On Sun, Aug 24, 2014 at 07:19:11AM -0700, Len Ovens wrote: > That is true and for most studio mics (anyone use crystal mics?) it > would be minimal. Anytime eq is used to bring back low level > frequencies, it is likely to bring back the noise around that > frequency too. Instrument pickups are most sensitive to this. I have > a classical guitar that I put a piezo into.
Piezos have a capacitive impedance, together with the preamp resistive input impedance this forms a first order highpass filter. A typical mic input is around 2 kOhms, this would place the cutoff frequency somewhere in the high audio range, with 6 dB/oct below that. Could be EQ'd in theory, but for musical use it's usually better to use a high-Z preamp. Some specialised preamps (e.g. for piezo hydrophones), actually do use a 'zero impedance' input, and integrate the signal to compensate. This provides the best FR and the most stable calibration, and allows the use of very long cables.. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow) _______________________________________________ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
