When measuring the voice coil of a speaker with a DMM set to ohms while at rest, what is being measured?

When measuring the voice coil of a speaker with a digital multimeter (DMM) set to ohms while at rest, you are measuring the DC resistance of the voice coil. This measurement is taken while the speaker is not in operation, meaning that there is no alternating current (AC) flow through the voice coil, which allows for a purely resistive measurement.

DC resistance provides insight into the condition of the voice coil and helps in determining whether the coil is functioning correctly. It reflects the wire's resistance in the voice coil and can indicate potential issues like shorts or opens if the resistance falls outside of expected values.

Impedance, which is a combination of resistance and reactance, would be relevant when the speaker is in operation and subjected to an AC signal, as it varies with frequency. Voltage drop pertains to the reduction in voltage as current moves through a circuit but is not applicable in the context of measuring static resistance in a voice coil.