I see where my home receiver has a set up for tweeters, mids, and bass. Where can I buy sperate enclosed tweeters for a home stereo on line?

You can buy them, but probably don't want to. Placement of the tweeter relative to the mid is a very important part of speaker design. You can't simply put a tweeter box on top of your current speakers and expect to get decent sound quality, especially off axis. If you tell us what you have already, and what you want to acheive, we should be able to give you better advice on what you want to do.

@ darin: See your other thread regarding your amplifier's capabilities. I'm almost certain that it doesn't do what you think it does.

Cheers, Slipstreem.