The KSM137 is an end-address condenser microphone with a single cardioid polar pattern. Designed for studio use, yet rugged enough for live applications, the KSM137 can withstand extremely high sound pressure levels (SPL). Its low self-noise and extended frequency response make it ideal for recording instruments.
Versatile, durable, and precise, the KSM137 is an outstanding microphone for instruments ranging from percussion to wind, strings to brass, and piano to guitar.
Highly consistent cardioid polar pattern
Ultra-thin, 2.5 micron, 24 karat gold-layered, low mass Mylar® diaphragm for superior transient response
Class A, discrete, transformerless preamplifier for transparency, extremely fast transient response, no crossover distortion, and minimal harmonic and intermodulation distortion
Premium electronic components, including gold-plated internal and external connectors
Subsonic filter eliminates low frequency rumble (less than 17 Hz) caused by mechanical vibration
Switchable 15 dB pad for handling extremely high sound pressure levels (SPLs)
3-position switchable pad (0 dB, 15 dB, and 25 dB) for handling extremely high sound pressure levels (SPLs)
3-position switchable low-frequency filter reduces background noise and counteracts proximity effect
Performance Characteristics
Extended frequency response
Exceptional reproduction of low-frequency sounds
Can withstand high sound pressure levels (SPL)
Superior common mode rejection and suppression of radio frequency interference
Common Applications
Acoustic instruments -- such as piano, guitar, drums, percussion, strings
Wind instruments -- brass and woodwind
Low frequency instruments -- such as double bass, electric bass, kick drum
Overhead miking -- drums or percussion
Ensembles -- choral or orchestral
Room ambiance pick-up -- guitar amplifier or drums
Cartridge Type
Permanently Biased Condenser
Frequency Response
20 to 20,000 Hz
Directional Polar Pattern
Cardioid
Output Impedance
150 ohms (actual)
Attenuation Switch
0 dB, 15 dB, or 25 dB attenuation
Low Frequency Response Switch
Flat; -6 db/octave below 115 Hz
-18 dB/octave below 80 Hz
Phantom Power
48 Vdc +/- 4 Vdc (IEC-268-15/DIN 45 596), positive pins 2 and 3
Current Drain
4.65 mA typical at 48 Vdc
Common Mode Rejection
>50 dB, 20 Hz to 20 kHz
Polarity
Positive pressure on diaphragm produces positive voltage on output pin 2 relative to pin 3
Dimensions and Weight
20 mm (0.8 in.) diameter, 122 mm (4.8 in.) long
100 grams (3.5 oz.)
Sensitivity (typical, at 1000 Hz; 1 Pa = 94 dB SPL)
-37 dBV/Pa
Self-noise (typical, equivalent SPL; A-weighted, IEC 651)
14 dB
Maximum SPL at 1 kHz
5000 ohm load (Attenuator on): 145 (160, 170) dB
2500 ohm load (Attenuator on): 139 (154, 164) dB
1000 ohm load (Attenuator on): 134 (149, 159) dB
Output Clipping Level*
5000 ohm load: 15 dBV
2500 ohm load: 9 dBV
1000 ohm load: 3 dBV
*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
Dynamic Range
5000 ohm load: 131 dB
2500 ohm load: 125 dB
1000 ohm load: 120 dB
Signal to Noise Ratio**
80 dB
**S/N ratio is difference between 94 dB SPL and equivalent SPL of self noise A-weighted.
