Audio Technica AT4055 Specifications

AT4055

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 v ery 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 e xtremely
smooth, warm and true-to-life reproduction of even the most subtle
sonic nuances.

The off-axis response of the A T4055 is linear and unif orm 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 shock­mount system to provide outstanding handling noise characteristics
and mechanical shock resistance. In addition, the AT4055 element
is protected by a hardened-steel windscreen. For e ven greater dura­bility 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

/8"-27 threads.

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 posi­tive voltage at Pin 2 in accordance with industry convention.

The AT4055 will operate in conjunction with any remote “phan­tom” or “simple x” po wer source supplying 48 v olts 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 e xternal 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.

40 SERIES PRECISION MICROPHONES

AT4055

500

1k

Frequency in Hertz

†

2

18 dB SPL

1.95" (49.5 mm) maximum head diameter

stands; 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/cm2 = 10 microbars = 94 dB SPL

1

Measured at diaphragm

2

Using Audio Precision System One

Dimensions

1.95"

10 dB

Response in dB

2k

10k

5k

20k

49.5 mm

Specifications

ELEMENT Externally polarized (DC bias) capacitor
POLAR PATTERN Cardioid (Unidirectional)
FREQUENCY RESPONSE 20-20,000 Hz
OPEN CIRCUIT SENSITIVITY (1 kHz) – 4 6 dB (5.0 mV) ± 2 dB, re 1V at 1 Pa*
IMPEDANCE 200 ohms
MAXIMUM INPUT SOUND LEVEL 147 dB SPL, 1 kHz at 1% T.H.D.
NOISE, TYPICAL (A-WEIGHTED)
DYNAMIC RANGE, TYPICAL 129 dB, 1 kHz at Max SPL
SIGNAL-TO-NOISE RATIO, TYPICAL 76 dB, 1 kHz at 1 Pa*
POWER REQUIREMENTS 48V DC phantom (±4V)
CURRENT CONSUMPTION, TYPICAL 4.0 mA
WEIGHT (LESS CABLE AND CLAMP) 10.6 oz (300 grams)
DIMENSIONS 6.97" (17 7.0 mm) long,

ACCESSORIES FURNISHED AT8406 tapered clamp for 5/8"-27 threaded

Frequency Response

50

100 200

LEGEND

12" or more on axis

Optional Accessories:

• AT8114 foam windscreen (slip-on).

• AT8314 2-conductor, shielded,
vinyl-jacketed, broadcast-type cable
with XLRF-type connector at microphone

1

end, XLRM-type connector at equipment
end. Available in 10', 20', 25', 30', 50'
& 100' lengths.

• AT8407 universal “clothes-pin” stand
clamp fits both tapered and cylindrical
microphones.

• AT8410a shock mount for boom or stand
operation. Universal “clothes-pin” clamp
fits tapered and cylindrical microphones.

• AT8415 shock mount for boom or stand
operation.

• CP8506 four-channel 48V phantom
power supply (AC powered).

• AT8801 single-channel 48V phantom
power supply (AC powered).

Audio-Technica microphones and accessories purchased
in the U.S.A. are warranted for one year from date of
purchase by Audio-Technica U.S., Inc. (A.T.U.S.) to be
free of defects in materials and workmanship. In event of
such defect, product will be repaired promptly without
charge or, at our option, replaced with a new product of
equal or superior value if delivered to A.T.U.S. or an
Authorized Service Center, prepaid, together with the
sales slip or other proof of purchase date.

from A.T.U.S. is required for return.

excludes defects due to normal wear, abuse, shipping
damage, or failure to use product in accordance with
instructions. This warranty is void in the event of un­authorized repair or modification, or removal or defacing
of the product labeling.

For return approval and shipping information,

the Service Department, Audio-Technica U.S., Inc., 1221
Commerce Drive, Stow, Ohio 44224.

Except to the extent precluded by applicable state law,

A.T.U.S. will have no liability for any consequential,
incidental, or special damages; any warranty of
merchantability or fitness for particular purpose
expires when this warranty expires.

This warranty gives you specific legal rights, and you may
have other rights which vary from state to state.

Outside the U.S.A., please contact your local dealer for
warranty details.

One-Year Limited Warranty

Prior approval

This warranty

contact

Polar Pattern

0

330

300

270

240

210

180

LEGEND

200 Hz Same as 1 kHz

1 kHz
5 kHz
8 kHz

SCALE IS 5 DECIBELS PER DIVISION

Audio-Technica U.S., Inc., 1221 Commerce Drive, Stow, Ohio 44224
Audio-Technica Limited, Old Lane, Leeds LS11 8AG England

Form No. 0345- 0821-0 0-B / W 1997 Audio-Technica U.S., Inc. Printed in U.S.A.

30

60

90

120

150

6.97"

177.0 mm

1.26" to 0.87"

32.0 mm to 22.0 mm