Sub Box Calculator › Subwoofer wiring calculator
Subwoofer wiring calculator
Pick your sub from the database or enter it by hand — how many, single or dual voice coils, coil impedance and RMS power — then your amp’s RMS power at 4, 2 and 1 Ω. You get every way to wire them, the final impedance, the watts each sub gets and step-by-step connections.
Series, parallel and dual voice coils
- Series adds impedances: two 4 Ω coils in series are 8 Ω.
- Parallel divides them: two 4 Ω coils in parallel are 2 Ω (for equal impedances, divide by the number of coils).
- A dual voice coil (DVC) sub has two coils on one cone. Always use both, wired in series or in parallel, so one sub gives two impedance choices: a DVC 4 Ω sub is 8 Ω or 2 Ω.
- With four subs there is also series-parallel: two pairs in series, the pairs in parallel. The final load equals one sub’s impedance.
Which impedance to choose
An amplifier delivers more power into a lower impedance, but each amp has a minimum it is stable at — usually 1 Ω or 2 Ω for mono amps, 2 Ω per channel or 4 Ω bridged for multichannel amps. The lowest load with a power figure in the spec sheet is that minimum. Going lower overheats the amp and makes it shut down.
Enter the RMS power, not the peak or “Max” figure, which is usually 2–4 times higher. The calculator splits the amp’s power between the subs and compares it with each sub’s RMS rating: 75–110 % is good, much more risks burning the voice coils, less leaves the subs underpowered. The option marked Best for your amp gives the most power within that range.
Wiring does not change the sound of the sub itself: the frequency response and cone excursion at the same power stay the same. It only changes how much power the amp can deliver. To see how loud and how deep your subs will play in a box, model them in the full calculator.
Design the box for your subs→FAQ
How do I wire two dual 4 ohm subs?
Wire the coils of each sub in parallel (2 Ω per sub) and the two subs in parallel for a 1 Ω load, if the amp is 1 Ω stable. Otherwise wire the coils in series (8 Ω per sub) and the subs in parallel for 4 Ω.
How do I wire a dual 2 ohm sub?
Coils in series give 4 Ω, coils in parallel give 1 Ω. Use 1 Ω only with an amp that is 1 Ω stable.
Does series or parallel wiring sound better?
Neither: the sub sounds the same at the same power. The wiring only changes the load the amplifier sees, and so how much power it can deliver.