While series wiring of multiple subs increases the total effective impedance, parallel wiring of multiple loads lowers the total effective impedance. With subwoofers rated at equal impedances, the system impedance is equal to the impedance of one sub voice coil divided by the number of subs.

What is the best way to wire subs?

5:1410:10How To Wire Subwoofers - Parallel vs Series - Single Voice Coil and Dual YouTubeStart of suggested clipEnd of suggested clipSingle voice coil subwoofers are a lot easier to wire mainly because they have only one set ofMoreSingle voice coil subwoofers are a lot easier to wire mainly because they have only one set of terminals. For parallel all you do is connect the positive of the sub or subs to the positive of the amp.

What is the disadvantage of parallel?

A disadvantage of parallel circuits is that they require more wiring. Additionally, the voltage cant be increased in a parallel circuit without decreasing the resistance in the circuit.

What is dual 4ohm?

In a parallel hook-up, the drivers impedance will be half that of each individual coil (a dual 4 ohm speaker would be a 2 ohm speaker in parallel). A series hook-up results in twice the impedance of each single coil (a dual 4 ohm speaker results in 8 ohms if its coils are wired in series).