Whether you want booming bass or a balanced sound, it’s important to understand precisely what kind of speakers are best for assembling that perfect audio system.
As a driver who wants your car audio system to perform optimally, you need to know the difference between 2 ohm and 4 ohm car speakers.
Understanding how each type works will help you decide which is most suitable for your setup, ensuring that you’ll always have great-sounding tunes.
The main difference between 2 ohm and 4 ohm car speakers is their electrical resistance. Because of that 2 ohm speakers play louder sounds than 4 ohm, but their higher power consumption makes the sounds they produce lower quality.
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In the article below, you will find more information about how to choose the right impedance for your car speakers, and how to match them with amplifiers.
As an Amazon Associate, ImproveCarAudio will receive a small commission from qualifying purchases made through the links in this article.
Tip: When searching for your car’s loudest possible sound system, consider 2-ohm speakers.
Although they require more power, you will not be disappointed with their sound. To find the best 2-ohm speakers, check out my favorite picks on Amazon.com.
In the article below, you will find more information about choosing the correct impedance for your car speakers and how to match them with amplifiers.
What Is Impedance in Car Speakers?
Impedance is the resistance of the single voice coil wire against the flowing current from the amplifier. Most car speakers are manufactured in either 2 or 4-ohm impedance.
Although you can find exceptions, like the Kicker CompRT 10″ subwoofer with a 1-ohm impedance, it will be difficult to find car speakers or amplifiers over 4 ohms because of the low 12V voltage.
Kicker CompRT 10″ is an excellent choice when you are looking for strong “kicks” and do not have much room for a deep woofer.
It is available on Amazon, and if you want to try its real power, click this link and check the latest price.
When you see 4 ohms on the speaker, it does not mean its impedance is 4 ohms constant.
In reality, this value constantly changes because it depends directly on the speaker’s current frequency and can be as low as 0,3 ohms or as high as 30 ohms.
The impedance will be higher for the lower frequencies, and for higher frequencies, it will be lower. This is one of the reasons why voice coils in tweeters are so small.
To summarize, the 4-ohm value placed on the speaker is the “nominal impedance,” representing the average of all impedances the speaker has been designed to work with.
Because the speaker’s impedance is related to wattage, the higher the impedance, the lower current will flow from the amplifier. That means an amplifier will be less loaded when working with higher impedance speakers.
For example, a 100W 4-ohm speaker will draw a 100W from the 4-ohm amp, while a 2-ohm speaker will force the same amp to produce 200W.
As a result, the amplifier can be overloaded, which can lead to overheating the amplifier or further damage.
If you want to know about overheating amplifiers, I wrote a short article about it, so check it out.
Low-impedance speakers can force amplifiers to work too hard.
As a result, its fuse can blow, or the protection circuit will be activated, and the amp will be shut down to protect other parts of the audio system. In extreme cases, an overloaded amplifier can blow.
When designing the car audio system, you must match the speakers’ impedance with the amplifier.
But, because of many different installation types in the car audio, it is not always possible to have all components with the same 2 or 4 ohms.
Further down in this article, we will go through different impedance combinations.
Why Car Speakers Have Different Impedance?
We often wonder why some speakers have 4 ohms and others 2 ohms. This depends primarily on the speakers’ requirements regarding the quality of produced sounds and efficiency.
The only constant in the car speakers is voltage, while power and impedance depend on each other.
In the case of coaxial speakers or a component system, the car amplifier, when connected to the crossover, recognizes the impedances of the whole set and not individual speakers, which can be different in reality.
4 Ohm speakers will demand less current from the amplifier than a similar 2-ohm speaker.
At the same time, higher impedance means less distortion in the amp and more stable current flow. However, an increasing number of modern amplifiers can remain stable while delivering large amounts of power to speakers with low impedance.
The significant advantage of having less impedance is more power coming from the amplifier, which is important inside a noisy car.
The road or wind noise has to be compensated by the better speakers’ performance; this is where low-impedance speakers will perform better.
Can I Use 2 Ohm Amp With 4 Ohm Speakers or Vice Versa?
In most cases, we should aim for speakers’ impedance to match amplifiers, so when you have a 4-ohm amp, buy all speakers also 4 ohms.
But when you have designed a sound system with correctly calculated all resistance, these values can be different.
You can also connect 2-ohm speakers to a 4-ohm amplifier, but in order not to damage it, remember that 2-ohm speakers should have half of the amplifier’s RMS power.
Otherwise, the amplifier will be overloaded with different impedance, and in extreme cases, transistors can blow.
For example, when you have a 2x120W amplifier working at 4 ohms, you can pair it with either 120W 4 ohm speakers or 2x60W 2 ohm speakers.
Both sets will drive the same current from the amplifier, but the 4-ohm speakers will make a better sound quality.
Can I Mix 2 Ohm and 4 Ohm Speakers?
Most cars have installed two pairs of speakers in front and at the back, but do they have the same impedance rating? The vast majority, yes.
When we install 4-ohm speakers, they can be from a different brand, have different sizes or power, and impedance can be different. However, this is rare.
When you wire 4-ohm front speakers and 2-ohm rear speakers to the 4-channel amplifier, you have to be careful with the power level of the lower resistance 2-ohm speakers to not overload transistors and not damage the amplifier.
Another point to consider is the volume level of these speakers.
As we already said, 2-ohm speakers can play louder with the same power, so in our example, when mixing 4-ohm and 2-ohm speakers, you can hear too much from the back of the car.
If you want a different impedance in the car’s front and back and you have one amplifier, make sure 4-ohm speakers have twice as much power as 2 ohms.
In this case, you will ensure leveling out amplifier output to all channels.
It is much easier to manage different speakers’ impedance when your amplifier is designed to support 2 and 4 ohms on various channels.
In those cases, you only have to match the speakers’ power to the max amplifier output, and you will be okay.
Nevertheless, the best and safest way is to use all speakers in the car with the same (either) impedance. Then, your system will be stable, and you will only have to make a few adjustments to make it work.
How to Connect 2 Ohm Subwoofer and 4 Ohm Subwoofer?
Subwoofers are different, and when you see a typical car audio system, the speaker with other (usually lower) impedance will be the subwoofer.
They can work with 4, 2, or even 1 ohm in some cases and can have either one or two voice coils, so the number of variations in subwoofer connections is much higher than for the typical car speakers.
The most significant factor in the subwoofers is their ability to create loud and strong bass, which requires a lot of power.
The more powerful the subwoofer, the lower impedance it will have.
A 2-ohm subwoofer will play louder than 4 ohms with the same amount of power, but how strong bass will be generated also depends on the enclosure type.
To make a loud bass in your car, buy a 2-ohm subwoofer and a large power station made in D-class to supply enough current.
However, with the impedance reduction, you also reduce the quality of the bass, so you have to prioritize either music quality or loudness.
A similar approach is for subwoofers with dual voice coils. Although you physically have one speaker, the connection with the amplifier is the same as for the two independent woofers.
Depending on how you will connect it, you will determine the overall resistance of the dual voice coil subwoofer.
When you connect both 2-ohm voice coils in series, the total impedance will double, and it will become one 4 ohm speaker, or when you make parallel wiring, the impedance will be divided and will be 1 ohm.
To decide about subwoofer impedance, you have to decide which bass quality you want to achieve, and this is the starting point. For example, if you wish to hear high-end perfect kicks with a moderate volume, go for a 4-ohm subwoofer.
Doing so allows you to connect several subwoofers in the car and further increase the quality of the lowest sounds.
On the other hand, if you want to create thunders in your car and make it shake with every kick, you should consider a 2 ohm subs or even 1-ohm.
And for even more bass, you can connect multi subwoofers in parallel to reduce impedance and make them play even louder, but this approach is suitable when the decibels are the only priority.
Can I Replace 2 Ohm Speakers With 4 Ohm Speakers?
Generally, you should be fine when replacing 2-ohm speakers with 4-ohm speakers. But keep in mind that 2ohm and 4ohm speakers have different power requirements.
4-ohm car speakers usually have a lower power rating than 2ohm speakers because they’re less efficient at converting an electrical signal into sound.
When replacing speakers, we are not always checking impedance carefully, and new ones can be different from old speakers.
This simple overlooking can cause damage when replacing 2-ohm speakers with 4 ohms (or vice versa) that have the same power because they can overload the amplifier.
If the amp was not designed to work with lower impedance, such a change could cause the amplifier to overheat or other damage to the car audio system.
In the vice versa scenario, when we increase the speakers’ impedance, all audible sounds will become quieter, and although you will not damage the system, this change will not make you happy.
Can I Use the Car Radio to Power 2 Ohm and 4 Ohm Speakers?
You can use your head unit to power 2 ohm and 4-ohm speakers. But you should know that playing 2ohm speakers on a 4 Ohm amp will consume more power than usual because 2 Ohm speakers require more energy to play at the same volume as 4-ohm speakers.
Conclusion
2 Ohm and 4 Ohm Car Speakers have several differences. 2 Ohm speakers typically need more power to reach the same volume as higher resistance 4 Ohm speakers, but they are better suited for a louder bass sound.
You should always check the power ratings before replacing car speakers and make sure that the impedance of new ones will not overload the amplifier.
And, if your amp was not designed to work with lower impedance, make sure you don’t replace 4 Ohm speakers with 2 Ohm ones.
When you want to use car speakers of a different impedance, do not connect different ones to the same left / right channels.
Also, when you have four speakers powered by one amplifier, ensure all have the same impedance. Otherwise, the amp can likely get damaged.
FAQ
How Many Ohms Are Car Speakers?
The most common car speakers are 4 ohms. However, there are also lower-impedance car speakers available with either 3 ohms or 2 ohms.
We know from the Ohm law that the lower the number of ohms, the easier it is for electricity to flow through.
In other words, a 2-ohm speaker will require less power from your amplifier than a 4-ohm speaker to produce the same volume.
What Does Ohm Mean in Car Speakers?
The impedance of a car speaker measures how much the speaker resists the current flow.
A lower impedance speaker will require less power from your amplifier to produce the same volume as a higher impedance speaker.
How to Wire 4 Ohm Speakers to 2 Ohm Amplifiers?
The best way to wire 4 ohm speakers to 2 ohm amplifiers is to connect them in parallel.
This will result in a 4 ohm load on the amplifier, which is the recommended load for most car amplifiers.
This method however is standard only in the case of the subwoofers unless you use two separate 4 ohm speakers per each 2ohm channel in the amplifier.
What is Better, 2 Ohm or 4 Ohm Speakers?
Some people prefer the sound of 2 ohm speakers because they tend to have more bass, while others prefer the sound of 4 ohm speakers because they tend to have more treble.
Choosing speakers of any impedance is ultimately a personal preference and depends on the amplifier you are using.