--===============0817374953==
Content-Type: text/plain; charset="big5"
Content-Transfer-Encoding: quoted-printable
X-MIME-Autoconverted: from 8bit to quoted-printable by pch.mit.edu id k6L1m2Ef017584

Mike Singer wrote:

> The greater sound pressure at some moment =A1V the bigger capacitance o=
f
> condenser of a mic and lower its potential at that moment.
>=20
> The greater air speed at some moment =A1V the greater speed of a membra=
ne
> of dynamic mic - the bigger its EMF.

That would mean that if we keep the pressure amplitude constant, the
dynamic mic's output would increase relative to the condenser mic with
increasing frequency: the speed increases (with constant pressure
amplitude).

> Human ear acts more like dynamic mic than condenser one, so when
> listening to sound amplified from a condenser microphones without
> frequency correction, you'll hear it more "high frequency". (The
> higher frequency =A1V the lower speed of vibration at the same pressure=
,
> if I am not mistaken)

I think you're mistaken here. Imagine a simple sine wave with constant
amplitude. When increasing the frequency, the inclination at the zero cro=
ss
becomes "steeper" =3D higher speed of change, faster air movement.

I've tried to find a datasheet of a pure condenser mic capsule, but
couldn't. I think it's a bit more complex than that. You have to take the
built-in capacitor/inductor and both the acoustic and electric coupling
into account.=20

Gerhard


--===============0817374953==
Content-Type: text/plain; charset="us-ascii"
MIME-Version: 1.0
Content-Disposition: inline
Content-Transfer-Encoding: 7bit

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist

--===============0817374953==--