jetter - never was able to get a definitive answer as to what caused the tweeters to go. That said, I did have them replaced by the dealer, although at significant expense for both the tweeters and labor. Although I understand that the two tweeters going at the same time indicate it was probably not a " product defect" issue, I'm a bit disappointed that neither the dealer nor Proac offered to share in any of the repair cost (speakers are only 2.5 years old with very moderate use). I always thought buying from a local brick and mortar dealer was a wise thing to do - for issues just like this. But with the level of support I experienced, now I'm not so sure. And I'm a bit reluctant to continue to use my amp - looking into getting a replacement. Gotta save up the $$$$!