Free workshop tool
Speaker Impedance Calculator
Calculate the total load for one, two or four loudspeakers wired in series, parallel or common series-parallel cabinet arrangements.
Match the amplifier correctly. Using a speaker load outside the amplifier manufacturer’s permitted output impedance can damage some amplifiers, especially valve amplifiers. Check the amplifier’s output selector, manual and cabinet wiring before use.
Speaker wiring guide
Series vs parallel
Two speakers in series
The impedances add together. Two 8 Ω speakers in series produce a 16 Ω nominal load.
Two speakers in parallel
For two equal speakers, the total impedance is half one speaker’s impedance. Two 16 Ω speakers in parallel produce 8 Ω.
Four-speaker cabinets
Four equal speakers are commonly wired as two series pairs in parallel, or two parallel pairs in series. With four equal speakers both arrangements return the same nominal impedance as one speaker.
Got a speaker or amplifier fault?
Electronic Repairs UK carries out amplifier, powered-speaker and PA repairs from our Telford workshop.
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Read: Speaker Impedance Explained
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