As we moved to less beautifully produced content, the center channel sometimes tended to pinch the very tips of consonances, especially «S» sounds which can get a little serpentine, but never stray to all -
out sibilance.
The crisp edge that is needed in order to balance
out the bass response isn't quite there, though there's some tweaking in the high - mids that adds some extra, unwanted
sibilance in spots.