What does a bad tweeter sound like?

I'm not familiar with those speakers, but if the crossover isn't a real bitch to remove checking those caps out wouldn't be a bad idea. I doubt you have a leakage tester, but all the caps should measure up into the megaohms on a resistance test after a few seconds. Caps also tend to drift out of spec when the go leaky, but not always. Most of the leaky ones I've dealt with had drifted outside tolerance, but not all. They all failed to effectively block a few volts on a ohm meter though. 

I just found the 5A crossover. :) I would leave it alone unless you are already pretty well versed.

The 5A uses batter biased caps int he mid and tweeter sections. Pretty funky if you ask me. :)

Geez Stringeen ......I thought you had '' golden ears '' as you have proclaimed here after working in recording studios and you couldn't tell know if those older Vandersteen's tweeter is gone ? Maybe it is time to use them as door stops ......  

...just got the tweeter back and installed...just as I thought - the tweeters were checked to be working perfectly.   Vandersteen told me to check for tightness around the face plate....if not buzzing, then the only thing left is to check the crossover.   YUK.  This is no fun.

erik_squires....you probably know this, but the crossover and cables have a charge constantly going through them powered by a battery pack that gets changed every couple of years.  The idea is the same as Audioquest cables has. Its actually simple but not really elegant, since the batteries have to be hard wired in the amp, crossover, and high pass filter box.  ...done not often, but when all the batteries come back and installed after being run down a bit, the speakers have an new found clarity and power. It works.....