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AT4021
Cardioid Condenser End-Address Microphone
Features
• Specially engineered to meet the most critical acoustic
requirements of professional recording, broadcast and sound
reinforcement
• Low self-noise perfectly suited for the most sophisticated
recording equipment
• Low-mass diaphragm improves transient response, increases
response bandwidth and reduces handling and mechanical
noise transfer
• Cardioid polar pattern reduces pickup of sounds from the sides
and rear, improving isolation of desired sound source
• Rugged design and construction for reliable performance
• Integral 80 Hz high-pass lter switch and 10 dB pad switch
• State-of-the-art design and manufacturing techniques ensure
compliance with A-T’s stringent consistency and reliability
standards
Description
The AT4021 is a xed-charge condenser microphone with a cardioid polar
pattern. It is designed to meet the demands of critical studio and live
applications.
40 series studio microphones
An integral 80 Hz high-pass lter provides easy switching from a at
frequency response to a low-end roll-off. The roll-off position reduces
the pickup of low-frequency ambient noise (such as trafc, air-handling
systems, etc.), room reverberation and mechanically coupled vibrations.
To engage the high-pass lter, slide the switch toward the “bent” line.
The microphone is also equipped with a switchable 10 dB pad that lowers
the microphone’s sensitivity, thus providing higher SPL capability for
exible use with a wide range of users and system congurations. To
engage the 10 dB pad, slide the switch toward the -10 position.
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 Specications
The microphone shall be a xed-charge condenser. It shall have a cardioid
polar pattern with a uniform 120° angle of acceptance and a frequency
response of 20 Hz to 20,000 Hz. The microphone shall operate from an
external 48V DC phantom power source. It shall be capable of handling
sound input levels up to 146 dB (156 dB with 10 dB pad) with a dynamic
range of 132 dB. Nominal open-circuit output voltage shall be 19.9 mV at
1V, 1 Pascal. Output shall be low impedance balanced (250 ohms).
The output of the microphone shall be a 3-pin XLRM-type connector.
The microphone shall be equipped with a switchable 10 dB pad and a
switch that permits choice of at response or 80 Hz low-frequency roll-off.
The microphone shall be 144.0 mm (5.67") long and have a diameter of
21.0 mm (0.83"). Weight shall be 119 grams (4.2 oz). The microphone shall
include a stand clamp, a windscreen and a protective carrying case.
The Audio-Technica AT4021 is specied.
The microphone requires 48V phantom power for operation.
The cardioid polar pattern of the microphone is more sensitive to sound
originating directly in front of the element, making it useful for controlling
feedback and reducing pickup of unwanted sounds.
The output of the microphone is a 3-pin XLRM-type connector.
The microphone is equipped with a switchable 10 dB pad and a switch
that permits choice of at response or low-frequency roll-off (via integral
80 Hz high-pass lter).
The microphone is enclosed in a rugged housing. The included AT8405a
stand clamp permits mounting on any microphone stand with 5/8"-27
threads. A windscreen and a protective carrying case are also included.
Operation and Maintenance
The AT4021 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.
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Specications
Element
Polar pattern
Frequency response
Low frequency roll-off
Open circuit sensitivity
Impedance
Maximum input sound level
Noise
Dynamic range (typical)
Signal-to-noise ratio1
Phantom power requirements
Switch(es)
Weight
Dimensions
Output connector
Audio-Technica case style
Accessories furnished
In the inter est of standards devel opment, A.T.U.S.
offers full details on its test me thods to other industr y
1 Pascal = 1 0 dynes/cm
1
Typical, A-weighted, using Audio Precision System One.
Specication s are subject to chang e without notice.
professional s on request.
2
= 10 microb ars = 94 dB SPL
AT4021
Fixed-charge back plate, permanently
polarized condenser
Cardioid
20-20,000 Hz
80 Hz, 12 dB/octave
–34 dB (19.9 mV) re 1V at 1 Pa
250 ohms
146 dB SPL, 1 kHz at 1% T.H.D.;
156 dB SPL, with 10 dB pad (nominal)
1
14 dB SPL
132 dB, 1 kHz at Max SPL
80 dB, 1 kHz at 1 Pa
48V DC, 3.0 mA typical
Flat, roll-off; 10 dB pad (nominal)
119 g (4.2 oz)
144.0 mm (5.67") long,
21.0 mm (0.83") diameter
Integral 3-pin XLRM-type
S1
AT8405a stand clamp for 5/8"-27
threaded stands; AT8159 windscreen;
protective carrying case
229
frequency response: 20– 20,000 Hz
10 dB
100
12" or more on axis
Roll-off
330˚
200
Frequency in Hertz
0˚
180˚
500
30˚
150˚
5k
2k
1k
60˚
120˚
10k
90˚
LEGEND
200 Hz
1 kHz
5 kHz
8 kHz
50
LEGEND
polar pattern
300˚
270˚
240˚
210˚
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
©2010 Audio-Technica U.S., Inc. audio-technica.com 0001-0206-01
Response in dB
20k