• Specially engineered to meet the most critical acoustic
requirements of professional recording, broadcast and sound
reinforcement
• Direct-coupled, balanced output results in a clean signal even
under high-output conditions
• Transformerless circuitry virtually eliminates low-frequency
distortion and provides superior correlation of high-speed
transients
• Rugged turned-brass microphone housing for enduring
dependability
• State-of-the-art design and manufacturing techniques ensure
compliance with A-T’s stringent consistency and reliability
standards
The AT4051a is intended for use in professional applications where
remote power is available. It requires 48V DC phantom power,
which may be provided by a mixer or console, or by a
separate, in-line source such as the Audio-Technica AT8801 single-
channel and CP8506 four-channel phantom power supplies.
Output from the microphone’s XLRM-type connector 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 integral 80 Hz high-pass filter provides easy switching from a flat
frequency response to a low-end roll-off. The high-pass 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.
The AT4051a consists of two modular subassemblies: an
AT4900a-48 body and an AT4051a-EL head capsule (both available
separately). Additional interchangeable capsules are available in
omnidirectional (AT4049a-EL) and hypercardioid (AT4053a-EL).
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.
One-Year Limited Warranty
Audio-Technica brand products 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. Prior approval from A.T.U.S. is required for return. This warranty 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, contact 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.
AT4051a SPECIFICATIONS
†
ELEMENT
Externally polarized (DC bias)
condenser
POLAR PATTERN
Cardioid
FREQUENCY RESPONSE
20-20,000 Hz
LOW FREQUENCY ROLL-OFF
80 Hz, 12 dB/octave
OPEN CIRCUIT SENSITIVITY
–34 dB (19.9 mV) re 1V at 1 Pa*
IMPEDANCE
100 ohms
MAXIMUM INPUT SOUND LEVEL
146 dB SPL, 1 kHz at 1% T.H.D.
NOISE
1
19 dB SPL
DYNAMIC RANGE (typical)
127 dB, 1 kHz at Max SPL
SIGNAL-TO-NOISE RATIO
1
75 dB, 1 kHz at 1 Pa*
PHANTOM POWER
48V DC, 3.2 mA typical
REQUIREMENTS
SWITCH
Flat, roll-off
WEIGHT (less accessories)
4.2 oz (120 g)
DIMENSIONS
6.10" (155.0 mm) long, 0.83"
(21.0 mm) body diameter
OUTPUT CONNECTOR
Integral 3-pin XLRM-type
ACCESSORIES FURNISHED
AT8405 stand clamp for
5
/
8
"-27
threaded stands; AT8159
windscreen; 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 /cm
2
= 10 microbars = 94 dB SPL
1
Typical, A-weighted, using Audio Precision System One.
Specifications are subject to change without notice.
Audio-Technica U.S., Inc.,
1221 Commerce Drive, Stow, Ohio 44224
Audio-Technica Limited,
Old Lane, Leeds LS11 8AG England
www.audio-technica.com
P51458-EN ©2002 Audio-Technica U.S., Inc. Printed in U.S.A.
AT4051a
CARDIOID CONDENSER MICROPHONE
12" or more on axis
100
50
200
LEGEND
Roll-off
10k
5k
1k
500
2k
20k
Frequency in Hertz
Frequency Response
Response in dB
10 dB
8 kHz
Polar Pattern
180
SCALE IS 5 DECIBELS PER DIVISION
LEGEND
200 Hz
1 kHz
5 kHz
270
240
210
300
330
0
150
120
90
30
60
