4 ohm vs 8 ohm speakers: What’s the difference?

*As an Amazon Associate, we earn from qualifying purchases

If you’re thinking about setting up your own center channel speaker system in your home, then it can be a little confusing. There are many different things for you to get your head around, including the words and terminologies that are used with speakers. One of the most commonly misunderstood things about speakers are ohms; what are they, what do they do and what’s the difference between 4 ohm and 8 ohm speakers?

And whilst is probably isn’t the easiest thing to understand, once you do you’ll know exactly which you need to get for your own speaker set up. So, let’s check out the difference between ohms and impedance in relation to your speakers.

4 ohm vs 8 ohm speakers

The difference between 4 ohm and 8 ohm speakers is just a simple difference in speaker impedance, which is the electrical current resistance and its capacity for electrical current combined.

You’ll need a more powerful amplifier to deal with 4 ohm speakers, as many standard amplifiers are designed to be used with 6 or 8 ohm speakers, so they don’t have the power required to be compatible. Ideally, you’ll have matching speaker and amplifier impedances to get the best sound quality from your wire speakers.

It can also depend on whether you’ve got one speaker or two speakers in your setup. So before we get into that, let’s look at what exactly ohms are in the first place and how electrical current works.

What are ohms?

The first thing to understand if you’re trying to work out the difference between 4 ohm speakers and 8 ohm speakers is what exactly ohms mean in the first place. Essentially, it’s a way that we measure some of the basic units that are used in electricity.

So, we know that voltage is measure in volts, and the electrical current in measured in amps. Then we come to resistance, which is quite simply the opposition, or resisting, of the electrical current that’s running through a circuit. And how do we measure electrical resistance? That’s right; in ohms.

This means that we can work out the current of an electrical circuit by simply dividing it’s voltage by it’s resistance. However, this doesn’t give us the ohms measurement that we use in speakers on it’s own. Whilst it does make up part of the equation, with speakers we used an impedance rating, not just a resistance rating.

Impedance Rating

So, resistance is just the force agains the current in an electrical circuit, and it’s measure in ohms. It makes sense that this is what we use to measure impedance in speakers, but this isn’t actually the case. Impedance in speakers is the resistance of the current, but it also takes into account the reactance of a circuit as well.

The reactance of the speaker is made up of different factors. This includes the capacitance of the circuit, which as it sounds, is the circuits ability to store electrical charge. It also takes into account the inductance of the electrical circuit too, which is it’s tendency to oppose the electrical flow.

These are the main differences between resistance and impedance. Another thing to mention about impedance is that it can only happen in an AC circuit. With resistance, this can take place in a DC circuit as well as an AC circuit. We measure the resistance of a circuit with the unit R, whereas the impedance is measured with the symbol Z.

So, what’s the difference between 4 ohm and 8 ohm?

Whilst this explain how ohms work in speakers, this doesn’t really say the difference between 4 ohms and ohm speakers themselves. The truth is thatv Ohms aren’t a fixed measurement. This means that a 4 ohm speaker can dip to 3 ohms and rise to 5 ohms, and the same is correct for an 8 ohm speaker as well. But, this does tell us the overall capabilities of the speaker.

The main thing this means for us is that we need to get the right amplifier for the speakers, or we could have serious problems. As you can see, a 4 ohm speaker has less resistance and is therefore going to need a lot more power than a 8 ohm speaker. But many amplifiers are only capable of working well with 8 ohm speakers, and if you use them with 4 ohm speakers, then you’ll encounter problems, as they’re a power mismatch.

So, this just means that you need to match up your speakers and your amplifier accordingly. If you do this, then everything should work as planned. Many people think that the ohms a speaker has will be directly related to it’s loudness, and this isn’t really true. A 4 ohm speaker can’t necessarily play a lot louder than an 8 ohm speaker.

However, if you using an amplifier with an 8 ohm speaker, and sending one watt of energy to it, then this would double with a 4 ohm speaker, and you’d be sending 2 watts as it needs double the energy. So, it would be a little louder in terms of volume.


In conclusion, it’s clear to see the difference between 4 ohm and 8 ohm speakers. A 4 ohm speaker is going to need to be supplied with more power from your amplifier, with a lower impedance rating meaning that you need a stronger current to counteract this. Otherwise, you can end up getting poor sound quality and a higher power consumption than what’s necessary.

Whilst there are no real benefits of opting for 4 ohm over 8 ohm, many of the top speakers are designed to work with 4 ohm amps – this is just the way that the manufacturer has managed to find the best sound for their speakers.

Leave a Comment