Audio-Technica AT831b - 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

Audio -Technica U.S., Inc.,

1221 Commerce Drive, Stow, Ohio 44224

Audio -Technica Limited,

Old Lane, Leeds LS11 8AG England

www.audio-technica.com

P51967 ©2007 Audio -Technica U.S., Inc. Printed in Japan

• 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.

Batter y installation: Remove the cap from the top of the power
m o d u l e. I n s e r t a f r e s h 1 . 5 V A A b a t t e r y ( “ + ” e n d t owa r d t h e
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.

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
t e m p e r a t u r e s ex c e e d 1 1 0 ° F ( 4 3 ° C ) fo r ex t e n d e d p e r i o d s .
Extremely high humidity should also be avoided.

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

1

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

2

= 10 microbars = 94 dB SPL

1

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

Specifications are subject to change without notice.

AT831b

MINIATURE CARDIOID
CONDENSER MICROPHONE