JM4001 microphone is a pre-polarization microphone, being used for measuring the real sound pressure distortionlessly before being put into the sound field. Due to the existence of the microphone in the sound field, JM4001 microphone will influence the sound field and change the location of high frequency sound field.
Free-field microphone aims to adjust the frequency response of the microphone, so as to correct deviation in the high frequency sound field. JM4001 microphone completely meets the following requirements: IEC 61094-4 and GBT 20441-4.