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 hand- held/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. |
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PHONE (312) 866-2200 |
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TELEX: 4330191 |
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FAX (312) 866-2279 |
SM15 MODEL MICROPHONE CONDENSER WORN-HEAD UNIDIRECTIONAL
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).
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)
TYPICAL FREQUENCY RESPONSE
FIGURE 2
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)
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)
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