Loudspeaker Impedance Example

There are three loudspeakers in a meeting room. Each loudspeaker uses 8 ohms. Calculate the impedance of this circuit.

Step one:

In this example, all of the loudspeakers are the same impedance. Divide the number of ohms by the quantity of loudspeakers.

Step two:

Calculate.

8 / 3 = 2.7 ohms

Message Box 4 Icon
Parallel Circuit Impedance Formula: Loudspeakers with the Same Impedance

The formula to find the circuit impedance for loudspeakers wired in parallel with the same impedance is:

ZT = Z / N

Where:

  • ZT = the total impedance of the loudspeaker system.
  • Z = the impedance of each loudspeaker.
  • N = the quantity of loudspeakers in the circuit.
Message Box 4 Icon
Parallel Circuit Impedance Formula: Loudspeakers with Differing Impedance

The formula to find the circuit impedance for loudspeakers wired in parallel with differing impedance is:

Where:

  • Zx = the impedance of each individual loudspeaker
  • ZT = the total impedance of the loudspeaker circuit

Loudspeaker Impedance Example

There are two loudspeakers wired in parallel. One loudspeaker is 4 ohms and the other loudspeaker is 8 ohms. Calculate the impedance of this circuit.

Step one:

In this example, each loudspeaker has a different impedance. Calculate the reciprocal of each loudspeaker's impedance.

1 / 8 = 0.125

1 / 4 = 0.25

Step two:

Add the two values together.

0.125 + 0.25 = 0.375

Step three:

Calculate the reciprocal from step 2.

1 / 0.375 = 2.7 ohms