200 Hz
1 kHz
5 kHz
8 kHz
LEGEND
Same as 5 kHz
Polar Pattern
SCALE IS 5 DECIBELS PER DIVISION
90
60
120
30
150
210
240
270
300
330
180
0
LEGEND
Roll-off
12" or more on axis (flat)
Frequency in Hertz
Response in dB
10 dB
20k
10k
5k
2k
1k
500
200
100
50
Frequency Response
• Designed for video production and broadcast (ENG/EFP) audio
acquisition
•Provides the narrow acceptance angle desirable for long-distance
sound pickup
• Excellent sound rejection from the sides and rear of mic
• Switchable low-frequency roll-off
• Operates on battery or phantom power
The AT815b 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.
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.
An integral 180 Hz high-pass filter provides easy switching from a flat
frequency response to a low-end roll-off.The roll-off position
reduces the pickup of low-frequency ambient noise (such
as traffic, air-handling systems, etc.), room reverberation and
mechanically coupled vibrations.
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.
AT815b SPECIFICATIONS†
ELEMENT Fixed-charge back plate
permanently polarized
condenser
POLAR PATTERN Line + gradient
FREQUENCY RESPONSE 30-20,000 Hz
LOW-FREQUENCY ROLL-OFF 180 Hz, 12 dB/octave
OPEN CIRCUIT SENSITIVITY –38 dB (12.5 mV) /
(Phantom / Battery) –39 dB (11.2 mV) re 1V at 1 Pa*
IMPEDANCE (Phantom / Battery) 500 ohms / 600 ohms
MAXIMUM INPUT SOUND LEVEL 130 dB / 115 dB SPL,
(Phantom / Battery) 1 kHz at 1% T.H.D.
SIGNAL-TO-NOISE RATIO170 dB, 1 kHz at 1 Pa*
DYNAMIC RANGE (typical) 106 dB / 91 dB,
(Phantom / Battery) 1 kHz at Max SPL
PHANTOM POWER 9-52V DC, 2 mA typical
REQUIREMENTS
BATTERY TYPE 1.5V AA/UM3
BATTERY CURRENT / LIFE 0.4 mA / 1200 hours typical
SWITCH Flat, roll-off (recessed)
WEIGHT (less accessories) 7.1 oz (200 g)
DIMENSIONS 18.11" (460.0 mm) long,
0.83" (21.0 mm) diameter
OUTPUT CONNECTOR Integral 3-pin XLRM-type
ACCESSORIES FURNISHED AT8405a stand clamp for 5/8"-27
threaded stands; windscreen;
battery; 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
1Typical, 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
P51654-EN ©2004 Audio-Technica U.S., Inc. Printed in Japan
AT815b LINE + GRADIENT CONDENSER MICROPHONE
