"Denny B" wrote in message


Is it possible to measure Impedance with an ohm meter.

Only at DC.

For example can you measure the Impedance of a 4 ohm
car speaker with an ohm meter?

Ironically, most speakers have a nominal impedance that is about the same or
a tad more than their DC resistance. A 4 ohm car speaker will have a DC
resistance that is close enough to 4 ohms to convince most people.

When I tell people they cannot measure Impedance with an
ohm meter, you need an impedance meter and the impedance
must be measured with the speaker in operation, with a signal
generator supplying a fixed frequency, this always leads to
disagreements with the person who demands an ohm meter to measure
what he calls Impedance, when I tell him an ohm meter can only
measure the resistance of the coil there is always disagreement.

You're right. They are wrong, at least in theory.

I tell them Impedance is AC resistance and what they measure
with an ohm meter is DC resistance. Disagreement here again.

You're right. They are wrong, at least in theory.

Will somebody take me up on this and clarify the situation.

The ironic part is that the DC resistance of most speakers is close to the
nominal impedance.