x2 When the sub quits working, push in lightly on the dust cap and see if it comes back on. . . you can also pull the sub out of the box and inspect the wires connecting the sub and see if the tinsel leads look normal. When my JL quit, i checked everything. All visible connections looked fine. I assume that my leads where broken below the spider. If this were true, and i measured the impedance of the voice coils, would that have shown me what was up by the measurements being wrong/off? And since it's a dual voice coil sub, wouldn't one lead of each voice coil have to break before it stops putting out any sound altogether?