Shure SM81-LC Cardioid Condenser Instrument Microphone
Built to withstand the rigors of regular stage and studio use, the Shure SM81 unidirectional condenser microphone is a great choice for studio recording, broadcasting, and sound reinforcement. Its wide frequency response, low noise characteristics, and low RF susceptibility make it a perfect match for applications involving acoustic instruments, especially guitar, piano, and cymbals.Ruggedly constructed, the SM81 operates on phantom power and performs over a wide range of temperatures and humidity conditions. It comes with a swivel adapter, attenuator-switch lock, foam windscreen, and case for carrying and storage.Key FeaturesFrequency response.Polar pattern.Flat response curve for accurate reproduction of sound sourcesLow noise and high output clipping levelLow distortion over a wide range of load impedancesCardioid polar pattern, uniform with frequency and symmetric about axis, providing maximum rejection and minimum coloration of off-axis soundsLow RF susceptibilitySelectable low-frequency response: flat, 6 or 18 dB/octave rolloff0 dB/10 dB lockable attenuator switchPhantom powering (DIN 45 596 voltages of 12 to 48 Vdc)Rugged steel construction for durabilityField-usable over wide range of temperature and humidity conditionsSpecificationsType: Condenser (electret bias)Frequency Response: 20 to 20,000 HzPolar Pattern: Cardioid (unidirectional) response-uniform with frequency, symmetrical about axisOutput 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 connectorSensitivity (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 H: z 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 405Signal-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 VdcReverse polarity protection: 200 mA max. (diode-clamped)Polarity: Positive pressure on diaphragm produces positive voltage on pin 2 relative to pin 3Cartridge Capacitance: 54 pFLow Frequency Response Switch Positions: Flat; -6 dB/octave below 100 Hz; -18 dB/octave below 80 HzAttenuator Switch Positions (Lockable): 0 or -10 dBPower:Supply Voltage: 11 to 52 Vdc, positive, pins 2 and 3Current Drain: 1.2 mA max.Case: Steel construction with vinyl metallic paint finish and stainless steel screensWeight: 8 ounces