Mike Rivers wrote:
However, the copper voice coil IS a simple resistance hence
I squared R applies. You did not read my post.
I probably read your post but I don't remember it.
** My post was to Don Pearce - not you.
If you're talking about a DC measurement, you're correct - resistance is
all that's there. But if you're making an AC measurement - and why
wouldn't you since a loudspeaker isn't very useful when fed by DC? -
it's also an inductor, a capacitor, and, unless you remove the magnet so
the voice coil doesn't move, it's a generator, too.
** As far as heat dissipated in the copper voice coil is concerned, I squared R gives the answer. R varies with temperature, but nothing else.
** Not at all, an ideal capacitor has a resistance of zero.
Only when you first apply a steady voltage to it. Once it's fully
charged (which may take close to an infinite amount of time, but you can
get pretty close pretty quickly), it has near infinite resistance.
** Oh dear - an ideal capacitor has ZERO series resistance.
This was clear from the context, which it seems you did not read.
But when you feed AC to a voice coil, you absolutely can't ignore everything
but resistance when measuring power.
** Which I did not - try reading ALL of what I wrote.
Over sniping and shifting contexts like you just have is very bad usenet practice. One might be forgiven for thinking you a troll.
..... Phil