I have recently inherited 4 pair of vintage JBL speakers...L65s, L100s, L200s and L220Bs. In listening to the L65 and L220s last night it became apparent that one of the L65s output was not the same as the other. Then I noticed that the woofers were different. I need a primer on all of these speakers as to what is the best and most cost effective way to replace or renovate woofers, and mid-range components. I enjoyed what I heard and think these can be some very nice additions to my stereo systems if I can make sure I do the right things now