The directional characteristic of the MK21 lies between the omnidirectional MK2 and the cardioid MK4. The idea of combining the advantages of the cardioid and the omnidirectional characteristic was the basis for its development. In contrast to omnidirectional microphones, which tend to have a higher directivity at higher frequencies, and to small cardioid microphones, which tend to accentuate the high frequencies of laterally incident sound, the frequency has little influence on the polar pattern of the MK21 and thus on its directivity index. This means that laterally radiating sources and reverberated sound will be transmitted with the same slight alteration of the sound colour. The angle of incidence of sound is therefore not a critical factor for this type of microphone /infracardioiddirectivity particularly independent of frequency/pleasant sound image, often described as "warm"/recommended use: spot mic and main stereo mic