what could have happened?

hello. all of a sudden my mids are thinner and highs are more brittle, with a touch of negative sibilance and an odd crack when a hard "a" is pronounced. i may be being hyper sensitive but when you play with fire(audio)...anyway, all connections seem good.
system:
totem mites
paul speltz anti-cable(solid copper)
onix UFW-10 sub
onix A-60 int. amp
red cobra w/ eichman IC's
toshiba SD-2109 dvd/cdp
audioquest copperhead IC's
digital cable box
any ideas of what might have happened? thanks all.