SM Series Condenser Instrument Microphone

The SM137 is a versatile, flat-response cardioid condenser probe microphone.<br/><br/>The SM137 has an ultra-thin diaphragm for a frequency response that combines a smooth high-end with a tight, controlled low-end and a 15db pad for natural sound reproduction in both acoustic and high volume performance applications.<br/><br/>Cartridge Type<br/>Permanently Biased Condenser<br/><br/>Frequency Response<br/>20 to 20,000 Hz<br/><br/>Directional Polar Pattern<br/>Cardioid<br/><br/>Output Impedance<br/>150 ohms (actual)<br/><br/>Attenuation Switch<br/>0 dB or 15 dB attenuation<br/><br/>Phantom Power<br/>48 Vdc +/- 4 Vdc<br/>(IEC-268-15/DIN 45 596), positive pins 2 and 3<br/><br/>Current Drain<br/>5.2 mA typical at 48 Vdc<br/><br/>Common Mode Rejection<br/>>50 dB, 20 Hz to 20 kHz<br/><br/>Polarity<br/>Positive pressure on diaphragm produces positive voltage on output pin 2 relative to pin 3<br/><br/>Dimensions and Weight<br/>24 mm (0.950 in.) diameter<br/>162 mm (6.375 in.) long<br/>195 grams (6.9 oz.)<br/><br/><br/>Sensitivity (typical, at 1000 Hz; 1 Pa = 94 dB SPL)<br/>-41 dBV/Pa<br/><br/>Self-noise (typical, equivalent SPL; A-weighted (IEC 651))<br/>19 dB<br/><br/>Maximum SPL@ 1000 Hz<br/>5000 ohms load (Attenuator on): 150 (165 dB)<br/>2500 ohms load (Attenuator on): 144 (159) dB<br/>1000 ohms load (Attenuator on): 139 (154 dB)<br/><br/>Output Clipping Level*<br/>5000 ohms load: 15 dBV<br/>2500 ohms load: 9 dBV><br/>1000 ohms load: 3 dBV<br/>*20 Hz to 20 kHz; THD < 1%. THD of the microphone preamplifier when applied input signal is equivalent to the cartridge output at specified SPL.<br/><br/>Dynamic Range (Attenuator On)<br/>5000 ohms load: 133 (136) dB<br/>2500 ohms load: 128 (130 dB)<br/>1000 ohms load: 122 (125) dB<br/><br/>Signal to Noise Ratio**<br/>75 dB<br/>**S/N ratio is difference between 94 dB SPL and equivalent SPL of self-noise A-weighted.<br/><br/>