Your kid borrows the car, blasts too many techno tracks, and blows out the subwoofer. It used to be that you´d have two choices: Buy a new one (woofer, not kid) or put up with a hoarse bass line. But when a subwoofer pops, it´s usually only the voice coil-the part that drives the cone-that´s burned out; the rest of the assembly is just fine. Boston Acoustics´s SPG555 subwoofer is the first with a replaceable voice coil that you can install yourself.