Capacitor

Here's a link to a guy that did extensive listening tests for crossover caps. 

http://www.humblehomemadehifi.com/Cap.html

I've found the copper foil in oil caps from companies such as dueland, Jupiter and miflex sound the best, but these can get quite expensive and are quite large.

The only identified issue with film caps is a potential for mechanical resonance specific to a frequency but audiophiles make up all kinds of things like posts in this thread. Caps can be in high or low pass filter networks. They are critical in both.

So which is it then? Because if they are so critical then it would seem we would want the best ones, and you already admitted there are problems like mechanical resonance. Which is indeed a factor. So how can you be sure we are just "making up all kinds of things" about which is best? Help me understand your, uh, reasoning.

This really depends. With a value this high I have to assume it’s a low pass filter. If so it is likely to go to ground.

@erik_squires,

If the cap goes to ground, then it’s shunting all the frequencies above that driver’s cutoff to ground, essentially a short circuit, not a good thing for the amp. Unless the signal through the cap goes to another driver like a midrange or tweeter and then to ground, that’s different. However, a series inductor will block the higher frequencies and send nothing to ground, a "safer" option. We haven’t see an photo or a crossover schematic to tell where the parts are connected.

Rather than replacing the entire cap, you may want to get a really good cap of a smaller value, say 0.1uf or .22uf and bypass the existing 100uf cap. Audyn is not junk, they are reasonably good caps.  

If the cap goes to ground, then it’s shunting all the frequencies above that driver’s cutoff to ground, essentially a short circuit,

Man, I no longer have the time and energy to explain the basics, let alone the subtleties of even ordered crossovers. This crap  is why I barely post here.