sounds like your speakers are consuming a large amount of DC current and this might have caused the damage. High ac voltage on a speaker is better than a low dc voltage.Thiels need a more powerful amp then a Hafler 200. You were most likely clipping this amp.
Hafler DH-200 Toasting speakers
I have a Hafler DH-200 with a Hafler 110 preamp with theil CS-2. I have been enjoying music for a few months now then all of a sudden the mid fried on one speaker and the mid and woofer on the other. I have driven them hard before but not when the problem reared its head. I first noticed the one mid was scratchy so I stopped using the stereo and invited a friend over to take a look at them. When he arrived a few days later I played some music and the mid was completely blown and within a few minutes of low level listening the other mid and woofer were gone. I assume it is my amp doing this but does anyone have any suggestions on fixing the problem? I also have another DH-200 but I am a bit afraid to try it as I have never hooked it up to a system at all. Thanks for any suggestions.