) and RFI shields that enable you to shorten the cable and correctly reinstall the connector while maintaining the highest level of RFI immunity.

U851RO Description

The U851RO is a wide-range condenser microphone with an omnidirectional polar pattern. It is designed for surface-mount applications such as high-quality sound reinforcement, conferencing, professional recording, television and other demanding sound pickup applications.

The microphone requires 11V to 52V phantom power for operation.

The microphone is equipped with UniGuard® RFI-shielding technology, which offers outstanding rejection of radio frequency interference (RFI).

The microphone’s omnidirectional polar pattern provides a 360° angle of acceptance (omni in hemisphere above mounting surface). Additional interchangeable elements with cardioid (120°) and hypercardioid (100°) pickup patterns are available.

The microphone includes a 7.6 m (25') output cable terminating in special TA3F-type and XLRM-type connectors designed to optimize RFI immunity. The output of the microphone is a TB3M-type connector. The microphone is equipped with Audio-Technica's unique PivotPoint® rotating output connector.

A switch permits choice of at response or low-frequency roll-off (via integral 80 Hz high-pass UniSteep® lter) to help control undesired ambient noise.

Note: Placing any object on a surface (such as a conference table) before its nish is fully cured may result in damage to the nish.

Architect’s and Engineer’s Specications

The microphone shall be a xed-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 30 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 (200 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 at response or 80 Hz lowfrequency 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.

U851RO

The microphone shall have a maximum width of 84.0 mm (3.31"), a maximum length of 108.0 mm (4.25") and a maximum height of 23.0 mm (0.91"). Weight shall be 262 grams (9.2 oz). The microphone shall be housed in a die-cast case with a perforated steel grille. Finish shall be low-reectance black. The microphone shall include a soft protective pouch.

The Audio-Technica U851RO is specied.

Specications

Element

Polar pattern

Frequency response

Low frequency roll-off

Open circuit sensitivity

Impedance

Maximum input sound level

Dynamic range (typical)

Signal-to-noise ratio

Phantom power requirements

Switch Weight

Dimensions

Output connector

Cable

Optional interchangeable elements

Accessory furnished

In the intere st of standards develo pment, A.T.U.S. offers full

details on it s test methods to othe r industry

1 Pascal = 10 dynes/cm

Typical, A-weighted , using Audio Precisio n System One.

Specications are subject to change without notice.

professionals on request.

= 10 microba rs = 94 dB SPL

Fixed-charge back plate, permanently polarized condenser Omnidirectional in hemisphere above mounting surface 30-20,000 Hz 80 Hz, 18 dB/octave –31 dB (28.2 mV) re 1V at 1 Pa 200 ohms 132 dB SPL, 1 kHz at 1% T.H.D. 111 dB, 1 kHz at Max SPL

73 dB, 1 kHz at 1 Pa 11-52V DC, 4 mA typical Flat, roll-off 262 g (9.2 oz)

108.0 mm (4.25") maximum length,

84.0 mm (3.31") maximum width,

23.0 mm (0.91") maximum height TB3M-type

7.6 m (25.0') long, 3.2 mm (0.13") diameter, 2-conductor, shielded cable with TA3F-type and XLRM-type connectors UE-C cardioid (120°) UE-H hypercardioid (100°) Soft protective pouch

frequency response: 30–20,000 Hz

10 dB

100

12" or more on axis Roll-off

330˚

200

Frequency in Hertz

0˚

180˚

500

30˚

150˚

60˚

120˚

10k

90˚

LEGEND

200 Hz

1 kHz 5 kHz 8 kHz

LEGEND

polar pattern

300˚

270˚

240˚

210˚

SCALE IS 5 DECIBELS PER DIVISION

Response in dB

20k