JohnnyRotten

Hello all, I have had a pair of Heresy 1's for almost 20 years and lately one of them has started to fail: it will not emit any sound until i turn the volume WAY up, then it will give a loud POP and start working properly - even at low volumes. It will then keep working until i shut off the system or if there is a prolonged period of silence out of that channel (in a movie for example). Any suggestions as to where to start looking? I'm guessing the cross-over, but am not sure how to test it??? Thanks, John