Speaker Impedance

How to use this calculator

Loudspeakers combine like resistors. In series the impedances add: Z = Z₁ + Z₂. In parallel they combine as the product over the sum: Z = (Z₁·Z₂)/(Z₁ + Z₂). Enter the two driver impedances and choose the connection, and the total load on the amplifier appears live.

What it means in a real circuit

An amplifier is rated for a minimum load (often 4 Ω or 8 Ω). Wiring speakers in parallel lowers the total impedance, so two 8 Ω speakers in parallel present only 4 Ω — fine for a 4 Ω-capable amp, dangerous for an 8 Ω-only one. Use this to verify your cabinet wiring stays within the amp's safe range before connecting, and to plan multi-speaker arrays.