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MODEL SM98
UNIDIRECTIONAL CONDENSER MICROPHONE
GENERAL
The SM98 is a miniature electret condenser microphone
with a unidirectional (cardioid) pickup pattern. A smooth
wide frequency response from 40 to 20,000 Hz allows the
microphone to be extremely well adapted to pick up all
kinds of musical instruments. A detachable 4.6m (15 ft)
cable with Switchcraft Tini Q.G. connectors and a battery
or simplex (phantom) powered preamplifier are supplied
with the microphone. A windscreen is provided for outdoor use, and a swivel adapter is supplied for conventional
microphone stand or goose neck mounting.
The unidirectional pattern of the SM98 discriminates
against sounds coming from the rear, permitting higher
gain before feedback in sound reinforcement applications. Because of its uniform cardioid pattern extending
out to 20,000 Hz, the microphone can be used for pickup of
a particular instrument in an ensemble or orchestra, minimizing the need for isolation booths or barriers. A very
high maximum sound pressure level allows use of the
SM98 with all acoustic instruments including drum kits
and other percussion as well as brass, reed, wind, string,
and keyboard instruments. The SM98 can also be used
with amplified guitars and keyboards.
The low-distortion, high-clipping-level preamplifier
provides switch-selectable Flat or Low-Cut response to
suit pickup characteristics needed for various instruments. The Low-Cut position is also useful when it is
necessary to filter out low-frequency noise from such
sources as wind noise or air conditioning equipment.
The SM98 is powered either by two readily available
9-volt alkaline batteries (300 hours continuous battery
life) or by an 11-to-52 Vdc simplex (phantom) supply from
sound reinforcement, recording or broadcast equipment.
The preamp is designed so that the battery supply will
automatically switch in should the simplex power fail.
However, no battery drain will occur as long as the simplex
voltage exceeds the battery voltage.
A series of optional accessories is available designed
exclusively for use with the SM98. These include the following: A98MK Drum Kit, a gooseneck holder for mounting the microphone directly on most drums; A98-G18, an
18-inch gooseneck for mounting the microphone on a
podium, table, or desk; A98HA, a hanging adapter permitting the microphone to be suspended from above; and
A98PF, a pop filter and locking collar kit, allowing the
SM98 to be used for speech or vocal pickup.
Features:
•
Smooth wide response for accurate sound reproduction across the entire audio spectrum
•
Symmetrical cardioid pattern, uniform with frequency
out to 20 kHz, maximizes gain before feedback, minimizes need for isolation when picking up single instruments out of a group
•
Switch-selectable 12 dB/octave low-frequency cutoff
permits tailoring response to suit particular instruments or room conditions
•
Very high SPL capability
•
Very low distortion and high output clipping level
•
Battery or simplex (phantom) powering: uses standard
9-volt alkaline batteries; accepts wide range of simplex
voltages, from 11 to 52 Vdc
•
Low susceptibility to RFI, electrostatic and electromagnetic hum
•
Rugged construction of microphone and preamplifier
for outstanding reliability
•
Detachable cable at both microphone and preamplifier
•
Usable over very wide range of temperature and
humidity
Supplied with unique swivel adapter for mounting on
•
conventional microphone stands or goosenecks
Optional accessories to increase microphone’s versa-
•
tility include: A98MK, Drum Kit; A98-G18, Gooseneck
Adapter; A98HA, Hanging Adapter; A98PF, Pop Filter
SPECIFICATIONS:
Type
Cardioid condenser (electret bias)
Frequency Response
40 to 20,000 Hz (see Figure 1)
222 HARTREY AVENUE, EVANSTON, ILLINOIS 60202-3696 U.S.A. • PHONE (312) 866-2200 • TELEX 4330191 • FAX (312) 866-2279
Copyright 1987, Shure Brothers Inc.
27A2173(GJ)
Printed in U.S.A.
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Polar Pattern
Unidirectional (cardioid), uniform with frequency,
symmetrical about axis (see Figure 2)
TYPICAL POLAR PATTERN
FIGURE
Output Impedance
Rated at 150 ohms (90 ohms actual)
Recommended minimum load impedance: 800 ohms
(May be used with loads as low as 150 ohms with
reduced clipping level)
Output Level (at 1,000 Hz)
Open Circuit Voltage . . . . . . . . . . . . . -80.0 dB (0.10 mV)
0 dB = 1V/µbar
2
Battery On/Off Switch: Move to On to power from batteries or to use batteries as backup power in case of
interruption to external power supply (no battery drain
occurs as long as simplex voltage source is greater than
battery voltage). Move to Off to prevent battery drain
when unit is not in use
LED Indicator: Green LED flashes momentarily when
switch is moved to On to indicate at least 8 hours of
battery life remaining
Flat/Lo Cut Switch: In Lo Cut position, 12 dB/octave
rolloff below 80 Hz (see Figure 1)
Cable
4.6m (15 ft) two-conductor shielded, small diameter,
interconnecting cable with 3-socket miniature Switchcraft Tini Q.G. connector on each end to mate with
microphone output connector and preamplifier input
connector
Case
Microphone: Matte black enamel brass case and stainless steel inner grille
Preamplifier: Matte black enamel die-casting
Dimensions
See Figure 3
Preamplifier Output Clipping Level (at 1,000 Hz, less than
0.1% THD)
800 ohm load . . . . . . . . . . . . . . . . . . . . . . . . .
150 ohm load
Maximum SPL (at 1,000 Hz)
800 ohm load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
150 ohm load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hum Pickup
-5 dB equivalent SPL in 1 m0e field (60 Hz)
Output Noise
34 dB SPL, A-weighted
37 dB SPL, weighted per DIN 45 405
Signal-to-Noise Ratio
64 dB re 94 dB SPL
Dynamic Range
121 dB
Phasing
Positive pressure on diaphragm produces positive
voltage on pin 2 relative to pin 3 of preamplifier output
connector
Power
Battery: Two 9-Vdc alkaline (NEMA 1604A), approximately 300 hours continuous with fresh alkaline
batteries
Simplex (Phantom) Voltage: 11 to 52 Vdc, operational
down to 9 Vdc; 1.8 mA current drain; permissible to use
simplex power with batteries in place or removed
Switches and indicator
Two recessed slide switches and green LED indicator
on top surface of preamplifier assembly
. . . . . . . . . . . . . . . . . . . . . .
0 dBV (1.0V)
-13 dBV (0.22V)
155 dB
145 dB
OVERALL DIMENSIONS
FIGURE 3
Environmental Conditions
Operating Temperature:
Storage Temperature: -29° to 74° C (-20° to 168° F)
Relative Humidity (Operating or Storage): 0 to 95%
Net Weight
Microphone: 12 grams (0.4 oz) less cable
Preamplifier: 435 grams (15.4 oz) less batteries
Furnished Accessories
Windscreen, Swivel Adapter
USING THE SWIVEL ADAPTER
To mount the SM98 in the supplied swivel adapter:
1. Mount the adapter on a microphone stand.
2. Loosen the thumbscrew at the top of the adapter.
3. Attach the microphone to the connector.
4. Slip the cable through the slot in the adapter. Slide the
connector back through the hole until the protruding
black cable-lock button is in the open slot and the
microphone stops flush with the flat on the adapter.
-18° to 57° C (0° to 135° F)
2