Shure SM81-LC Unidirectional Condenser Instrument Microphone Designed For Studio Recording & Broadcasting

The Shure SM81 is a high-quality, unidirectional condenser microphone designed for studio recording, broadcasting, and sound reinforcement. Its wide frequency response, low noise characteristics, and low RF susceptibility have made it a standard for applications involving acoustic instruments, especially guitar, piano, and cymbals.

The SM81 is ruggedly constructed. It operates on phantom power and performs over a wide range of temperatures and humidity conditions. It is furnished with a swivel adapter, attenuator-switch lock, foam windscreen, and case for carrying and storage. Other accessories are available.

The Shure SM81-LC comes with a windscreen but no cable. Phantom power required.

Features:

• 0 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

Specifications:

• Type: Condenser (electret bias)
• Frequency Response: 20 to 20,000 Hz
• Polar Pattern: Cardioid (unidirectional) response-uniform with frequency, symmetrical about axis
• Output Impedance: Rated at 150 ohms (85 ohms actual)
  Recommended minimum load impedance: 800 ohms (May be used with loads as low as 150 ohms with reduced clipping level)
• Output Configuration and Connector: Balanced, transformer-coupled output; male XLR connector
• Sensitivity (at 1,000 Hz): Open Circuit Voltage: -45 dBV/Pascal (5.6 mV (1 Pascal = 94 dB SPL)
• Clipping Level (at 1,000 Hz): 800 ohm Load:
  -4 dBV (0.63 V)
  150 ohm Load: -15 dBV (0.18 V)
• Total Harmonic Distortion: Less than 0.5% (131 dB SPL at 250 Hz into 800 ohm load)
• Maximum SPL (at 1,000 Hz):
  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)
• Hum Pickup: -3 dB equivalent SPL in a 1 mOe field (60 Hz)
• Self-Noise (equivalent sound pressure levels; measured with true rms voltmeter):
  16 dB typical, A-weighted
  19 dB typical, weighted per DIN 45 405
• Signal-to-Noise Ratio: 78 dB (IEC 651)* at 94 dB SPL
  *S/N ratio is difference between 94 dB SPL and product’s equivalent self noise (SPL A-weighted).
• Overvoltage and Reverse Polarity Protection: Max. external voltage applied to pins 2 and 3 with respect to pin 1: +52 Vdc
• Reverse polarity protection: 200 mA max. (diode-clamped)
• Polarity: Positive pressure on diaphragm produces positive voltage on pin 2 relative to pin 3
• Cartridge Capacitance: 54 pF
• Low Frequency Response Switch Positions: Flat; -6 dB/octave below 100 Hz; -18 dB/octave below 80 Hz
• Attenuator Switch Positions (Lockable): 0 or -10 dB
• Power: Supply Voltage: 11 to 52 Vdc, positive, pins 2 and 3
  Current Drain: 1.2 mA max.
• Environmental Conditions:

  Temperature:

• Storage: -29 degrees to 74 degrees C (-20 degrees to 165 degrees F)
• Operating: -6.7 degrees to 49 degrees C (20 degrees to 120 degrees F)

  Humidity:

• Storage 0 to 95% relative humidity at room temperature (72 degrees to 80 degrees F, 22 degrees to 27 degrees C)
• Case: Steel construction with vinyl metallic paint finish and stainless steel screens
• Weight:
  Net: 230 grams (8 oz)
  Packaged: 740 grams (1 lb 10 oz)