The KSM137/SL  from Shure is a cardioid condenser studio microphone designed for instrument recording and sound reinforcement. The KSM137/SL offers a wide 20 Hz to 20 kHz frequency response making it a flexible microphone for a variety of applications. The KSM137/SL features a cardioid element and permanently biased transducer design resulting in clean, accurate signal reproduction and frequency response. The transformer-less, class-A output circuitry provides a noise free output signal path while maintaining high gain levels. The tight cardioid pattern is effective in attenuating off-axis signal due to room ambiance, instruments, monitor noise etc.
 
There is a 3-position low frequency roll-off switch, eliminating low frequency rumble noise and counteracting proximity effect. The KSM137/SL handles high sound pressure levels and features a 3-position pad switch providing attenuation at 0 dB, 15 dB and 25 dB. This allows confident miking of instruments high in transient response such as drums, percussion, and brass. the microphone is suitable for piano, strings, guitar, and woodwind as well.
 
The Features
Cardioid Pattern
- The cardioid polar pattern is effective in attenuating off-axis signal due to room ambiance, instruments, monitor noise etc.
Class-A Transformer-Less Circuitry
- The transformer-less, class-A output circuitry provides a noise free output signal path while maintaining high gain levels.
3-Position Low Frequency Roll-Off Switch
-The KSM137/SL provides flexible low frequency attenuation, eliminating low frequency noise and rumble.
3-Position Pad Switch
- The 0, 15, and 25 dB Pad switch adds greater SPL handling allowing the microphone to withstand high audio levels without distortion.
Wide Frequency Response
- The microphone offers a wide 20 Hz to 20 kHz frequency response making it a flexible microphone for a variety of applications.