Shure SM15 User Guide

MODEL SM15

UNIDIRECTIONAL HEAD-WORN CONDENSER MICROPHONE

MODEL SM15

UNIDIRECTIONAL HEAD-WORN
CONDENSER MICROPHONE

The Shure Model SM15 is a unidirectional headworn
electret condenser microphone primarily designed
for high-quality sound reinforcement applications. Its
high output and excellent acoustic properties also
make it a good choice for use in broadcasting, talk­back, paging, communications, and data entry. The
SM15 is one of the few headworn microphones availa­ble today that closely approximates the best in hand­held/stand-mount vocal microphones.

The SM15’s smooth, natural voice frequency
response makes it ideal for drummers, keyboard art­ists and other musicians requiring a vocal microphone
with all the qualities of a hand-held unit-the SM15
can be used under noisy conditions without loss or
masking of voice signals.

A small, lightweight, rugged and reliable unit, the
SM15 has provisions for mounting to a supplied head­band with cushioned arms. The dual steel headband
holds securely without causing discomfort for active
microphone users. A pivot housing permits the micro­phone boom to be moved 20° in any direction, and the
distance between the microphone and pivot can be
changed by up to 89 mm (3-1/2 in.).

The SM15’s amplifier is constructed of high-impact
ARMO-DUR®, making it compact, lightweight, and
extremely rugged. It can easily be clipped to a belt or
waistband, or slipped into a pocket. It is powered by a
readily available 9-volt battery or by phantom power
from an external source providing 5-52 Vdc (such as a
Shure PS1A power supply or M267 or M268 micro­phone mixer). The amplifier incorporates extensive
RF and hum shielding to reduce the effects of electro­magnetic and electrostatic interference. Connections
between the microphone and amplifier are made
through a miniature 3-pin connector.

The SM15 is supplied with a windscreen to protect
against wind noise and explosive breath sounds, and a
foam-lined carrying/storage case.

Features

• Close-talk operation and unidirectional polar pat­tern for effective noise reduction

• High sound pressure level capacity

• Smooth, natural frequency response, tailored for

voice

• Low distortion and wide dynamic range characteris­tics under various load impedances

• Wide-range phantom powering accepts all commonly
used voltages; can also be battery-powered

• Acoustically isolated for maximum feedback freedom

• Locking adjustment knob permits 20° boom pivot

in any direction. Boom mounts on either side of
headband

• Boom length adjustment through 89 mm (3-1/2 in.)

• Dual headband design plus serrated arms minimize

accidental movement

• Lightweight design prevents user fatigue

• No interference with eyeglasses

• Ruggedly constructed of stainless steel, aluminum

and high-impact thermoplastic

• Usable over wide range of temperature and humid­ity conditions

• Amplifier assembly can be pocketed, strapped to
body, or clipped to belt or waistband

ASSEMBLY

Assemble the SM15 for use as follows:

1. Twist the lower headband arms 90° so they are

perpendicular to the headband. As supplied, the
retaining clip is positioned for left side operation as
shown in Figure 1. For right side usage (see photo),
remove the retaining clip and attach it to the other
(unused) hole in the headband arm so the screw is
at the top.

2. Snap the microphone pivot housing into the retaining

clip with the pivot adjustment knob upward and the
microphone toward the front. Loosen the pivot adjust­ment knob, position the boom so that the micro­phone is near where the side of the mouth will be,
and tighten the pivot adjustment knob.

3. Place the assembled microphone on the user’s head

and pull the headband arms downward until they
rest against the head just over the ears.

4. Loosen the pivot adjustment knob and position the

microphone as close as possible to the corner of
the mouth. IMPORTANT: For optimum close-talking
operation, the microphone should be less than 25mm
(1 in.) from the corner of the mouth. Be sure to
position the microphone at the corner (not the cen­ter) of the mouth to eliminate explosive breath
sounds (“pop”). Tighten the adjustment knob.

222 HARTREY AVE., EVANSTON, IL 60202-3696 U.S.A. • PHONE [phone] • TELEX: 4330191 • FAX [phone]

Copyright 1987. Shure Brothers Inc. Printed in U.S.A.
27A2371 (GB) U.S. Patent 4,039,765

5. Connect the SM15 microphone cable to the ampli­fier assembly.

6. Insert a fresh 9-volt battery in the amplifier battery
compartment (see Batteries section) and connect
the amplifier 3-pin XLR connector to the mixer input
connector, or phantom-power the SM15 by con­necting the amplifier (without battery) to a micro­phone powersupply providing 5 to 52 Vdc phantom
voltage. This can be a separate phantom power
supply, or a mixer or amplifier with provisions for
phantom powering (see Phantom Powering section).

7. Place the amplifier assembly in the desired position
(see Amplifier Mounting section).

Polar Pattern

Cardioid (unidirectional) response–uniform with
frequency, symmetrical about axis (see Figure 3)

TYPICAL POLAR PATTERNS

FIGURE 3

Output Impedance

Rated at 150 ohms (95 ohms actual)
Recommended minimum load impedance: 800 ohms
(may be used with loads as low as 150 ohms with
reduced clipping level)

SM15 POSITIONED FOR LEFT SIDE OPERATION

FIGURE 1

SPECIFICATIONS

Type

Condenser (electret bias)

Frequency Response (at 76 mm–3 in.)

50 to 15,000 Hz (see Figure 2)

Output Level (close-talked at 1,000 Hz)

Open Circuit Voltage

–40.5 dB (0.9 mV) at 610 mm (24 in.)
–39 dB (1.1 mV) at 10 mm (0.39 in.)

(0 dB = 1 volt per 100 microbars)

Clipping Level (at 1,000 Hz)

800-ohm Load................. –13 dB (0.22V)

150-ohm Load................ –27 dB (0.045V)

Total Harmonic Distortion

Less than 1% (138 dB SPL at 1,000 Hz into 800-ohm

load)

Maximum SPL

141 dB with 800-ohm load

130 dB with 150-ohm load

Hum Pickup

Less than or equal to 0 dB equivalent SPL in a 1

millioersted field (60 Hz)

Output Noise (equivalent sound pressure levels; meas­ured with true rms voltmeter)

32 dB typical, A-weighted

38 dB typical, weighted per DIN 45 405

Dynamic Range

109 dB (maximum SPL to A-weighted noise level)

TYPICAL FREQUENCY RESPONSE

FIGURE 2

Signal-to-Noise Ratio

62 dB (IEC 651) at 94 dB SPL

Phasing

Positive pressure on diaphragm produces positive

voltage on pin 2 relative to pin 3

Power

Battery: 9 Vdc (type 1604A, alkaline recommended);

0.33 mA current drain; approximately 1600 hours

continuous use with fresh battery