Cardioid condenser instrument microphone offers a wide frequency response and low self-noise. Features include flat response curve, low noise and high output clipping level, low distortion over a range of load impedances, and low RF susceptibility.

  • 20 Hz to 20 kHz frequency response
  • Flat response curve for accurate reproduction of sound sources
  • Low noise and high output clipping level
  • Low distortion over a wide range of load impedances
  • Cardioid polar pattern, uniform with frequency and symmetric about axis, providing maximum rejection and minimum coloration of off-axis sounds
  • Low RF susceptibility
  • Selectable low-frequency response: flat, 6 or 18 dB/octave rolloff
  • 0 dB/10 dB lockable attenuator switch
  • Phantom powering (DIN 45 596 voltages of 12 to 48 Vdc)
  • Rugged steel construction for durability
  • Field-usable over wide range of temperature and humidity conditions

What is the SM81 best suited to?

The SM81 is the perfect choice for a professional musician or sound engineer who is looking to mic up acoustic instruments such as acoustic guitar, piano and cymbals. It can ideally be used on stage and because of its high quality is also at home in the recording studio. 

What characteristics can I expect when using an SM81?

The SM81 has a flat response curve for accurate reproduction of the sound source and can also be modified via a bass roll off switch. The 0dB/10bB lockable attenuator switch gives you even more flexibility when miking up loud sound sources and it has a cardioid polar pattern which isolates the main sound source while minimizing handling noise.

Amount Part Title
1 swivel adapter
1 attenuator-switch lock
1 foam windscreen
1 carrying case

Technical specifications

230 g
Height x Width x Depth:
212.0 × 23.5 × 23.5 mm
Frequency Response:
20 Hz – 20 kHz
Frequency Response:
-45.00 dBV/Pa – 5.60 mV/Pa
Equivalent Selfnoise:
16 dB(A)
Sound Pressure:
800 ohm load: 136 dB (attenuator at 0) 146 dB (attenuator at -10), 150 ohm load: 128 dB (attenuator at 0) 138 dB (attenuator at -10)
Transducer Type:
Polar Pattern:
Switchable low cut:
3 Pin XLR
Interchangeable Capsule:
Main Functionality:
Headphone Output:
Requires Phantom Power:
11 to 52 VDC
Frequency Response Curve Image:
Shure Condenser Instrument Microphone                    Frequency Response Curve Image

Further Technical Specifications

Further Specs:
  • Impedance:
    • Rated at 150 ohms (85 ohms actual)
  • Output Clipping Level:
    • 800 ohm Load: -4 dBV (0.63 V)
    • 150 ohm Load: -15 dBV (0.18 V)
  • Hum Pickup
    • -3 dB equivalent SPL in a 1 mOe field (60 Hz)