I made the Pi 2 tower about 2 years ago and one of the drivers has blown>>>>>>>>>>>>>>>>>>>>>>>>>>If it makes you feel any better I blew 3 woofer in 6 months on my Klipsch Reference series speaker that I just sold. (good ridence too!)
I blew at least 10 tweeters on my Adire Kit 281s over the course of 3 or 4 years.
Maybe its time you step up to something a little beefier , I am sure your Son would appreciate it as well! :-)