Re: diaphragm output & phase: HC selectivity ... and the lateral organ of the fish

[Steve Beet <steve.beet@xxxxxxxx>]

Hi Kevin,

I'll keep this short because it's getting a bit off-topic, but if you look
at B&K's web site (http://www.bksv.com/3095.asp) and search for very low
frequency microphones, you'll find the only ones which go down to DC are
"piezoresistive" designs. The lowest frequency they quote for a condenser is
0.07 Hz. Pretty low, but not DC.

I believe RF condenser microphones can extend down to DC too, but the most
common condenser mikes rely on a high impedance DC bias voltage, with that
(resistive) impedance combining with the capacitance of the microphone
itself to make a low-frequency time constant which prevents a true DC
response.

Steve