Try this with good headphones on. Play a high G on the D string with a pick. Pretend you are DeeDee Ramone - all 8th notes all down strokes. All tone controls flat. Now hit the Bright button. That's a +10dB boost right at 10 kHz. +10 dB = twice as loud, so your top end should now be a very annoying twice as loud Clank, Gank, and Wank. If you can't tell the difference, you got serious problems.
I'll try it now.