Audio Technica Propoint PRO 44 Specifications

PRO 44
CARDIOID UNIDIRECTIONAL
BOUNDARY MICROPHONE
Description
The PRO 44 is a wide-range condenser
microphone with a hemi-cardioid (half-space
cardioid) polar pattern. It was designed for
surface-mounted applications in high-quality
sound reinforcement and other demanding
sound pickup situations. Its low-profile design
makes the PRO 44 ideal for use in applica-
tions where minimum visibility is required.
The PRO 44 can be powered from any external
9V to 52V DC phantom power source. A
25' (7.6 m) cable with TA3F and XLRM-type
connectors is provided for use between the
microphone and electronics input.
Audio-Technica design engineers have utilized
the newest low-mass technology in the quest
for superior performance. The charge is now on
the fixed back plate, rather than the moving
element. With the A-T fixed-charge "back plate"
construction, a gold-vaporized diaphragm just
2 microns thick (about 0.000079") can be used.
This reduces moving mass substantially,
improving frequency response and transient
response while reducing distortion.
Positioning a properly designed miniature
unidirectional microphone centrally on a large,
flat, unobstructed surface yields several dis-
tinct advantages. Directionality is increased
by 3 dB, promoting enhanced gain before
feedback and further suppression of ambient
noise. Sensitivity is increased for improved
signal-to-noise ratio. Phase distortion due to
reflected sound energy from the boundary
itself is eliminated.
The microphone element is enclosed in a
rugged housing with a black finish. The rubber
non-slip bottom pad minimizes mechanical
coupling of surface vibrations to the micro-
phone.
Operation and Maintenance
The symmetry and area of the mounting
surface directly affect the sensitivity of the
boundary microphone at low frequencies.
Ideally, the mounting surface should be circu-
lar; however, square or rectangular surfaces
are most often used. If the mounting surface
is rectangular, the smaller dimension tends to
determine low-frequency cutoff. The micro-
phone should be centered on the surface and
positioned with the front of the microphone
facing the sound source along the longer
dimension of the mounting surface. The
sound source should not be below, or higher
than 60° above, the plane of the mounting
surface.
60
IDEAL
WORKING
ANGLE
Output is low impedance balanced. The bal-
anced 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.
DC phantom power (9-52 volts) must be
applied equally to Pins 2 and 3, with the
ground for the power supply connected to
Pin 1. This can be provided by a console or
mixer with built-in phantom voltage or with the
addition of an in-line phantom power supply,
such as the recommended Audio-Technica
CP8506 and AT8801 power supplies.
The high sensitivity of the PRO 44 ensures
useful output and an excellent match to most
mixer, tape recorder and amplifier inputs. It
will provide undistorted output even in sound
fields as loud as 114 dB SPL. However, due
to the high sensitivity, in some instances it
may be possible to overload sensitive input
stages. If distortion occurs, first check for
input overload. In such cases, an attenuator
such as the Audio-Technica AT8202 may be
required between the mic and the electronics
input. (Also, many mixers provide "input pad"
switches to reduce mic-input signal levels.)
While a modern condenser microphone is not
unduly sensitive to the environment, tempera-
ture 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.
Frequency Response
500
50 100 200 1k 2k
Frequency in Hertz
LEGEND 12" or more on axis
10 dB
5k 10k 20k