Wiring several speakers to one amplifier channel changes the total impedance the amp sees. Go too low and the amp overheats or shuts down. Enter your speakers and wiring below to get the total load in ohms and an instant safety check against your amp's minimum.
How to calculate speaker impedance
Series adds the impedances: two 8Ω speakers become 16Ω. Parallel with identical speakers divides one value by the count: two 8Ω speakers become 4Ω, four become 2Ω. Series-parallel balances the two so you can run more speakers safely: four 8Ω speakers wired as two series pairs in parallel stay at 8Ω. Whatever the wiring, keep the total at or above your amplifier's minimum rated load.
Common wiring results (8Ω speakers)
| Speakers | Wiring | Total load |
|---|---|---|
| 2 | Parallel | 4 Ω |
| 2 | Series | 16 Ω |
| 4 | Parallel | 2 Ω (needs a 2Ω amp) |
| 4 | Series-parallel | 8 Ω |
| 8 | Series-parallel | 4 Ω |
Frequently asked questions
How do I calculate total speaker impedance?
In series, add the impedances (Zt = Z1 + Z2 + ...). In parallel with identical speakers, divide one speaker's impedance by the count (Zt = Zs / n). Series-parallel combines both: pairs in series, then paralleled.
What is the minimum impedance my amplifier can handle?
Most amps are rated to a minimum load, commonly 4Ω and sometimes 2Ω. A lower total than the rating draws too much current and causes overheating, protection shutdown, or damage. Keep the total at or above the rated minimum.
Does wiring speakers in parallel lower impedance?
Yes. Each parallel speaker lowers total impedance and raises current draw. Two 8Ω speakers in parallel are 4Ω; four are 2Ω. Series wiring raises impedance instead.
When should I use series-parallel wiring?
Use it to keep the load in a safe range with several speakers on one channel. Four 8Ω speakers as two series pairs in parallel give 8Ω instead of the 2Ω a straight parallel would give.
Is this the same as a 70V or 100V system?
No. This is for low-impedance (8Ω) wiring. Constant-voltage 70V and 100V systems use transformers and are planned by total wattage tap, not combined impedance.
Distributing audio across a building? Key Digital audio solutions and matrix switchers route and de-embed audio for multi-zone systems. Find a dealer to spec your project.