Shure SM81-LC Instrument Microphone

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.

Features

• 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

Specifications

• Type: Condenser
• Frequency Response: 20 to 20,000 Hz
• Polar Pattern: Cardioid
• Sensitivity (at 1,000 Hz): Open Circuit Voltage: -45 dBV/Pascal (5.6 mV) (1 Pa = 94 dB SPL)
• Impedance: Rated at 150 ohms (85 ohms actual)
• Recommended minimum load impedance: 800 ohms
• Output Clipping Level: 800 ohm Load: -4 dBV (0.63 V), 150 ohm Load: -15 dBV (0.18 V)
• 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)
• Self-Noise: 16 dB typical, A-weighted; 19 dB typical, weighted per DIN 45 405
• Hum Pickup: -3 dB equivalent SPL in a 1 mOe field (60 Hz)
• Signal-to-Noise Ratio: 78 dB (IEC 651)* at 94 dB SPL
• 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
• Power: 11 to 52 vdc, 1.2 mA
• Case: Steel construction with vinyl metallic paint finish and stainless steel screens
• Connector: Three-pin professional audio connector (male XLR type)
• Net Weight: 230 grams (8 oz)
• Dimensions: 212 mm (7-9/16 in.) L x 23.5 mm (2 in.) W at the widest point