Actually, I did try. They have a cap there probably to block the lower frequencies (an LC circuit?). So, I couldn't easily get a resistance measurement.
I did measure .68uf at two different frequencies with a cap meter. And measured about 8 ohms impedance at 100khz with another meter. That happens to be the frequency the meter uses.
The tweeter is marked 15w. That's not a lot of power, but a lot for a tweeter.
Maybe next time I am in there, I'll try more testing ...