Description
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.
Features
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
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
S/N ratio is difference between 94 dB SPL and equivalent SPL of self– noise 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
- 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
