Audio Technica UniPoint AT857QMa 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 small-
diameter 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
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
of the
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.
Frequency Response
50 100 200 500
Frequency in Hertz
12" or more on axis (flat)
LEGEND
Roll-off
AT857QMa
AT857QMLa
CARDIOID
CONDENSER
QUICK-MOUNT
GOOSENECK
MICROPHONES
10 dB
1k 2k 5k 10k 20k