Many people are constantly torn between 4 Ohm and 8 Ohm speakers, and they are left wondering about speaker impedances, what they mean, and what they represent.
Surprisingly, higher impedances do not necessarily indicate better speakers, nor do they translate to more powerful equipment.
The impedance of a speaker relates to how easy it is to drive power to that equipment. How exactly this works and why it matters is what this article is all about
We will cover all the related terminology, how impedance works in real-time, and everything you should know to get back to what matters, your music and movies.
Affiliate Disclosure: AmplifierZone is reader-supported. As an Amazon Associate, we may earn commissions from qualifying purchases at no extra cost to you.
What Is Speaker Impedance?
Speaker impedance is a measure of the resistance to an electric current, i.e. the music signal. Using the electrical resistance jargon is the combination of the resistance and reactance of the circuit.
Unlike basic resistance, which only resists current, reactance does so without dissipating power. Impedance is simply the total opposition the speaker circuit presents through a combination of reactance and resistance. It varies depending on the frequency and takes place in an AC circuit.
A speaker rated at 8 Ohms will vary according to the frequency of the signal, sometimes even going as high as 40 Ohms or as low as 4 Ohms, depending on the frequency.
The impedance rating is mostly a notation of the speaker’s lower impedances on average. It’s still a good indicator of how much power output you require to drive the speaker.
The higher the speaker impedance, the easier it is to power the speaker. This means that you will need a less powerful amplifier to drive electrical signals to the speaker. On the other hand, the lower the impedance, the more power you require froma quality amplifier.
Because lower impedances will allow more electric signals to pass through, they will consume more power compared to higher impedances that allow fewer electrical signals.
Falling outside the rated speaker ranges will lead to impedance mismatch, which can cause distortion, and clipping, and can eventually damage the speaker.
Now that you understand exactly what impedance refers to and its direct implications on power ratings, the next thing you are probably wondering is how does impedance affect the quality of the speaker?
4 Ohm vs 8 Ohm: Loudness
Speaker impedance is not a direct indicator of loudness.
In other words, a 4 Ohm speaker will not necessarily play louder than an 8 Ohm speaker, or vice versa. This just means that if you are using a capable amplifier to drive 1 Watt of energy from each speaker, you will need different energy levels.
For each Watt of energy sent to the 8-ohm speaker, you will send 2 Watts to the 4-ohm speaker to produce the same output. This