tweak = T = TWENEX
[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.