Speaker Impedance Calculator
Speaker wiring impedance: series, parallel and series-parallel.
About this tool
Choose identical speakers (number, impedance and wiring) or enter a list of mixed impedances. Add your amplifier's minimum load and power to check it's safe and see how much power each speaker gets.
How speaker wiring changes impedance
In series, impedances add: two 8 Ī© speakers give 16 Ī©. In parallel, they combine as 1/Z = 1/Zā + 1/Zā + ā¦, so two 8 Ī© speakers give 4 Ī© and four give 2 Ī©. Series-parallel wiring combines both: four 8 Ī© speakers wired as two series pairs, with the pairs in parallel, give 8 Ī© again, a common way to run more speakers on one channel. Keep the total at or above your amplifier's rated minimum load, usually printed near the speaker terminals (often 4 Ī© or 8 Ī©), or the amp may overheat or shut down. Identical speakers share power equally. Mixed speakers don't: in parallel the lower-impedance speaker draws more power (an 8 Ī© and a 4 Ī© make 2.67 Ī©, and the 4 Ī© takes two-thirds), while in series the higher-impedance one does. Honest limits: nominal impedance is an average and real speakers dip lower at some frequencies; commercial 70 V and 100 V line systems use transformer taps instead. The decibel calculator and the series and parallel resistor calculator are related.
Frequently asked questions
What is the impedance of two 8 ohm speakers in parallel?
4 Ī©. In series, they would be 16 Ī©.
How do I wire four 8 ohm speakers to get 8 ohms?
Wire two pairs in series (16 Ī© each), then connect the two pairs in parallel: 8 Ī© total.
Can I run a 2 ohm load on a 4 ohm amp?
Not safely. It may overheat or shut down; keep the load at or above the amp's minimum.
How is power shared between mixed speakers?
In parallel, lower impedance takes more power; in series, higher impedance takes more.
Is my data sent anywhere?
No. Everything is calculated in your browser, and nothing is stored or sent.