Audio Technica UniPoint AT857QMa, UniPoint AT857QMLa Product Information

Description

The AT857QMa is a wide-range condenser
microphone designed for quality sound
reinforcement, professional recording,
television, and other demanding sound
pickup applications. A 3-pin male connector
insert at the base allows the AT857QMa to
be plugged directly into a 3-pin panel jack
connector or a standard microphone cable.
With an overall height of 14.51", its small­diameter alternating gooseneck design
permits highly flexible positioning while
maintaining a smooth, well-contoured
appearance. The AT857QMLa is a 19.00"
version of this microphone.

Supplied as a cardioid, the AT857QMa easily
accepts interchangeable elements to permit
selection of angle of acceptance from 100° to
360°. The following optional elements are
available from an authorized Audio-Technica
dealer or the A-T service department:
AT853H-ELE hypercardioid, AT853O-ELE
omnidirectional, AT853SC-ELE subcardioid.

Audio-Technica design engineers have
utilized the newest low-mass technology in
the quest for superior performance. The
permanent charge is now on the fixed back
plate, rather than the moving element. With
A-T fixed charge “back plate” construction, a
gold-vaporized diaphragm just 2 microns
thick (or about 0.000079") can be used. This
reduces moving mass, thus improving
frequency response and transient response
while reducing distortion. The result is
remarkable stability of performance.

A flat-response/ low-roll-off switch is built into
the integral power module of the
microphone. The low-roll-off feature
attenuates low-frequency response to
compensate for proximity effect if the unit is
used very close. Low roll-off can also be
used to minimize background ambiance, air
conditioning rumble, mechanical noise, etc.,
improving the quality of sound pickup under
difficult conditions.

The microphone element is enclosed in
a rugged housing with a low-reflectance
black finish.

Installation and Operation

The AT857QMa is a completely self-contained
unit ready to plug into a mating XLRF-type
panel jack or cable connector. An external
9V to 52V DC source is required to power
the unit.

Output is low impedance balanced. The
XLRM-type connector mates with XLRF-type
cable connectors. The balanced signal
appears across Pins 2 and 3, while the ground
(shield) connection is Pin 1. Output is phased
so that positive acoustic pressure produces
positive voltage at Pin 2, in accordance with
industry convention.

The provided AT8102 two-stage foam
windscreen simply slips over the head of the
microphone, effectively reducing wind noise
or “popping” when used extra close.

The small-diameter gooseneck is easy to
manipulate for proper positioning. Heavily
lubricated, it operates smoothly and quietly.
Should the unit become noisy with prolonged
use, apply a light machine oil directly on the
gooseneck area affected.

While a modern condenser microphone is
not unduly sensitive to the environment,
temperature extremes can be harmful.
Exposure to high temperatures can result
in gradual and permanent reduction of
the output level. Avoid leaving the
microphone in the open sun or in areas
where temperatures exceed 110° F (43° C)
for long periods of time. Extremely high
humidity should also be avoided.

Architects and Engineers Specifications

The microphone shall be a fixed-charge
condenser with a cardioid polar pattern and a
frequency response of 30 Hz to 20,000 Hz. It
shall be capable of accepting optional
interchangeable elements for additional polar
patterns. It shall operate from an external 9V
to 52V DC phantom power source. Nominal
open-circuit output voltage shall be 7.0 mV at
1 kHz, 1 Pascal. Output shall be low
impedance balanced (200 ohms).

The microphone shall have a self-contained
power module with an XLRM-type connector
insert at the base for direct connection to a
mating XLRF-type panel jack or cable
connector. The power module shall contain a
switch for low-frequency roll-off.

The microphone shall be a small-diameter
alternating gooseneck design with a length of

14.51" (368.6 mm) [19.00" (482.6 mm)]. Head
diameter shall be 0.47" (12.0 mm). The
microphone weight shall be 4.2 oz (120
grams) [4.4 oz (126 grams)]. Finish shall be
low-reflectance black.

The Audio-Technica AT857QMa [AT857QMLa]
is specified.

AT857QMa
AT857QMLa

CARDIOID
CONDENSER
QUICK-MOUNT
GOOSENECK
MICROPHONES

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

AT857QMa
AT857QMLa

Polar Pattern

AT857QMa/AT857QMLa SPECIFICATIONS

†

ELEMENT Fixed-charge back plate

permanently polarized condenser

POLAR PATTERN Cardioid (Unidirectional)
FREQUENCY RESPONSE 30-20,000 Hz
LOW-FREQUENCY ROLL-OFF 150 Hz, 6 dB/octave
OPEN CIRCUIT SENSITIVITY –43 dB (7.0 mV) re 1V at 1 Pa*
IMPEDANCE 200 ohms
MAXIMUM INPUT SOUND LEVEL 139 dB SPL, 1 kHz at 1% T.H.D.
DYNAMIC RANGE (TYPICAL) 112 dB, 1 kHz at Max SPL
SIGNAL-TO-NOISE RATIO

1

67 dB, 1 kHz at 1 Pa*

SWITCH Flat response, low-roll-off (recessed)
PHANTOM POWER REQUIREMENTS 9-52V DC, 2 mA typical
WEIGHT (AT857QMa) 4.2 oz (120 grams)

(AT857QMLa) 4.4 oz (126 grams)

DIMENSIONS (AT857QMa) 14.51" (368.6 mm) long

(AT857QMLa) 19.00" (482.6 mm) long
(BOTH) 0.47" (12.0 mm) head diameter

0.98" (25.0 mm) power module diameter

OUTPUT CONNECTOR (POWER MODULE) Integral 3-pin XLRM-type
ACCESSORY FURNISHED AT8102 two-stage foam windscreen
OPTIONAL INTERCHANGEABLE ELEMENTS AT853H-ELE hypercardioid (100°)

AT853O-ELE omnidirectional (360°)
AT853SC-ELE subcardioid (170°)

†

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.

Optional Accessories:

• AT8104a large metal windscreen.

• AT8117 large foam windscreen.

• AT8314 2-conductor, shielded, vinyl-jacketed,
broadcast-type cable with XLRF-type
connector at microphone end, XLRM-type
connector at equipment end. Available in
10', 20', 25', 30', 50' & 100' lengths.

• AT8416 shock mount.

• CP8201 line matching transformer
(Lo-Z to 50,000 ohms).

• CP8506 four-channel 48V phantom power
supply (AC powered).

• AT8801 single-channel 48V phantom power
supply (AC powered).

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 unauthorized repair
or modification.

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.

Audio-Technica U.S., Inc., 1221 Commerce Drive, Stow, Ohio 44224
Audio-Technica Limited, Old Lane, Leeds LS11 8AG England

Form No. 0310-0821-05-B/ W P50877-01 © 1998 Audio-Technica U.S., Inc. Printed in U.S.A.

0.98"

25.0 mm

1.39"

35.2 mm

92.4 mm

3.64"

368.6 mm

14.51"

0.47"

12.0 mm

12.0 mm

0.47"

482.6 mm

19.00"

0.98"

25.0 mm

1.39"

35.2 mm

92.4 mm

3.64"

AT857QMa

Dimensions

AT857QMLa
Dimensions

200 Hz

1 kHz
5 kHz
8 kHz

LEGEND

SCALE IS 5 DECIBELS PER DIVISION

90

60

120

30

150

210

240

270

300

330

180

0