I owned the 3.6's for a few years and had to replace probably 5 tweeters and 3 or 4 midranges. I was using a krell ksa 250 amp at the time. I don't think this speaker is meant to produce very loud music as my wallet will tell you as I never learned my lesson with regards to volume. I had one incident like your friend when both tweeters / mid's failed. I had always sent the failed drivers in when I got replacements but never received any feedback as to the root cause of failure. In the case of the four drivers going out I actually had damaged / failed crossover.Luckily I live about 70 miles north of their factory so I drove the speakers down to them to repair. To Thiel's credit they fixed all that was apparently wrong and after doing a frequency response test discovered a problem with the other speakers crossover which they pulled and fixed. They also gave me a very thorough plant tour and was treated to their custom build listening room which housed about every statement component from all the " major manufactures ".
Blown Thiel 3.6 tweeters/midrange
I'm hoping some you Thiel owners can help me out on this one. A friend of mine blew the mid-range and tweeter on BOTH his 3.6's over the weekend. He went to the kitchen to fix a drink and when he came back there was no music, just a muffled thump from both speakers. Apparently the voice coils have actually pierced the diaphragm and you can hear faint music only if you put your ear close to the drivers. FYI the 3.6s were being driven by an Aragon 8008 ST / 28K fed by a Pioneer PD 65. Any feedback on what could have possibly caused this would be MUCH appreciated!