I was running way more power/current to my Pendragons and played them INCREDIBLY LOUD and never had any issues with the tweeters. When I had the Pendragons, I DROVE THE CRAP out of them with a 30-watt tube amp up to a 375-watt Hafler SS amp and never had any issues. And I played them STUPID loud. You maybe got a bad pair? I have the Lore Impluse now in a smaller room - same drivers, just less of them and they are RIDICULOUS for the money... most "fun" speaker I have owned in 20+ years.
Also, your speakers are way too close together and too close to the wall.
