Speaker Impedance Matching Guide

Impedance Is What the Amplifier Sees

An amplifier does not know how many drivers you connected. It sees one load, in ohms, and delivers power according to that load and its own stability rating. Wiring two drivers the wrong way can halve the load and push an amplifier below what it is rated to drive.

Series and Parallel

Series wiring adds impedance. Parallel wiring divides it. For identical drivers the arithmetic is simple: parallel is the driver impedance divided by the number of drivers, series is the driver impedance multiplied by the number of drivers.

Dual Voice Coil Drivers

A dual voice coil driver gives you two coils to combine, then combines again with any other drivers in the system. A dual 2-ohm driver can present 1 ohm with its coils in parallel or 4 ohm with them in series. That flexibility is the reason DVC drivers exist, and it is worth choosing the coil configuration at purchase rather than trying to rescue a mismatch later.

Nominal is not measured

A 4-ohm driver is nominally 4 ohms. Real impedance swings with frequency and rises sharply at resonance. Amplifier ratings and stability figures are written against the nominal value, so use nominal for the arithmetic and do not be alarmed by a meter reading a DC resistance of around 3.2 ohms on a 4-ohm coil.

Get the Diagram Before the Wire

The subwoofer wiring diagram generator takes the driver count and coil type and returns the wiring that lands on the impedance you want, so the question is settled before anything is cut or crimped.