Shure SM27 

Multi-Purpose Microphone

The Shure^® SM27 is a rugged and versatile large-diaphragm, side-address cardioid microphone. Low self-noise and extended frequency response picks up vocal and instrument nuances with clarity. Durable Shure construction features three separate mesh layers that reduce wind and breath noise. Equally comfortable on the stage or in the studio.

Features

• Cardioid polar pattern—the most commonly used pattern for both studio and live applications
• 1 inch, externally biased, ultra-thin, 2.5 μm, 24 Karat gold-layered, low mass, Mylar^® diaphragm provides superior transient response
• Class A, discrete, transformerless preamplifier for transparency, extremely fast transient response and no crossover distortion, while minimizing harmonic and intermodulation distortions
• Premium electronic components and gold-plated internal and external connectors
• Subsonic filter eliminates rumble from mechanical vibration below 17 Hz
• Switchable 15 dB pad for handling extremely high sound pressure levels (SPLs)
• 3-position switchable low-frequency filter helps reduce unwanted background noise or counteract proximity effect
• Integrated three-stage “pop” protection grille reduces plosives and other breath noise
• Internal shock mount reduces handling and stand noise

Variations

SM27-LC: Includes a padded carrying bag and low-profile stand mount.

SM27-SC: Includes a rubber-suspension shock mount and velveteen pouch.

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.

Positioning the Microphone

The front of the microphone is marked by the Shure logo. Position this side toward the sound source.

Selecting Low-Frequency Response

A three-position switch on the back of the microphone lets you adjust the low-frequency response. Use the low-frequency filter to reduce wind noise, room noise, or proximity effect.

Flat response. Provides the most natural sound in most applications.

Low frequency cutoff. Provides an 18 dB-per-octave cutoff at 80 Hz. Helps eliminate floor rumble and low-frequency room noise from heating and air conditioning systems. This setting may also be used to compensate for proximity effect or to reduce low frequencies that make an instrument sound dull or muddy.

Low frequency rolloff. Provides a 6 dB-per-octave rolloff filter at 115 Hz. Use this to compensate for proximity effect or to reduce low frequencies that could make an instrument sound dull or muddy.

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

Condenser (externally biased)

Frequency Response

20 to 20,000 Hz

Polar Pattern

Cardioid

Output Impedance

140 Ω

Sensitivity

at 1kHz,open circuit voltage: -37 dBV/Pa[1]

Maximum SPL

1 kHz at 1% THD[2]

2500 Ω load: 138 dB (152 dB, PAD ON)

1000 Ω load: 133 dB (147 dB, PAD ON)

Signal-To-Noise Ratio[3]

84.5  dB

Dynamic Range

at 1kHz

2500 Ω load: 128 dB

1000 Ω load: 123 dB

Common Mode Rejection

20 Hz to 20 kHz: >50  dB

Clipping Level

20 Hz to 20 kHz, at 1% THD

2500 Ω load: 7 dB

1000 Ω load: 1 dB

Self Noise

equivalent SPL, A-weighted, typical: 9.5  dB

Polarity

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

Weight

642 g(22.6 oz.)

Switch

Connector

Three-pin professional audio (XLR), male, balanced

Power Requirements

48 V DC phantom power, 5.4  mA

[1] 1 Pa=94 dB SPL

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

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

Typical Frequency Response

Typical Polar Patterns

Overall Dimensions

Accessories

Furnished Accessories

SM27-LC

SM27-SC

Optional Accessories

Replacement Parts

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