"eponymous cowherd" wrote in message
...

My speakers are 20 years old and until today I thought they were going
strong. I have always known that they sound better with the grills off,
but because the drivers are made with polypropelene I have always
assumed that I should mostly keep them on to protect them from UV. Every
once in a while I take the grills off and today I did so. For whatever
reason I decided to touch the tweeter dome and was surprised that I
could not feel any vibration at all. I turned the treble knob to full
and tried changing CDs but I could never feel the tweeter dome move at
all, this was on both speakers. Am I supposed to feel the tweeter dome
move?

Tweeters don't move very far. If you turned the treble all the way up, you
should hear them shrieking like mad when you stick your ear in front of one.