Audio-Technica AT831b Cardioid Condenser Lavalier Microphone

The AT831b is a miniature clip-on/lavalier condenser microphone designed for quality sound reinforcement, professional recording, television, and other demanding sound pickup applications. It offers a cardioid polar pattern for excellent sound isolation.

Features

• Clip-on lavalier microphone providing crisp, full-sounding voice pickup.
• Also suitable as an instrument microphone, particularly for acoustic guitar with the 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 the desired sound source.
• Offers the convenience of battery or phantom power operation.
• Rugged design and construction for reliable performance.
• UniSteep® filter provides 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 clothing or used as an instrument mic for excellent yet unobtrusive sound pickup. Its wide-range capability ensures clean, accurate reproduction with high intelligibility for speakers and presenters, as well as for instrument pickup. Its small size makes it ideal for applications where minimum visibility is required.

The microphone requires 11 V to 52 V phantom power or a 1.5 V 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. It 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/flat response, or on/low-roll-off (via integral 80 Hz high-pass UniSteep® filter). 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 11 V to 52 V phantom power or a 1.5 V 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 1.5 V 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/flat response, or on/low-roll-off (via integral 80 Hz high-pass UniSteep® filter). 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. To engage the UniSteep® filter, slide the switch toward the "bent" line. To turn the microphone on without engaging the UniSteep® filter, slide the switch toward the flat 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.

Specifications

¹ Pascal = 10 dynes/cm² = 10 microbars = 94 dB SPL

¹ Typical, A-weighted, using Audio Precision System One. Specifications are subject to change without notice.

Frequency Response and Polar Pattern

The document includes a graph illustrating the frequency response of the AT831b microphone, showing a range from 40 Hz to 16,000 Hz. It also displays a polar pattern diagram indicating the microphone's directional sensitivity at different frequencies (200 Hz, 1 kHz, 5 kHz, 8 kHz).

For environmental reasons, product information is available online at www.audio-technica.com in multiple languages.