Replacing speakers with mystery salvage parts. Impedance?

[ManisMan]

How do you find the impedance of a speaker? Are you just supposed to know, or have some stamp on the speaker body, or is there a method of testing it?

[jjasilli]

Measure its resistance with a DMM.  This fixed resistance will be about 2/3 of its impedance rating.  E.g., an 8 Ohm speaker will have a fixed resistance reading of about 6 Ohms.

[ManisMan]

Thanks