In most cases, dual voice coil subwoofers are slightly more expensive than the same model with single voice coil design — but not by very much. Using a dual voice coil subwoofer, you can drive the subwoofer with enough power by using one channel for each voice coil. A single voice coil subwoofer has a metal core attached to the cone and one set of wires connected to it. Thanks for your kind words. All you need to do is connect the first set of positive and negative terminals to one another, then repeat this for the second pair of coils. There are performance differences between dual and single voice coils mainly due to efficiency, magnet strength, power handling, and frequency range. Gracias mil. If one subwoofer has an impedance of four ohms and the other is two ohms, the speaker with a lower impedance should be connected to one channel of your amp.