Since they are what they are, an enclosed tweeter, try them without going to all the effort and expense of building an enclosure for them. See if you even like them at all regardless of the brand and value(s) of capacitor(s) you use or select on before you build an enclosure. I found that Solen fast caps are great for high speed sound reproduction like full range speakers tend to be. If you want to tame down the metallic / chalk - like sound inherent to many aluminum ribbon tweeters, try a copper foil in oil cap. from Jensen perhaps to warm up the mids and top end. Your choices and preferences are what matter of course. Parts Express.com would be a great guide for you. 800-338-0531 ph. press 2 for tech. support. Tom