Shure SM137

Instrument Microphone

The Shure^® SM137 is a versatile, flat-response cardioid probe microphone with an ultra-thin diaphragm. Its frequency response combines smooth high-end and tight, controlled low-end. A 15 dB pad provides natural, consistent sound reproduction in both acoustic and high-volume performance applications.

Features

• Cardioid polar pattern to reduce the pickup of unwanted sounds
• Ultra-thin, 2.5 μm 24 karat gold-layered, low mass Mylar^® diaphragm for superior transient response
• Class A, discrete, transformerless preamplifier for transparency, extremely fast transient response, no crossover distortion, and minimal harmonic and intermodulation distortion
• Premium electronic components, including gold-plated internal and external connectors
• Two-position switchable pad (0 dB and 15 dB) for handling extremely high sound pressure levels (SPLs)

Performance Characteristics

• Extremely uniform polar response
• Extended frequency response
• Minimal self-noise
• Exceptional low-frequency reproduction
• Able to withstand high SPLs
• High output level
• No crossover distortion
• Superior common-mode rejection and suppression of radio frequency interference (RFI)

Applications

• Brass and woodwind instruments
• Orchestras, choirs, and wind ensembles
• Overhead miking of drums and percussion instruments
• Close-miking of acoustic instruments such as piano, guitar, violins, drums, and percussion
• Low-frequency instruments such as double bass and kick drum
• Electric guitar and bass amplifiers
• Vocals and speech
• Room ambience

  Note: Sound quality is strongly affected by microphone location and room acoustics. To achieve the best overall sound for a particular application, it may be necessary to experiment with microphone placement and room treatments.

Mounting the Microphone

Use the supplied microphone mount with floor or boom stands. Visit www.shure.com for more mounting options:

• To reduce the pickup of unwanted low-frequency mechanical vibrations, use an isolating shock mount.
• For stereo applications, use the optional Shure A27M Stereo Microphone Adapter.

Setting Attenuation

The attenuation switch lets you reduce the signal level without altering the frequency response. This can prevent extremely loud sounds from overloading the microphone.

Integral Pop Filter

The microphone grille consists of 3 separate mesh layers that act as an integral pop filter. This helps reduce wind and breath noise. Depending on the performer, an external pop-protection screen or windscreen may be necessary when close-miking vocalists.

Load Impedance

Maximum SPL capability, output clipping level, and dynamic range vary with the input load impedance of the preamplifier to which you connect the microphone. Shure recommends a minimum input load impedance of 1000 Ω. Most modern microphone preamplifiers meet this requirement. Higher impedance results in better performance for these specifications.

Power Requirements

This microphone requires phantom power and performs best with a 48 Vdc supply (IEC-61938). However, it will operate with slightly decreased headroom and sensitivity with supplies as low as 11 Vdc.

Most modern mixers provide phantom power. You must use a balanced microphone cable: XLR-to-XLR or XLR-to-TRS.

Specifications

Type

Electret Condenser

Frequency Response

20 to 20,000 Hz

Polar Pattern

Cardioid

Output Impedance

150 Ω (actual)

Sensitivity

(at 1 kHz, open circuit voltage): -41 dBV/Pa[1]

Maximum SPL

(1 kHz at 1% THD)

1000 Ω load: 139 dB (154 dB, PAD ON)

2500 Ω load: 144 dB (159 dB, PAD ON)

Signal-To-Noise Ratio

(Ref. 94 dB SPL at 1 kHz): 75 dB[2]

Dynamic Range

(at 1 kHz)

1000 Ω load: 120 dB

2500 Ω load: 125 dB

Common Mode Rejection

(10 Hz to 100 kHz): >50  dB

Clipping Level

(20 Hz to 20 kHz, at 1% THD[3])

1000 Ω load: 3 dBV

2500 Ω load: 9 dBV

Self Noise

(typical, equivalent SPL, A-weighted): 19 dB

Attenuator Switch

-15 dB

Polarity

Positive pressure on diaphragm produces positive voltage on pin 2 with respect to pin 3

Net Weight

195 g (6.9oz.)

Connector

Three-pin professional audio (XLR), male

Power Requirements

48 V DC phantom power, 5.2  mA

[1] 1 Pa=94 dB SPL

[2] S/N ratio is difference between 94 dB SPL and equivalent SPL of self noise, A-weighted

[3] THD of microphone preamplifier when applied input signal is equivalent to cartridge output at specified SPL.

Overall Dimensions

Typical Frequency Response

Typical Polar Patterns

Accessories

Storage Case

Windscreen

Microphone Clip

Furnished Accessories

Optional Accessories

Certifications

This product meets the Essential Requirements of all relevant European directives and is eligible for CE marking.

The CE Declaration of Conformity can be obtained from: www.shure.com/europe/compliance

Authorized European representative:

Shure Europe GmbH

Headquarters Europe, Middle East & Africa

Department: EMEA Approval

Jakob-Dieffenbacher-Str. 12

75031 Eppingen, Germany

Phone: 49-7262-92 49 0

Fax: 49-7262-92 49 11 4

Email: info@shure.de