AK... active capsules are part of the variable miniature microphone system. Together with the KM100 output stage AK... active capsules form a complete microphone. AK30 and KM100, for example, make up the KM130.

AK50 is a pressure gradient transducer with a hypercardioid characteristic. Attenuation of sound incidence from the side or rear is approximately 10dB. Minimum sensitivity occurs at an angle of about 120.