I have an SG electret microphone (see figure below) connected to my phone, and it produces pretty bad signals (keeps mostly the low frequencies while killing the high frequencies). I suspect it is the microphone (although it might be something else in the circuit). The microphone has a static resistance (without any voltage applied) not lower than 1.5KOhm (I can't measure it exactly since I can't take it out of the circuit, and there are additional things connected in parallel to it). I can't find datasheet on it, so maybe someone had a deal with them before. When I apply voltage to it (1 Volt), the current through it is 0.2mA.

The question is: are these parameters OK for this microphone? Or it is damaged?

SG electret microphone

  • \$\begingroup\$ Electret mics usually have JFETs in them, that may want more than 1v supply. \$\endgroup\$ – ilkhd May 25 '15 at 2:26

Most of the ECMs I've used/seen operate between 1V - 10V.

Also, the frequency response of these guys vary quite a bit. Some ECMs and/or MEMS mics are optimized for a particular bandwidth. For many telephony applications (300Hz - ~3kHz) you'll find a high frequency rolloff, which may be what you're seeing. May want to try out a couple other mics.


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