If your woofers are wired incorrectly, the wire is cheap or below the recommended gauge, or one of your wires is not making full contact to the terminal a few things could happen. A few signs of bad woofer wiring are less bass output, distortion or clipping, a burning smell which indicates burnt voice coils and potentially a blown subwoofer. Occasionally, your amplifier could overheat or catch fire if it does not have safety features programmed into it.