The Shure KSM141 is an end-addressed electret condenser microphone with a medium diaphragm and mechanically switched pattern control.

Is is nearly identical to Shure’s KSM137, which has a fixed cardioid pattern. The two mics have identical capsules; the KSM141 achieves an omnidirectional pattern by closing the acoustic vents at the rear of the mic capsule. 

Like the KSM137, the KSM141 has a 3-way pad switch (0dB, -15dB, -25dB) and a max SPL (at -25dB) of 170dB into a 5kOhm load. The mic’s self-noise rating is 14dBA.

A second 3-way switch controls the high-pass filter, which provides two levels of LF attenuation: -6dB/octave at 115Hz, or -18dB/octave at 80Hz. In addition, a nonswitched subsonic filter in the amp circuit attenuates sound below 17Hz.