The MK 22 has been developed for use as a spot microphone. It unites the strengths of the MK 4 and MK 21 capsules. Its directionality is only slightly less than that of the MK 4 cardioid, while its sonic character is reminiscent of the MK 21 wide cardioid. Its directivity is essentially constant throughout the frequency range. Its inherent low-frequency response is somewhat more pronounced than that of the cardioid, while proximity effect is somewhat less.

MK 22 capsules are well suited for use as stereo pairs. The well-known “Williams curves” indicate the possibilities for ideal miking arrangements. The curves shown below for the Open Cardioid give the stereophonic recording angle as a function of the angle between two microphones and the distance between their capsules.
One possible arrangement, for example, would be a distance of 21 cm with a 110° angle between the microphones.
The STC 22 mounting bar facilitates the use of this arrangement with two MK 22.

Williams curves of the MK 22 (with kind permission of Michael Williams)

STC 22

User Guide