40 series
microphones
AT4081
Bidirectional Active Ribbon Microphone
Features
• Smooth, warm and natural sound with precise, articulate detail
to meet the critical requirements of today’s recording, broadcast
and sound reinforcement professionals
• Groundbreaking Audio-Technica ribbon design with 18 patents
pending
• Proprietary MicroLinear
™
ribbon imprint for superior durability
and freedom from lateral flexing and distortion
• Innovative dual ribbon construction for increased sensitivity
• Extremely powerful N50 rare-earth neodymium magnets for high
output level
• Ultra-fine mesh helps protect against ribbon damage from wind
and plosives
• Classic bidirectional (figure-of-eight) polar pattern picks up
sounds equally from the front and back of the element
• High-SPL capability for exceptionally versatile performance
• Extended frequency response for natural audio reproduction
• Handmade production – including ribbon corrugation, imprint
and assembly
• Low-profile stick design maximizes placement options
• Phantom-powered active electronics provide stable impedance
and higher output for maximum compatibility with microphone
preamplifiers
Description
The AT4081 is a side-address active ribbon microphone with a
bidirectional polar pattern. Delivering the warmth and natural sound
of a classic ribbon microphone, the AT4081offers a robust build for
long-lasting performance and high gain for easy use with microphone
preamplifiers.
With 18 patents pending, Audio-Technica’s innovative ribbon transducer
advances the evolution of ribbon microphone technology, combining
remarkable durability and high-SPL capability with smooth, rich audio
quality. The microphone is recommended for horns, strings, acoustic
instruments, drum overheads, orchestras, ensembles and guitar cabinets.
It excels in recording studios as well as in live-sound settings.
A significant breakthrough in ribbon cartridge design, Audio-Technica’s
patent-pending MicroLinear
™
ribbon imprint minimizes ribbon distortion
for durable performance and accurate reproduction of the sound source.
While the application of phantom power was prohibited for old-
school ribbon microphones, Audio-Technica’s AT4081 requires 48V
phantom power for operation. The phantom power is used—not for the
microphone’s dynamic ribbon transducer—but for its active electronics,
which bring its output to near condenser microphone level. This high-
output and stable impedance make the microphone easy to integrate
with microphone preamplifiers.
The bidirectional polar pattern of the microphone makes it equally
sensitive to sounds originating in front and back of the element.
The output of the microphone is a 3-pin XLRM-type connector.
The microphone is enclosed in a rugged housing. The included AT8471
isolation clamp provides superior isolation and permits mounting on any
microphone stand with
5
/
8
"-27 threads. A windscreen and a protective
carrying case are also included.
Operation & Maintenance
The AT4081 requires 48V phantom power for operation.
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.
An Audio-Technica emblem is on the front of the microphone. Position this
side of the microphone toward the sound source.
Note: While Audio-Technica ribbon microphones designed for superior
durability, we recommend the following precautions when dealing with
ribbon microphones: do not blow directly into the ribbon assembly; use the
supplied windscreen for up-close vocal use.
Take care to keep foreign particles from entering the windscreen. An
accumulation of foreign material in the ribbon structure and/or the
windscreen’s mesh surface, can degrade performance. 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 Specifications
The microphone shall be an active ribbon microphone with a side-address
stick design. It shall have a bidirectional polar pattern and a frequency
response of 30 Hz to 18,000 Hz. The microphone shall operate from an
external 48V DC phantom power source. It shall be capable of handling
sound input levels up to 150 dB with a dynamic range of 125 dB. Nominal
open-circuit output voltage shall be 7.9 mV at 1V, 1 Pascal. Output shall
be low impedance balanced (100 ohms).
The output of the microphone shall be a 3-pin XLRM-type connector.
The microphone shall be 155.0 mm (6.10") long and have a body diameter
of 21.0 mm (0.83"). Weight shall be 152 g (5.4 oz). The microphone shall
include an isolation clamp, a windscreen and a protective carrying case.
The Audio-Technica AT4081 is specified.
