Audio Technica AT8351 Manual

broadcast & production microphones
AT831b
Cardioid Condenser Lavalier Microphone
Features
• 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
• Cardioid polar pattern reduces pickup of sounds from the sides
and rear, improving isolation of desired sound source
• Offers the convenience of battery or phantom power operation
• Rugged design and construction for reliable performance
• UniSteep® lter provides a steep low-frequency attenuation to
improve sound pickup without affecting voice quality
Description
The AT831b is a miniature clip-on/lavalier condenser microphone with
a cardioid polar pattern. It is designed for quality sound reinforcement,
professional recording, television and other demanding sound pickup
applications.
The microphone is intended to be worn on the clothing or used as an
instrument mic for excellent yet unobtrusive sound pickup. The wide-
range capability of the microphone ensures clean, accurate reproduction
with high intelligibility for speakers and presenters as well as for
instrument pickup. Its small size makes it ideal for use in applications
where minimum visibility is required.
The microphone requires 11V to 52V phantom power or a 1.5V AA battery
for operation. A battery need not be in place for phantom power operation.
The microphone’s cardioid polar pattern provides a 120° angle of
acceptance.
The microphone includes a 1.8 m (6') permanently attached miniature
cable. Its free end connects to the provided AT8531 power module via a
TA3F-type connector. The output of the power module is a 3-pin XLRM-
type connector.
A 3-position switch in the power module permits choice of off, on/at
response or on/low-roll-off (via integral 80 Hz high-pass UniSteep® lter).
The roll-off position reduces the pickup of low-frequency ambient noise.
The microphone comes equipped with a power module, a clothing clip, an
instrument adapter, a windscreen, a battery and a protective carrying case.
Operation and Maintenance
The AT831b requires 11V to 52V phantom power or a 1.5V AA battery for
operation. A battery need not be in place for phantom power operation.
To install the battery, 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. For longest battery life, the switch
should remain off except when the microphone is in use. Alkaline
batteries are recommended for longest life. Remove the battery during
long-term storage.
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.
To avoid phase cancellation and poor sound, all mic cables must be wired
consistently: Pin 1-to-Pin 1, etc.
A 3-position switch in the power module permits choice of off, on/at
response, or on/low-roll-off (via integral 80 Hz high-pass UniSteep® lter).
The roll-off position reduces the microphones sensitivity to popping in
close vocal use. It also reduces the pickup of low-frequency ambient
noise (such as trafc, air-handling systems, etc.), room reverberation and
mechanically coupled vibrations. To engage the UniSteep® lter, slide
the switch toward the “bent” line. To turn the microphone on without
engaging the UniSteep® lter, slide the switch toward the at line.
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.
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.
Architect’s and Engineer’s Specications
The microphone shall be a xed-charge condenser. It shall have a cardioid
polar pattern with a uniform 120° angle of acceptance and a frequency
response of 40 Hz to 18,000 Hz. The microphone shall operate from an
external 11V to 52V DC phantom power source or, alternatively, from a
1.5V AA/UM3 battery. It shall be capable of handling sound input levels
up to 135 dB (phantom) or 121 dB (battery) with a dynamic range of
106 dB (phantom) or 92 dB (battery). Nominal open-circuit output voltage
shall be 6.3 mV (phantom) or 5.0 mV (battery) at 1 V, 1 Pascal. Output
shall be low impedance balanced (200 ohms – phantom, 270 ohms –
battery).
The microphone shall have a 1.8 m (6') permanently attached miniature
cable terminating in a TA3F-type output connector. The output connector
shall connect to a TB3M-type jack on the included power module. The
power module shall house the battery, and shall contain a switch that
permits choice of off, on/at response or on/low-roll-off (80 Hz). The
output of the power module shall be a 3-pin XLRM-type connector.
The microphone shall be 25.0 mm (0.98") long and have a diameter of
10.2 mm (0.40"). Weight shall be 2.8 grams (0.1 oz). The microphone
shall include a power module, a clothing clip, an instrument adapter,
a windscreen, a battery and a protective carrying case. Finish shall be
low-reectance black.
The Audio-Technica AT831b is specied.
AT 8351
AT8351
AT 8351
AT8531
AT8531

AT831b
Audio-Technica U.S., Inc., 1221 Commerce Drive, Stow, Ohio 44224
Audio-Technica Limited, Old Lane, Leeds LS11 8AG England
©2010 Audio-Technica U.S., Inc. audio-technica.com 0001-0183-01
Specications
LEGEND
200 Hz
1 kHz
5 kHz
8 kHz
SCALE IS 5 DECIBELS PER DIVISION
240˚
180˚
210˚
270˚
300˚
330˚ 0˚
150˚
120˚
90˚
30˚
60˚
12" or more on axis
LEGEND
Frequency in Hertz
Response in dB
10 dB
100
50 200 10k 5k
1k
500 2k 20k
Roll-off
frequency response: 40–16,000 Hz
polar pattern
Fixed-charge back plate, permanently
polarized condenser
Cardioid
40-18,000 Hz
80 Hz, 18 dB/octave
Phantom: –44 dB (6.3 mV) re 1V at 1 Pa
Battery: –46 dB (5.0 mV) re 1V at 1 Pa
Phantom: 200 ohms
Battery: 270 ohms
Phantom: 135 dB SPL, 1 kHz at 1% T.H.D.
Battery: 121 dB SPL, 1 kHz at 1% T.H.D.
Phantom: 106 dB, 1 kHz at Max SPL
Battery: 92 dB, 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-at, on-roll-off
Microphone: 2.8 g (0.1 oz)
Power module: 139 g (4.9 oz)
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
Power module: Integral 3-pin XLRM-type
1.8 m (6') long (permanently attached to
microphone), 2.6 mm (0.10") diameter,
2-conductor, shielded cable with TA3F-
type connector
M1
AT8531 power module; AT8419 clothing
clip; AT8444 instrument adapter; AT8116
windscreen; battery; protective carrying
case
Element
Polar pattern
Frequency response
Low frequency roll-off
Open circuit sensitivity
Impedance
Maximum input sound level
Dynamic range (typical)
Signal-to-noise ratio1
Phantom power requirements
Battery type
Battery current / life
Switch
Weight
Dimensions
Output connector
Cable
Audio-Technica case style
Accessories furnished
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/cm2 = 10 microbars = 94 dB SPL
1 Typical, A-weighted, using Audio Precision System One.
Specications are subject to change without notice.
405
AT 8351
AT8531