The KK 145 is a pressure gradient transducer with cardioid characteristic just like the KK 184. However, it has an acoustic bass roll-off in the free field and therefore suppresses LF interference (wind, structure-borne noise). Since proximity effect is a natural feature of pressure gradient microphones, the KK 145 is optimized for a flat frequency response at a recording distance of approximately 15 cm („speech cardioid“).