FRANCISCO%FILIP0.LIPUC.RCCN.PT@CUNYVM.CUNY.EDU (FRANCISCO FRAGA) (04/08/91)
I would like to have some advice about a cheap microphone for use in a spectrum analyser. Basicaly what is needed is a calibrated micro with good extension in the bass frequencies. If the reponse is known one can always correct for non linearity. I have seen that the reponse of most available micros (even some expensive ones) falls bellow 80Hz making them unsuitable for this purpose. For a spectrum analyser a micro should at less reach 30Hz within a reasonable -6 dB. I have been told that some cheap electret micros from AudioTechnica can be used for this purpose but my source was unable to give me any references. The sinal from this micro is amplified, filtered and the output is sampled by a 12 bit ADC connected to an IBM compatible AT computer. The digitized samples are processed by FFT using MathCad or some other software. ........................................................ Francisco A. F. Fraga Dept. Physics Univ. Coimbra 3000 Coimbra PORTUGAL tel. 351-39-34668 fax 351-39-29158 FRANCISCO@FILIP0.LIPUC.RCCN.PT