Frequency response analysis of microphone preamplifiers in the audible and ultrasonic regime

摘要

This report presents an investigation on the frequency response of two types of electret microphone preamplifiers currently in use with SotonArray, Southampton University's wind tunnel microphone array system. The investigation is presented as a comparison between the response of an electret microphone coupled to the preamplifiers and a reference instrumentation-grade microphone and preamplifier assembly. The results show that electret microphones can potentially be used above their rated frequency range of 20kHz; in fact no degradation in signal was noticed up to 48kHz. The results also show that the newly-built SES preamps have a much better high-frequency perfomance than the original ISVR preamps.