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.

AK30 is a diffuse-field equalized pressure transducer with a free-field treble boost (approx. 7dB at 10kHz). The frequency response in the diffuse sound field is flat up to 10kHz.