I'll take a chance at being shunned for this, but here's what I did. I bought a pair of L-780's from the infamous unmentionable online auction place. Tweeters and mids were not protected and had paper stick to the domes (what a surprise!). Anyway, nothing to lose right? Lacquer thinner to the rescue. Using a very small paint brush, the kind you would use to paint a model car not a wall, I carefully dabbed it on again and again. It softened the damping material and I was able to get almost all of the crap off the domes. You must be extremely careful not to put too much on at one time. I carefully brushed and smoothed out the coating. Unfortunately, one of the mids was so bad that I ended up taking off about half the coating. It looked bad and I thought I would have to replace it. The tweeters and the other mid came out good, almost look new. Thought about this for a long time trying to figure out what to do. These are back-ups to my main speakers so they just sat for a while. One day, I don't remember what triggered the thought, I remembered that rubber cement had a similar consistancy to the dome coating. I bought some and tried it, blended right in with the original coating. I used a small brush again and carefully applied it. The cement I used was Elmer's rubber cement available at Walmart, Walgreens, etc. The damaged mid looks very good, not perfect. The rubber cement stays pliable and seems to be very similar to the original coating. I would only recommend this for sitiations like mine where it is a last resort attempt at a fix. I saved four expensive drivers for a couple bucks and an hours work.
It worked for me, but If you try this you are on your own. I offer no guarantee it will work for you. Do this at your own risk!!!!!
Jon
