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Frequency in Hertz
Response in dB
10 dB
20k
10k
5k
2k
1k
500
200100
50
Frequency Response
LEGEND
12" or more on axis
AT813a CARDIOID CONDENSER MICROPHONE
200 Hz
1 kHz
5 kHz
8 kHz
LEGEND
Same as 1 kHz
Polar Pattern
SCALE IS 5 DECIBELS PER DIVISION
90
60
120
30
150
210
240
270
300
330
180
0
• Ideal for close-up vocals, overheads, piano, and strings
• Cardioid polar pattern reduces pickup of sounds from the sides
and rear, improving isolation of desired sound source
• Proximity effect provides added warmth when used close up
• Large protective screen reduces “popping” and sibilant distortion
• Operates on battery or phantom power
The AT813a requires 9V to 52V DC phantom power
or a 1.5V AA
battery for operation. A battery need not be in place for phantom
power operation.
Battery installation: Unscrew the lower section of the microphone
body, just below the nameplate. Insert a fresh 1.5V AA battery
in the handle compartment (“+” end up), then reassemble the
microphone. Alkaline batteries are recommended for longest life.
Remove the battery during long-term storage.
AT813a SPECIFICATIONS
†
ELEMENT Fixed-charge back plate
permanently polarized
condenser
POLAR PATTERN Cardioid
FREQUENCY RESPONSE 30-20,000 Hz
OPEN CIRCUIT SENSITIVITY –44 dB (6.3 mV) /
(Phantom / Battery) –45 dB (5.6 mV) re 1V at 1 Pa*
IMPEDANCE (Phantom / Battery) 200 ohms / 270 ohms
MAXIMUM INPUT SOUND LEVEL 137 dB / 123 dB SPL,
(Phantom / Battery) 1 kHz at 1% T.H.D.
SIGNAL-TO-NOISE RATIO
1
70 dB, 1 kHz at 1 Pa*
DYNAMIC RANGE (typical) 113 dB / 99 dB,
(Phantom / Battery) 1 kHz at Max SPL
PHANTOM POWER 9-52V DC, 2 mA typical
UIREMENTS
REQ
BATTERY TYPE 1.5V AA/UM3
BATTERY CURRENT / LIFE 0.4 mA / 1200 hours typical
WEIGHT (less accessor
ies) 7.1 oz (200 g)
DIMENSIONS 7.60" (193.0 mm) long,
1.98" (50.3 mm) maximum
diameter
OUTPUT CONNECTOR Integral 3-pin XLRM-type
ACCESSORIES FURNISHED AT8405a stand clamp for 5/8"-27
threaded stands; battery; soft
protective pouch
†
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
1
Typical, A-weighted, using Audio Precision System One.
Specifications are subject to change without notice.
2
= 10 microbars = 94 dB SPL
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:
The high sensitivity of the A
Pin 1-to-Pin 1, etc.
T813a assures useful output and an
excellent match to most input sources. In some cases, however, an
attenuator such as the Audio-Technica AT8202 may be required
between the microphone and preamplifier to avoid overloading
sensitive input stages.
oid leaving the microphone in the open sun or in areas where
v
A
temperatures exceed 110° F (43° C) for extended periods.
Extremely high humidity should also be avoided.
Audio-Technica U.S., Inc., 1221 Commerce Drive, Stow, Ohio 44224
echnica Limited,
Audi
T
-
o
Old Lane, Leeds L
1 8AG England
1
S
www.audio-technica.com
P51653-EN ©2004 Audio-Technica U.S., Inc. Printed in Japan