Jim Lesurf wrote:

So far as I can recall, it isn't 'news' that caps can have mechanical
resonances. The claim that is interesting is that they are audible. But to
decide, I'd need to know a lot more about how the 'results' were obtained.
For reasons like those others have already mentioned.

Crappy quality ones (electrolytics at least) can be bad. I've come across some.
Doesn't mean you have to use magic dust or incantations to fix it though, just
buy well-made quality product.

Graham