The Sanken CO-100K is the first 100kHz microphone in the world designed for actual professional recording, not for measurement purposes. A revolutionary microphone designed with NHK’s Science & Technical Research Laboratories, it is Sanken's response to those enthusiastic engineers who wish to record frequencies as high as 100kHz. After rigorous test recordings, it was found that this microphone is especially suited for classical music, acoustic instrument and sound effect recording.
Prominent owners have used two CO-100K in stereo pairs, overall string sections, and in four and five channel arrays for surround and front of orchestra.

Within the conventional "audible frequency" band of 20Hz to 20kHz the performance is exemplary, and clearly different. But the CO-100K also provides the opportunity to experience musical sounds far beyond the typically accepted upper frequency limit. The CO-100K is a new step in microphone technology, providing new realms of musical detail and nuance that has never before been possible.