Audio Technica ONEPOINT AT825 User manual

SPECIAL PURPOSE MICROPHONES
Description
The AT825, an X/Y stereo condenser micro-
phone with full mono compatibility, has been
designed for broadcast and professional
recording use. It is also well-suited for DAT
field applications. Equally appropriate for
hand-held or camera-mount use, the AT825
microphone provides full, natural stereo ambi-
ence in a compact, lightweight design.
Operators working on hectic ENG assignments
will discover the AT825’s ability to readily
respond to the typical configuration for broad-
cast audio. This includes true stereo ambience
(crowd noise, music, etc.) mixed with narrative
talent on a center mono channel. Under a
deadline crunch or in single-take situations,
sound technicians will also appreciate the
AT825’s excellent channel separation.
The AT825 is equipped with a pair of wide-
range, closely-matched, optimally-positioned
miniature condenser cardioid elements.
Because the polar response vs. frequency of
these elements is so uniform, the AT825 pro-
vides the spatial impact and realism of a live
sound field, while simultaneously remaining
full and uniform when operating in mono
(L+R). Consistently natural-sounding response
is maintained over an arc of approximately 220°,
and the L+R mono polar pattern is virtually
free of lobes and comb effects.
The AT825 takes full advantage of
Audio-Technica’s condenser technology, pro-
viding an ultra-low-mass diaphragm for superb
transient response. Engineered with a perma-
nently-charged fixed back plate, the element
features a diaphragm reduced to a mere
2-micron thickness (about 0.000079"). The
results are minimal distortion, and improved
frequency and transient response. Frequency
response is smooth and peak-free over an
extended 30 Hz to 20,000 Hz range.
True to its field-ready billing, the AT825 features
a switchable low-roll-off filter, windscreen,
and two-way power. An external 5-52V DC
phantom power supply, or an internal 1.5V
AA/UM3 battery (included), may be used. On
battery, current demands are so low that battery
life exceeds 1,000 hours in normal intermittent
use. The battery is automatically bypassed when
phantom power is present. The supplied 16.5'
shielded cable features a five-pin XLRF-type
input connector and two standard three-pin
XLRM-type output connectors. A snap-in
microphone stand adapter is included for
mounting to any stand with 5/8"-27 threads. A
compact, soft vinyl pouch is provided to hold
and protect the microphone and accessories.
Operation and Maintenance
Before attempting operation, if battery opera-
tion is desired, install the battery. Unscrew
the upper section of the handle of the micro-
phone and slide it down to reveal the battery
compartment. Place battery in handle
compartment, then reassemble the microphone.
Be certain to observe battery polarity as
indicated (+ end forward). Replacement AA
batteries are readily available. While standard
carbon-zinc batteries will operate the micro-
phone satisfactorily, alkaline or mercury
batteries are preferred for longer service life.
Only “leakproof” batteries should be used.
The two stereo outputs are low impedance
balanced. The balanced signals appear across
Pins 2 and 3 for the left channel and Pins 4
and 5 for the right channel. The ground
(shield) connection for both channels is Pin 1.
Output is phased so that positive acoustic
pressure produces positive voltage at Pins 2
and 4, in accordance with industry convention.
By locating the AT825 near the sound source,
the stereo image width will be enhanced, but
the room ambience will be decreased.
Conversely, as the mic position recedes from
the sound source, a narrower left/right stereo
image will be achieved and more of the
“room sound” will be noted. After experimenting
with placement, operators will soon get the
“feel” of where to position the AT825 for the
best overall effect.
The high sensitivity of the AT825 assures useful
output under most circumstances, and it is
designed to provide a distortion-free signal
even in very intense sound fields. In some
cases, however, an attenuator such as the
Audio-Technica AT8202 may be required
between each microphone output and its
preamplifier to avoid overloading sensitive
input stages.
Architects and Engineers Specifications
The microphone shall be a fixed-charge
condenser with two condenser cardioid
elements in an X/Y stereo configuration. The
stereo angle shall be 110°. The frequency
response shall be 30 Hz to 20,000 Hz, and the
microphone shall have a switch for selection
of flat or low-roll-off response.
The microphone shall have a nominal
open-circuit output voltage of 4.4 mV at 1 kHz,
1 Pascal. It shall have an output impedance of
200 ohms and output shall be balanced. It
shall be capable of operating from an external
5V to 52V DC phantom power source or,
alternatively, from a 1.5V AA/UM3 battery.
The microphone shall accept a 126 dB SPL
at 1 kHz while producing no greater than
1% T.H.D.
The microphone shall include a foam wind-
screen and 16.5' shielded cable with a five-pin
XLRF-type stereo connector and two standard
three-pin XLRM-type output connectors. The
microphone shall be 8.43" (214.0 mm) long
and the head shall be 2.44" (62.0 mm) wide.
The weight shall be 8.5 oz (240 grams). Finish
shall be low-reflectance matte.
The Audio-Technica AT825 is specified.
Frequency Response
LEGEND Roll-off
12" or more on axis (flat)
Frequency in Hertz
Response in dB
10 dB
20k
10k
5k
2k
1k
500
200100
50
AT825
ONEPOINT®
X/Y STEREO
FIELD RECORDING
MICROPHONE

AT825 SPECIFICATIONS†
ELEMENTS Fixed-charge back plate
permanently polarized condenser
POLAR PATTERN X/Y stereo
FREQUENCY RESPONSE 30-20,000 Hz
LOW-FREQUENCY ROLL-OFF 150 Hz, 6 dB/octave
OPEN CIRCUIT SENSITIVITY –47 dB (4.4 mV) re 1V at 1 Pa*
CHANNEL BALANCE ≤2.5 dB
IMPEDANCE 200 ohms balanced
MAXIMUM INPUT SOUND LEVEL 126 dB SPL, 1 kHz at 1% T.H.D.
SIGNAL-TO-NOISE RATIO170 dB, 1 kHz at 1 Pa*
DYNAMIC RANGE (TYPICAL) 102 dB, 1 kHz at Max SPL
PHANTOM POWER REQUIREMENTS 5-52V DC, 2 mA typical (each channel)
BATTERY TYPE Use only “leakproof” AA/UM3 1.5V battery
BATTERY CURRENT 2 mA typical
BATTERY LIFE (INTERMITTENT USE) More than 1000 hours (alkaline battery)
SWITCH Flat, roll-off (recessed)
WEIGHT (LESS CABLE AND ACCESSORIES) 8.5 oz (240 grams)
DIMENSIONS 8.43" (214.0 mm) long, 2.44" (62.0 mm) head width,
0.83" (21.0 mm) body diameter
OUTPUT CONNECTOR Integral 5-pin XLRM-type
CABLE 16.5' (5 m) long, 8 conductors under two shields,
vinyl-jacketed, stereo cable with 5-pin XLRF-type
connector at microphone end, two 3-pin
XLRM-type connectors at output end
ACCESSORIES FURNISHED AT8405 snap-in stand clamp for 5/8"-27
threaded stands; battery; AT8120 windscreen;
soft vinyl 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/cm2= 10 microbars = 94 dB SPL
1Typical, A-weighted, using Audio Precision System One.
Optional Accessories:
• AT8202 adjustable in-line attenuator for use
with balanced Lo-Z microphones.
• AT8407 universal “clothes-pin” stand clamp
fits both tapered and cylindrical microphones.
• AT8415 low-profile 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).
Stereo
Polar Pattern
Dimensions
XLRM-type Plug Wiring
Low Impedance Balanced
Five-pin XLRF-type Plug Wiring
5
4
3
21
LEFT
1 kHz
LEGEND
1 kHz
RIGHT
SCALE IS 5 DECIBELS PER DIVISION
90
60
120
30
150
210
240
270
300
330
180
0
Mono (L +R)
Polar Pattern
1 kHz
LEGEND
SCALE IS 5 DECIBELS PER DIVISION
90
60
120
30
150
210
240
270
300
330
180
0
AT825
One-Year Limited Warranty
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.
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 unau-
thorized repair or modification.
For return approval and shipping information, con-
tact 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 mer-
chantability 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.
Form No. 0308-9501-04-B/W © 1998 Audio-Technica U.S., Inc. Printed in U.S.A.
Audio-Technica U.S., Inc., 1221 Commerce Drive, Stow, Ohio 44224
Audio-Technica Limited, Old Lane, Leeds LS11 8AG England
0.83"
21.0 mm
62.0 mm
2.44"
214.0 mm
8.43"
PIN 1 – SHIELD LEFT & RIGHT
PIN 2 – YEL / YEL LEFT
PIN 3 – RED/RED LEFT
PIN 4 – YEL /YEL RIGHT
PIN 5 – RED/RED RIGHT