Help with Martin Logan Quests.

All of the advice above is good. Do vacuum the panels regularly, but honestly--it's time for new panels. M-L has made a number of improvements for their panels, and you will benefit from these as well as the fact that yours are probably near the end of their life expectancy--particularly if you live in a humid area which lowers the life expectancy.

I would call Jim Powers at Martin Logan. Tell him the problems and the results--particularly the last story. While, I can share my experience with my Martin Logans (and a few friends), he hears hundreds of experiences and works to resolve them. He is a great resource and can likely tell you if it's the panels or possibly something else. My guess is that it's the panels and the combination of high humidity--but would be interested in what Jim tells you. He can also tell you what circuit updates were made and if they make sense for you. Your speakers may not have the auto off/on which could be a significant upgrade being in a high humidity area--they increase panel life quite a bit. Mine didn't have this either, but I just created a manual method that I used to accomplish the same thing.