Audio-Technica AT831b User Manual

SCALE IS 5 DECIBELS PER DIVISION

Polar Pattern

200 Hz

LEGEND

5 kHz

1 kHz

8 kHz

12" or more on axis

LEGEND

Roll-off

Frequency in Hertz

Frequency Response

Response in dB

AT831b

MINIATURE CARDIOID CONDENSER MICROPHONE

• Clip-on lavalier mic provides crisp, full-sounding voice pickup

• Also excels as an instrument mic, especially for pickup of acoustic guitar with included AT8444 instrument adapter

• Excellent gain before feedback and suppression of background noise

• UniSteep

filter provides a steep low-frequency attenuation to

improve sound pickup without affecting voice quality

• Operates on battery or phantom power

For use as a lavalier, attach the microphone about six inches below the chin. Anticipate movements that may cause the microphone to rub against or be covered by clothing, and position the microphone to avoid it.

The AT831b requires 11-52V DC phantom power,

or a 1.5V AA battery for operation. A battery need not be in place for phantom power operation.

Battery installation: Remove the cap from the top of the power module. Insert a fresh 1.5V AA battery (“+” end toward the cap release button), then reassemble the power module. Alkaline batteries are recommended for longest life. Remove the battery during long-term storage.

Output from the power module’s XLRM-type connector 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.

To avoid phase cancellation and poor sound, all mic cables must be wired consistently: Pin 1-to-Pin 1, etc.

An integral 80 Hz high-pass UniSteep

filter provides easy switching from a flat frequency response to a low-end roll-off. The roll-off position reduces the microphone’s sensitivity to popping in close vocal use. It also reduces the pickup of low-frequency ambient noise (such as traffic, air-handling systems, etc.), room reverberation and mechanically coupled vibrations.

AT831b SPECIFICATIONS

†

ELEMENT Fixed-charge back plate

permanently polarized condenser

POLAR PATTERN Cardioid

FREQUENCY RESPONSE 40-18,000 Hz

LOW FREQUENCY ROLL-OFF 80 Hz, 18 dB/octave

OPEN CIRCUIT SENSITIVITY –44 dB (6.3 mV) /

(Phantom / Battery) –46 dB (5.0 mV) re 1V at 1 Pa*

IMPEDANCE (Phantom / Battery) 200 ohms / 270 ohms

MAXIMUM INPUT SOUND LEVEL 135 dB / 121 dB SPL,

(Phantom / Battery) 1 kHz at 1% T.H.D.

DYNAMIC RANGE (typical) 106 dB / 92 dB, (Phantom / Battery) 1 kHz at Max SPL

SIGNAL-TO-NOISE RATIO

65 dB, 1 kHz at 1 Pa*

PHANTOM POWER 11-52V DC, 2 mA typical REQUIREMENTS

BATTERY TYPE 1.5V AA/UM3

BATTERY CURRENT / LIFE 0.4 mA / 1200 hours typical

(alkaline)

SWITCH Off, on-flat, on-roll-off

WEIGHT (less cable and accessories)

MICROPHONE 2.8 g (0.1 oz) POWER MODULE 139 g (4.9 oz)

DIMENSIONS

MICROPHONE 25.0 mm (0.98") long,

10.2 mm (0.40") diameter

POWER MODULE 84.0 mm (3.31") H x

63.0 mm (2.48") W x

22.0 mm (0.87") D

OUTPUT CONNECTOR Integral 3-pin XLRM-type (power module)

CABLE 1.8 m (6') long (permanently

attached to microphone),

2.6 mm ( 0.10") diameter, 2-conductor, shielded cable with TA3F-type connector

ACCESSORIES FURNISHED AT8531 power module;

AT8417 clothing clip; AT8444 instrument adapter; AT8116 windscreen; battery; protective carrying case

†

In the interest of standards development, A.T.U.S. offers full details on its test methods to other industry professionals on request.

*1 Pascal = 10 dynes /cm

Typical, A-weighted, using Audio Precision System One.

Specifications are subject to change without notice.

= 10 microbars = 94 dB SPL

The microphone is RoHS compliant–free from all substances specified in the EU directive on hazardous substances.

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.

Audio-Technica U.S., Inc., 1221 Commerce Drive, Stow, Ohio 44224

Audio-Technica Limited, Old Lane, Leeds LS11 8AG England

www.audio-technica.com