On Sun, 07 Oct 2007 15:32:09 -0700, ChairmanOfTheBored
wrote:

On Sun, 07 Oct 2007 12:14:12 -0700, John Larkin
wrote:

On Sun, 07 Oct 2007 10:52:54 -0700, ChairmanOfTheBored
wrote:

On Sun, 07 Oct 2007 14:40:56 +0100, Eeyore
wrote:



ChairmanOfTheBored wrote:

Eeyore wrote:
ChairmanOfTheBored wrote:
Eeyore wrote:
PhattyMo wrote:

They have MICRO-farads at best.

I'd guess it's more like pico-farads.

I think it's usually specified in nanofarads actually. It's still farads though,
not ohms.

Graham

It is IMPEDANCE, dumb ****.

Guess what the signifier is. OHMS!

Piezo tweeters are not rated in OHMS.


No, but they present OHMS of impedance to an AC signal source, dip****.

Mainly REACTIVE ones not RESISTIVE.


Still Ohms, nonetheless, chump.

Some speaker cables can have significant amounts of inductance, 10KHz
and up maybe. But the inductance is reactive, namely has a 90 degree
phase shift of voltage drop compared to resistance, so had much less
effect on speaker output.

With an 8 ohm resistive speaker load, 4 ohms of cable resistance drops
volume by almost 4 dB. 4 ohms of reactance only loses about 1 dB.


Nice, Johnny. Except that this sub-thread is about piezoelectric
tweeters.

Any speaker load should be mainly resistive; its function is to make
noise, after all. But if a piezo load has a significant capacitive
component, cable resistance will produce less loss than it would if
the load were purely resistive. And cable inductance could well
produce voltage *gain* into the speaker.

John