Description
The AT3525 is a wide-range fixed-charge
condenser microphone with a cardioid polar
pattern. Featuring excellent performance
specifications, this versatile microphone is
designed to meet the needs of professional
musicians in a wide range of applications,
from project studio recording to high-quality
sound reinforcement. It is also suitable for
use in broadcasting and other situations
which demand exceptional audio reproduc-
tion coupled with enduring reliability.
Audio-Technica design engineers have
utilized the newest low-mass technology in
the quest for superior performance. The back
plate of the AT3525 element holds a fixed
charge and has been aged to provide energy
stabilization. The surface of the back plate has
been precision-milled to ensure maximum
charge linearity. The result is a reduction in
both frequency response peaks and
diaphragm break-up distortion.
The Audio-Technica fixed-charge condenser
element design allows significant diaphragm
weight reduction. The low-mass diaphragm
improves transient response, increases
response bandwidth and reduces handling
and mechanical noise transfer.
The symmetrical housing assembly surround-
ing the microphone capsule and its open
acoustical environment allow the off-axis
response to be ideally suited for studio work
where natural reproduction of off-axis sound
is of paramount importance.
The AT3525 is intended for use in professional
applications where remote power is available.
It requires 48V phantom power, which may be
provided by a mixer or console, or by a sepa-
rate, in-line source such as the Audio-Technica
AT8801 single-channel and CP8506 four-
channel phantom power supplies.
The cardioid (unidirectional) polar pattern of
the AT3525 is more sensitive to sound origi-
nating directly in front of the element than to
sounds coming from the sides or rear.
Unidirectional microphones are useful in
controlling feedback, reducing pickup of
unwanted sounds and providing isolation
between performers during recording. They
can also be used to allow greater microphone-
to-performer distance with equal noise,
compared to an omnidirectional microphone.
The AT3525 handles very high sound pres-
sure levels with ease, accepting as high as
146 dB SPL before producing 1% T.H.D. A
switchable 10 dB (nominal) pad is built-in,
increasing its capabilities to 156 dB SPL.
An integral 80 Hz hi-pass filter provides easy
switching from a flat frequency response to a
low-end roll-off. The hi-pass position reduces
the microphone’s sensitivity to popping in
close vocal use. It also reduces the pickup of
low-frequency ambient noise (such as traffic,
air-handling systems, etc.), room reverbera-
tion and mechanically-coupled vibrations.
The AT3525 is enclosed in a rugged housing
with a low-reflectance finish. Output is via a 3-
pin professional connector. The included multi-
position shock mount permits mounting on any
microphone stand or boom with 5/8"-27 threads.
The mounting arm may be removed from the
shock-mount ring and reattached for a “hang-
ing” orientation, as shown in the photo.
Operation and Maintenance
Output is low impedance balanced. The output
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.
For balanced low-impedance inputs, AT8314
cable (or equal) is recommended. An accom-
panying drawing shows the wiring used at
the equipment end of this cable. Note that
other manufacturers may employ other color
codes for cable conductors. Regardless of
color code, it is important that both ends of
each cable are wired consistently, with the
shield always connected to Pin 1, Pin 2
connected to Pin 2, and Pin 3 to Pin 3. This
will ensure that all microphones are electri-
cally in phase and reduce problems of
uneven response and sound cancellation
when two microphones are used close to
each other.
Secure the cable to the mic stand or boom,
leaving a slack loop at the mic. This will
ensure the most effective shock isolation and
reduce the possibility of accidentally pulling
the microphone unit out of its mount.
While a modern condenser microphone is not
unduly sensitive to the environment, temper-
ature 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.
AT3525
CARDIOID
CONDENSER
MICROPHONE
Frequency Response
