Audio Technica AT4055 Specifications

A T4055
HANDHELD CARDIOID
CAPACITOR MICROPHONE
Description
The AT4055 is a large-diaphragm, pressure-gradient capacitor
microphone with a uniform cardioid polar pattern. The frequency
response is smooth over an extended 20-20,000 Hz range. Based
on the same advanced technology used in 40 Series studio
microphones, the AT4055 is the result of a dedicated effort by
Audio-Technica to bring studio-quality sound to the stage. It is
designed for use in the most demanding sound reinforcement and
recording applications.
The AT4055 is the culmination of extensive field evaluations in
live-sound environments with resultant significant advances in
microphone performance factors. It features very low self-noise, with
a transformer-coupled output optimized for live-sound applications.
An extended, flat low-frequency response adds extra body and depth
to vocals, and highlights the performance of on-stage instruments.
The AT4055 incorporates a specially-contoured large diaphragm
that is aged through five different steps to assure the optimum
characteristics achieved will remain constant over years of use. The
2-micron-thick, vapor-deposited gold diaphragm provides extremely
smooth, warm and true-to-life reproduction of even the most subtle
sonic nuances.
The off-axis response of the AT4055 is linear and uniform across
the entire frequency range of the microphone. Any off-axis sounds
(leakage) remain accurate and lifelike, resulting in a much more
natural vocal/instrument mix.
For exceptional transient response and sound pressure level
capability, the element back plate is precision-milled and aged to
provide stable, optimum capacitance. The reductions in frequency
response peaks and diaphragm distortion result in a microphone
that delivers an articulate output even in very high sound pressure
environments.
To further enhance the on-stage performance capability,
Audio-Technica engineers have employed a carefully-designed shock-
mount system to provide outstanding handling noise characteristics
and mechanical shock resistance. In addition, the AT4055 element
is protected by a hardened-steel windscreen. For even greater dura-
bility and protection, the element is housed in a second, internal
windscreen, which also provides excellent resistance to popping.
The microphone element is enclosed in a rugged housing with
baked-on, low-reflectance black finish. The included AT8406 tapered
stand adapter permits mounting on any microphone stand with
5 / "-27 threads.
8
40 SERIES PRECISION MICROPHONES
Operation and Maintenance
Output is low impedance balanced. The output connector mates
with XLRF-type cable connectors. The balanced signal appears
across Pins 2 and 3 while the ground (shield) connection is Pin 1.
Output is phased so that positive acoustic pressure produces posi-
tive voltage at Pin 2 in accordance with industry convention.
The AT4055 will operate in conjunction with any remote "phan-
tom" or "simplex" power source supplying 48 volts DC. The phantom
voltage not only powers the microphone's impedance converter, but
is stepped-up to a higher voltage internally to polarize the capacitor
element.
While a modern capacitor microphone is not unduly sensitive to
the environment, temperature extremes can be harmful. Exposure
to high temperatures can result in gradual and permanent reduction
of the output level. Avoid leaving the microphone in the open sun or
in areas where temperatures exceed 110˚ F (43˚ C) for long periods
of time. Extremely high humidity should also be avoided.
Architects and Engineers Specifications
The microphone shall be an externally polarized DC bias
capacitor with a cardioid polar pattern and a frequency response of
20 Hz to 20,000 Hz. It shall operate from an external 48V DC ( 4V)
phantom power source.
Nominal open-circuit output voltage shall be 5.0 mV at 1 kHz,
1 Pascal. The microphone shall have an output impedance of
200 ohms and output shall be balanced. The microphone shall
accept a 147 dB SPL at 1 kHz while producing no greater than
1% T.H.D.
The microphone shall have a length of 6.97" (177.0 mm), a
maximum head diameter of 1.95" (49.5 mm), and a weight of
10.6 oz (300 grams). Finish shall be low-reflectance black.
The Audio-Technica AT4055 is specified.