Speakers come in single voice coils only, but a subwoofer can come in a single or dual voice coil. A dual voice coil subwoofer won't sound better or perform better, if everything is the same such as windings, magnet, cone materials, etc. The primary reason to pick a dual voice coil subwoofer is configuration options. It will give you the flexibility to match your subwoofer's impedance to the max with your amplifier. And if that is matched better than a single voice coil sub would, then yes, you can have a better sounding subwoofer with a dvc subwoofer!