Match your speakers to your amplifier with confidence. Enter your speaker ratings, pick a wiring style, and see the final impedance with a visual diagram.
Most car audio amplifiers rated for 2-ohm stereo loads can handle this configuration.
Connect the positive terminal of the first speaker to the amplifier. Run a wire from the negative terminal of that speaker to the positive terminal of the next speaker. Continue down the chain. The last speaker's negative terminal goes back to the amplifier.
Total = Z1 + Z2 + Z3 + ...
Two 4-ohm speakers in series give 8 ohms. This is the safest wiring method and works with almost any amplifier.
Connect all speaker positive terminals together and run one wire to the amplifier's positive output. Connect all negative terminals together and run one wire to the amplifier's negative output.
1 / Total = 1/Z1 + 1/Z2 + 1/Z3 + ...
Two 4-ohm speakers in parallel give 2 ohms. Make sure your amplifier is 2-ohm stable before using this setup.
Wire pairs of speakers in series first. Then wire those series pairs together in parallel. This is the go-to method for four or more speakers when you want to keep impedance in a usable range.
Each series pair = Z1 + Z2. Then treat pairs as parallel: 1/Total = 1/Pair1 + 1/Pair2
Four 4-ohm speakers in series-parallel give 4 ohms total. Safe for most home stereo and many car amplifiers.
A dual voice coil sub has two separate coils. You can wire the coils in series or parallel to change the starting impedance before you even calculate the system total.
A dual 4-ohm DVC sub: coils in series = 8 ohms, coils in parallel = 2 ohms. Then wire multiple subs together using series or parallel rules.
Your amplifier is designed to deliver power into a specific impedance range. Too low, and the amp tries to deliver more current than it can handle. This causes overheating, distortion, and eventually permanent damage.
Too high, and you leave power on the table. A 4-ohm speaker on an amp rated for 2-ohms might only give you half the rated wattage.
Getting the impedance right means your system runs cool, sounds clean, and lasts for years.
In series, you wire speakers end to end. The impedances add up. Two 4-ohm speakers in series give 8 ohms. In parallel, you wire all positive terminals together and all negative terminals together. The total impedance drops. Two 4-ohm speakers in parallel give 2 ohms.
Every amplifier is designed to work with a certain range of speaker impedance. If the load is too low, the amp overheats and can shut down or get damaged permanently. If the load is too high, you won't get full power output. Matching impedance keeps your gear safe and sounding right.
You can, but the math gets more complex. In parallel, the lower-impedance speakers draw more current, which can cause uneven volume and stress the amp. This calculator handles mixed values, but it's best practice to use identical speakers in the same wiring group.
A DVC sub has two separate voice coils, each with its own impedance rating. You can wire the coils in series or parallel first, then treat the result as a single speaker. A dual 4-ohm DVC sub wired in parallel gives 2 ohms. Wired in series, it gives 8 ohms.
Series-parallel combines both methods. You create small groups of speakers wired in series, then wire those groups in parallel. This is common when you have four or more speakers and want to keep the total impedance in a safe range.
The calculator uses standard electrical formulas for series and parallel resistance. It assumes the rated impedance printed on each speaker. Real impedance varies with frequency, so the actual load your amplifier sees may differ slightly. For critical builds, measure with a multimeter and consult your amplifier's specifications.
For runs under 10 feet in a car audio setup, 16-gauge speaker wire works for most applications. For longer runs or high-power systems (over 500 watts), step up to 14-gauge or 12-gauge. Thinner wire adds resistance and wastes power as heat.