OMNIDIRECTIONAL
CAPACITOR MICROPHONE
AT4049a
Description
The
AT
4049a is a transformerless externally-polarized capacitor
studio microphone. It has been specially engineered to meet the
most critical acoustic requirements of professional recording and
broadcast.
The
AT
4049a features a smooth, flat frequency response over
its extended 20-20,000 Hz range. The omnidirectional head capsule
may be easily removed, stored and replaced with an optional
cardioid or hypercardioid capsule to meet the needs of the widest
range of miking applications.
The balanced output is direct-coupled, resulting in a clean
signal even under high-output conditions. The microphone is totally
free of the distortion associated with conventional transformer-coupled
outputs. Its fast response to transients contributes to the open,
transparent reproduction of even the most troublesome of instru-
ments and sound effects.
The
AT
4049a combines the benefits of exceptionally low self-
noise with very high output. Equally important,
it
handles very high
sound pressure levels with ease—up to 146 dB SPL while producing
no greater than 1% T.H.D. The
AT
4049a may be used with confidence
in a wide variety of miking applications, even under the stringent
demands of modern digital recording systems.
An integral 80 Hz hi-pass filter provides easy switching from a
flat frequency response to a low-end roll-off. The hi-pass switch is
recessed to prevent accidental activation. The hi-pass position
reduces the microphone’s sensitivity to “popping” in close vocal use
and to handling noise. It also attenuates unwanted low-frequency
ambient noise (from traffic, air-handling systems, etc.) and room
reverberation. Use of the supplied foam windscreen helps reduce
wind and “popping” noise.
A rugged microphone, the
AT
4049a housing is constructed of
turned brass, rather than thin-wall aluminum. Its surface is plated in
black chrome for durability and low reflectivity.
The
AT
4049a will operate in conjunction with any remote “phantom”
or “simplex” power source supplying 48 volts DC. The phantom
voltage not only powers the microphone’s impedance converter, but
is stepped-up to a higher voltage internally to polarize the capacitor
element.
Modular Expansion Capability
The
AT
4049a consists of two modular subassemblies which
are threaded together: the
AT
4900a-48 handle containing the micro-
phone’s electronics, and the
AT
4049a-EL capacitor head capsule.
The versatility of the
AT
4049a may be increased through
the addition of optional accessory head capsules. The
AT
4051a-EL
capsule provides the advantages of a smooth, wide-response
cardioid pattern. The
AT
4053a-EL hypercardioid element offers
excellent side rejection for increased working distance, and a highly
uniform polar pattern that virtually eliminates off-axis coloration.
A compartmentalized protective carrying case accommodates
the microphone, stand adapter, windscreen and two optional head
capsules.
Architects and Engineers Specifications
The microphone shall have a frequency response of
20 Hz to 20,000 Hz. Its capacitor element shall be of a DC bias
design and shall obtain its polarizing voltage and impedance-
converter power from an external 48V DC (±4V) phantom power
source. The microphone shall have an omnidirectional polar pattern.
The element shall be interchangeable with optional capsules offer-
ing cardioid or hypercardioid polar patterns.
Nominal open-circuit output voltage shall be 22.4 mV at 1 kHz,
1 Pascal. The microphone shall have an output impedance of 100
ohms and output shall be transformerless balanced. The micro-
phone shall accept a 146 dB SPL at 1 kHz while producing no
greater than 1% T.H.D.
The microphone shall have a length of 6.10" (155.0 mm), a
diameter of 0.83" (21.0 mm), and a weight of 4.2 oz (120 g). The
microphone housing shall be turned brass with a low-reflectance
black chrome finish.
The Audio-Technica
AT
4049a is specified.
40 SERIES PRECISION MICROPHONES
