Love my UL410's (both are series 1, 4ohm), but on one of them the top right driver rattles the slightest bit. The rattle is especially pronounced when I play lower notes, like the open B or E string. At loud volumes its unnoticeable and I don't think it's a blown driver or anything, but when playing at bedroom practice volumes, it's definitely audible. Do you guys have any idea what it could be? I took the grill off and took the driver out, and there was nothing loose or anything. I'm thinking it could be an internal component thats loose or broken, but is it something that I could open up and see for myself, or do I need to send it in? Thanks!