Impedance is the resistance to AC, which is what audio is. You can't measure a speaker's impedance with a DC (battery powered) ohmmeter, doing so will give you an erroneously low indication which would concern anyone. Impedance depends on the speaker's DC resistance,inductive reactance, and its capacitive reactance.
Z is the term for impedance in the below formula. R is the DC resistance measured by an ohmmeter, XL is inductive reactance, Xc is capacitive reactance... all are parts of impedance.
Z is the term for impedance in the below formula. R is the DC resistance measured by an ohmmeter, XL is inductive reactance, Xc is capacitive reactance... all are parts of impedance.