Testing electrolytic cap ESR with REW?

[erileykc]

I've got a pair of speakers with some 25 year old electrolytic caps but no ESR meter. Is there a test configuration that would allow REW to give useful results on these caps?

 

[John Mulcahy]

You can do an impedance measurement then fit a component model to get an equivalent circuit. The graph will directly read dissipation factor values at the cursor frequency.