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

• 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
• Rugged steel construction for durability
• 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

Technical Specs

• Type: Condenser (electret bias)
• Frequency Response: 20 to 20,000 Hz
• Polar Pattern: Cardioid (unidirectional) response-uniform with frequency, symmetrical about axis
• Output Configuration: Balanced, transformer-coupled output; male XLR connector
• Signal-to-Noise Ratio: 78 dB (IEC 651)* at 94 dB SPL
• Polarity: Positive pressure on diaphragm produces positive voltage on pin 2 relative to pin 3
• Power Supply Voltage: 11 to 52 Vdc, positive, pins 2 and 3
• Case: Steel construction with vinyl metallic paint finish and stainless steel screens