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.

• 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

• Type Condenser (electret bias)
• Frequency Response 20 to 20,000 Hz
• Polar Pattern Cardioid (unidirectional) responseâ?"uniform with frequency, symmetrical about axis
• Impedance 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 Level 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 - Load .4 dBV (0.63 V) 150 - Load .15 dBV (0.18 V)
• Total Harmonic Distortion Less than 0.5% (131 dB SPL at 250 Hz into 800 . load )
• Connector Output Configuration and Connector Balanced, transformer-coupled output; male XLR connector
• Polarity Positive pressure produces positive voltage on pin 2 relative to pin 3
• Dimensions 212 mm / 8.34 in./ in length, and 23 1/2 mm / 0.92 in./ in diameter. ( Handle diameter: 20.1 mm / 5/32 in. )
• Weight 230 grams (8 oz)
• Power Requirements Supply Voltage 11 to 52 Vdc, positive, pins 2 and 3 / Current Drain 1.2 mA max. The SM81 requires phantom power. This may be supplied to the microphone by a mixer, preamplifier or console with built-in phantom power or from an external power supply (such as the Shure model PS1A). Phantom power sources providing between 11 and 52 Vdc are suitable.

• Acoustic Guitar
• Acoustic Bass
• Strings
• Piano
• Woodwinds
• Orchestra
• Cymbals
• Live Recording
• Ensemble Vocals

• 1 x Shure SM81 Condenser Microphone
• 1 x Shure Swivel Adapter
• 1 x Shure Attenuator-switch Lock
• 1 x Shure Foam Windscreen
• 1 x Carrying Case
• 2 Year Warranty