A speaker part that handles the high-frequency sound. They are usually not a standard speaker cone; sometimes they are made of titanium, which is found on high-end speakers. They are usually no more than 1.5" in diameter on home theatre speakers. The midranges and woofers handle the rest of the sound.

tweeter n.

[University of Waterloo] Syn. perf, chad (sense 1). This term (like woofer) has been in use at Waterloo since 1972 but is elsewhere unknown. In audio jargon, the word refers to the treble speaker(s) on a hi-fi.

--The Jargon File version 4.3.1, ed. ESR, this entry manually entered by rootbeer277.