Shure SM90 Technical Data

THE SOUND OF THE PROFESSlONALS
GENERAL
The SM90 Microphone is designed specifically for
surface-mounted applications. It is a professional-
quality permanently-biased condenser microphone with
a hemispherical pickup pattern (omnidirectional in the
hemisphere above the mounting surface.)
The SM90 takes advantage of the well-known princi-
ple that, at a barrier or boundary, sound pressure
doubles compared to its value if the boundary is re-
moved. When placed sufficiently near the boundary sur-
face, a microphone has effectively 6 dB higher sensi-
tivity and approximately 3 dB greater rejection of ran-
dom background noise.
Because of its high sensitivity and extremely flat fre-
quency response, the SM90 can be used for distant
pickup in circumstances where close miking would not
be practical. The low-frequency cutoff switch in the pre-
amplifier permits using the SM90 even in environments
where low-frequency noise (e.g., from fans or air condi-
tioners) would otherwise make distant pickup impossi-
ble. And the omnidirectional polar pattern of the SM90
means sound is picked up equally in the full 360° hemi-
sphere around the microphone; there is no off-axis
sound coloration or variation.
The SM90 can also be used for close pickup of an in-
dividual instrument, mounted, for instance, inside the
lid of a grand piano or on the floor next to a bass drum.
Experimentation and critical listening will demonstrate
Copyright 1984, Shure Brothers Inc.
27A2162 (DJ)
222 HARTREY AVE., EVANSTON, IL. 60204 U.S.A.
AREA CODE 312/866-2200
P R O F E S S I O N A L P R O D U C T S
®
the best location for any particular purpose or effect
desired.
an entirely new cartridge, developed at Shure. The result
is high output and extremely faithful sound reproduc-
tion across the entire audio frequency range. The sup-
plied low-distortion, high-clipping-level preamplifier pro-
vides switch-selectable low-frequency Flat or Lo-Cut
response for additional help in obtaining the best possi-
ble microphone signal even under difficult conditions.
9-volt alkaline batteries (300 hours continuous battery
life) or by an 11-to-52 Vdc simplex (phantom) supply
from broadcast, sound-reinforcement, or recording
equipment.
mounted microphone finished in professional durable
matte-black enamel; a 7.6m (25 ft) small diameter two-
conductor shielded interconnecting cable with two
3-socket miniature Switchcraft connectors; and a stur-
dy preamplifier assembly with battery compartment,
battery On/Off switch, green LED battery-condition in-
dicator, low-frequency Flat/Lo Cut switch, and standard
3-pin professional audio connector output.
Features:
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CABLE: SHUREMlCRO
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The carefully optimized design of the SM90 includes
The SM90 is powered either by two readily available
The SM90 consists of a small, rugged, surface-
Wide flat frequency response for faithful sound
reproduction across the audio spectrum
Switch-selectable 12 dB/octave low-frequency cutoff
permits tailoring response to suit conditions
Omnidirectional polar pattern for pickup in full
hemisphere surrounding microphone mounting sur-
face
High sensitivity and high signal-to-noise ratio
Very low distortion and high output clipping level
Battery or simplex powering: uses standard 9-volt
alkaline batteries: accepts wide range of simplex
voltages - 11 to 52 Vdc
Low susceptibility to RFI, electrostatic and electro-
magnetic hum
Extremely rugged construction of both microphone
and preamplifier for outstanding reliability
Low profile and matte black finish for unobtrusive
appearance on-camera or onstage; on floor, table,
ceiling, wall, or lectern
Usable over very wide range of temperature and
humidity
Printed in U.S.A.
Patent Pending