Audio-Technica AT831b Dépliant

SCALE IS 5 DECIBELS PER DIVISION

200 Hz

LEGEND

5 kHz

1 kHz

8 kHz

12" or more on axis

LEGEND

Roll-off

Frequency in Hertz

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.

Battery installation: Remove the cap from the top of the power 
module. Inser t 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.

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.

Fixed-charge back plate 
permanently polarized 
condenser

Cardioid

40-18,000 Hz

80 Hz, 18 dB/octave

–44 dB (6.3 mV) /

(Phantom / Battery)

–46 dB (5.0 mV) re 1V at 1 Pa*

IMPEDANCE (Phantom / Battery)

200 ohms / 270 ohms

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

65 dB, 1 kHz at 1 Pa*

11-52V DC, 2 mA typical

1.5V AA/UM3 

0.4 mA / 1200 hours typical 
(alkaline)

Off, on-flat, on-roll-off

WEIGHT (less cable and accessories)

2.8 g (0.1 oz)

139 g (4.9 oz)

25.0 mm (0.98") long, 
10.2 mm (0.40") diameter

84.0 mm (3.31") H x 
63.0 mm (2.48") W x 
22.0 mm (0.87") D 

Integral 3-pin XLRM-type

(power module) 

1.8 m (6') long (permanently 
attached to microphone), 
2.6 mm ( 0.10") diameter, 
2-conductor, shielded cable 
with TA3F-type connector 

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.