My JBL EON G2 10s have served me well as a small PA or as monitor speakers, until they suddenly developed a nasty rattle. At first I thought I’d blown a woofer, but a quick inspection behind the grill showed everything was in order. Then I noticed that something inside each speaker was loose–it would make a disturbing clunk sound whenever I moved it. So I pulled the back off (so many screws…) and discovered the toroidal transformer was loose. I applied a dab of Loc-tite, tightened the bolt, and reassembled the speakers. Now they’re rattle free!