I thought something was wrong with one of my LMS Ultra drivers because I was hearing something that would normally be characterized as mechanical noise from a sub. I thought, oh great now I'm going to have to replace the basket assembly, which is easy enough to do, but at $490 + shipping, ain't exactly cheap. Lucky for me, it turns out one of the drivers is firing into the somewhat cheap rolling island we have and it's vibrating the sh!t out of one of the flimsy back panels (as well as the floor, everything on top of the sub, the wall, the garbage can, etc, etc). So the bright side is that the driver is fine. The downside is that I have this irritating sound every time a big bass scene comes up. Damn first world problems.<style id="pageBrightnessCustomCSS">body{zoom:175%;}</style>