What does speaker impedance mean?
Impedance describes the electrical opposition a speaker presents to the amplifier when playing sound.
Impedance is measured in ohms (Ω).
Common nominal impedances for home speakers are 4, 6 and 8 ohms.
What is the difference between 4 and 8 ohms?
A lower-impedance speaker may require more current from the amplifier at the same output voltage.
This means a 4-ohm speaker often places greater demands on the amplifier’s current capability than an 8-ohm speaker.
However, it does not mean that a lower-impedance speaker automatically plays louder or sounds better.
Can I use 4-ohm speakers with my amplifier?
It depends on the amplifier.
Some amplifiers are designed to drive speakers with a 4-ohm impedance, while others are recommended for higher impedances.
Always check the amplifier’s specifications.
What happens if the impedance is too low?
If the amplifier is loaded with a lower impedance than it is designed for, it may overheat, enter protection mode or, in the worst case, be damaged.
Is the impedance always exactly 4 or 8 ohms?
No.
A speaker’s impedance varies with frequency.
The value in the specifications is normally a nominal impedance used to describe the speaker’s approximate electrical load.
Important: Always check that the speaker’s impedance is compatible with the amplifier, especially if you plan to connect multiple speakers.