Setup: Shure SM137 Instrument Microphone Instruction Guide

Shure SM137 Instrument Microphone: Comprehensive Product Manual

Introduction to the Shure SM137 Instrument Microphone

The Shure SM137 Instrument Microphone is a professional-grade cardioid condenser microphone designed for capturing natural sound reproduction in both acoustic and high-volume performance settings. Featuring an ultra-thin diaphragm, it delivers a smooth high-end response paired with tight, controlled low-end frequencies, making it ideal for miking instruments like acoustic guitars, cymbals, strings, piano, drums, and world instruments such as tabla or sitar. Its transformerless Class-A preamplifier ensures low self-noise and exceptional clarity, while the built-in 15dB pad handles high SPL sources up to 165dB, providing consistent performance across diverse applications.

Key benefits include a flat frequency response from 20Hz to 20kHz, a cardioid polar pattern for excellent off-axis rejection, and rugged construction built like a tank for live and studio use. Professionals, home studio owners, and live sound engineers appreciate its versatility for instrument miking, overheads, and even voiceovers. The Shure SM137 Instrument Microphone comes with a swivel adapter and zippered pouch, requiring 48V phantom power and drawing just 5.2mA.

Targeted at musicians and audio engineers seeking reliable condenser instrument microphones, it's perfect for recording drums, grand pianos, or acoustic ensembles. Estimated price range is $99-$150, widely available at retailers like Guitar Center, Sweetwater, and Shure's official site with free shipping on orders over $50 and a 30-day return policy. This small-diaphragm condenser stands out for its value, combining Shure's legendary durability with pro-level sound quality for live sound reinforcement and studio tracking.

Specifications

• Type: Electret condenser
• Frequency response: 20 to 20,000 Hz
• Polar pattern: Cardioid
• Output impedance: 150 Ω
• 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.
• Weight: 195 g (6.9 oz.)
• Connector: Three-pin professional audio (XLR), male

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

 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.

Setup

• 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.

Accessories

• Zippered Carrying Bag

• Windscreen

• Microphone Clip

Troubleshooting the Shure SM137 Instrument Microphone

Common issues with the Shure SM137 Instrument Microphone often stem from setup or environmental factors. If no sound is produced, verify 48V phantom power is active on your interface or mixer, as the mic requires 48VDC ±4VDC. Check XLR cable connections and ensure the attenuator switch is set to 0dB for low SPL sources. Low output? Confirm sensitivity at -41dBV/Pa and test with a 150Ω load; use the 15dB pad for SPL over 139dB to prevent clipping.

Hum or noise (self-noise typically 19dB A-weighted) may indicate ground loops—use balanced XLR cables and isolate from AC units or hard drives. For distortion, position the cardioid pattern away from off-axis bleed and maintain >50dB common mode rejection. Preventive measures: Store in the provided pouch, avoid drops (net weight 195g), and clean the grille gently with a dry cloth.

Shure offers a 2-year warranty; register at shure.com for support. Contact Shure tech support via their website or call 1-800-323-8359 for expert assistance. No specific error codes apply, but reference specs like signal-to-noise ratio of 75dB for diagnostics.

Pros and Cons of the Shure SM137 Instrument Microphone

Pros

• Exceptional clarity and response: Ultra-thin diaphragm provides smooth highs and tight bass across 20-20kHz, ideal for acoustic guitar and cymbals.
• High SPL handling: Up to 165dB with pad, perfect for loud drums or pianos without distortion.
• Low noise and rejection: 19dB self-noise and> 50 dB CMR make it great for untreated home studios.
• Durable build: Rugged design withstands live use, includes a swivel adapter.
• Value for money: Affordable at $99-$150, outperforms many pricier small-diaphragm condensers.

Cons

• Limited accessories: Only pouch and adapter; no clip or stand included.
• Phantom power required: Not passive; needs a 48V supply.
• Less low-end warmth: Flat response suits instruments but may need EQ for vocals compared to large-diaphragm mics.

Compared to AKG C451 (more expensive, brighter) or Audio-Technica AT2021 (budget alternative, higher noise), the Shure SM137 Instrument Microphone excels in balanced performance and reliability.

Customer Reviews of the Shure SM137 Instrument Microphone

Users rave about the Shure SM137 Instrument Microphone, averaging 4.8/5 stars across sites like Crutchfield and Guitar Center. "Nice general purpose mic that sounds great in home studios and is built like a tank. Great for instruments, voiceovers, and overheads," praises one reviewer, highlighting its off-axis rejection and clean sound. Another calls it a "hidden treasure" for smooth, warm voice capture despite its instrument focus, with excellent isolation from hum.

Common praises: Durability, low noise for acoustics, and value. Complaints are minor, like needing a pop filter for vocals or extra mounts. Most recommend it for pros and hobbyists: "Flattering and forgiving—buy multiple!" Frequent issues like phantom power setup are easily resolved. Ideal for drum overheads and piano miking, it's a top pick for reliable condenser instrument microphones.