Just a quick mention from me, I did measure my Sprauge cap with both a low cost ESR meter and my Fluke, while I actually do think the ESR meter can measure esr okay (based only upon comparing various resistor measurements of my ESR meter and my Fluke, they were almost identical), however capacitor readings were off compared to the Fluke and of which I'll trust.
I find it interesting also that you have the rheostat and the woofer with cap/resistor setup, cool keep up the good work.
Ben