[Mat Nieuwenhoven]

On Fri, 26 Apr 2019 18:52:00 -0700 (PDT), wrote:

Don Pearce wrote:


Nope. Didn't understand a word of that.



** Really ??

So " I squared R " has no meaning in your world ?

The resistive losses that increase a speaker's mid band, resistive impedance beyond the DC ohms value are also mysterious to you ?

A multiplying power meter, using analogue multiplier ICs, is also a mystery ?

Where have you been hiding Don.

Under a rock?



.... Phil

I squared R has plenty of meaning. Unfortunately a speaker is not an
R. It's an X. And I squared X gives you VA, not Watts. Your
measurement method, applied to a pure capacitor, would apparently
yield a power level. You can't put any power into a capacitor.

d


Oops - let me correct that. A speaker is a whole slew of different R +
jX, with the values being different at every frequency over the
measurement band. No scalar instrument can tell you about power
transfer into that. You can do it with a vector instrument at a single
frequency - and I regularly do that.


But a noise signal with a scalar voltmeter and a scalar ammeter? Nope.
Not on this earth.



** You are making a very basic mistake.

Consider the following:

If you apply a noise voltage to a resistor and measure the current flow with a wide band, true rms meter the formula "I squared R " applies exactly.

If you add an ideal reactance in series with the resistor the formula "I squared R " still applies since the resistor is the only power dissipating item.

A speaker can be accurately modelled as several resistances in series with a lossless reactive component, also in series. snip

Can it? I thought the "Wright emperical model" is the standard model
since 1990.
For interested readers, see
http://www.wavecor.com/Transducer_eq...nt_circuit.pdf for a 1 page
overview
or
https://www.researchgate.net/publica...pirical_Model_
for_Loudspeaker_Motor_Impedance

Wavecor specifically states that the traditional model does not do a
good job at non-low frequencies.

Mat Nieuwenhoven

[[email protected]]

Mat Nieuwenhoven Google Monkey wrote:


wrote:


** You are making a very basic mistake.

Consider the following:

If you apply a noise voltage to a resistor and measure the current
flow with a wide band, true rms meter the formula "I squared R "
applies exactly.

If you add an ideal reactance in series with the resistor the
formula "I squared R " still applies since the resistor is the only power
dissipating item.

A speaker can be accurately modelled as several resistances in series
with a lossless reactive component, also in series. snip


Can it?


** Yep.


thought the "Wright emperical model" is the standard model
since 1990.
For interested readers, see
http://www.wavecor.com/Transducer_eq...nt_circuit.pdf for a 1 page
overview
or
https://www.researchgate.net/publica...pirical_Model_
for_Loudspeaker_Motor_Impedance

Wavecor specifically states that the traditional model does not do a
good job at non-low frequencies.

Mat Nieuwenhoven


** Any damn fool can use Google and find something that appears to differ from any statement of fact you care to mention.

This is no contradiction between the information in my post and what the above Google Monkey has found.

And in any case, he has not to the tiniest ****ing clue.


...... Phil