The nickel finish MK 21 Microphone Capsule from Schoeps comes as a matched pair, and has a directional pattern between omni and cardioid. This capsule is designed to combine the advantages of the cardioid with those of the omni. This results in a pickup pattern which blends the 2 sets of characteristics. It has full and extended low-frequency response, with less proximity effect, while picking up more room sound.
The directivity of this capsule is slightly dependent on frequency. This contrasts with omnidirectional capsules, whose directivity increases with rising frequency, and with cardioids (at least smaller ones), which tend to accentuate high frequencies that arrive at oblique angles.
This capsule has orientation that is less critical than with a cardioid, since direct sound arriving on axis and reverberant or other sounds off axis are both reproduced accurately. This lack of coloration in the off-axis pickup produces a natural sonic impression. The low directivity of this capsule type prevents it from generating large level differences for X/Y use, though M/S and near-coincident spacings are often successful.