When it comes to choosing between 4 ohm and 8 ohm speakers, it’s important to understand the differences between the two before you start spending money or connecting components up. The “ohm” is an important feature of a speaker, but what does it mean, and how do you use it and make a decision?
8 Ohm speakers are better for most home-theater applications, while 4 ohm speakers lend themselves to higher-end professional setups and auto applications. The speaker and amp’s ohms (impedance) need to match or damage can occur, and sometimes the ohms across a circuit can be adjusted using wiring.
While 4 ohm speakers may offer more volume quality, they can be quite expensive and require more power to operate. On the other hand, 8 ohm speakers are more affordable and consume less power, but they may not sound as good as 4 ohm speakers depending on the use case. There are a few details you need to know to make this decision, but only a few, so let’s get started!
What is an “Ohm”? (Understanding Impedance)
So, since this discussion is happening in terms of “ohms,” we’d better start by knowing what an “ohm” is and what it means for speakers. It must be something we need to know to get this right, otherwise speaker manufacturers would just call speakers “small” “medium” and “large,” so, something is going on here.
What is an Ohm? It’s a unit of measure that is specifically measuring something called impedance, which is a feature of any speaker. So, let’s tackle that next.
Impedance Defined
Impedance is the measure of resistance to an alternating current (AC) flow. It is measured in ohms and is a crucial factor when it comes to audio equipment.
Impedance is not the same as resistance, which is the measure of resistance to direct current (DC) flow. The impedance of a speaker is determined by the voice coil’s resistance, the speaker’s inductance, and the speaker’s capacitance.
Impedance and the Amplifier
Speaker impedance is a critical factor when it comes to matching speakers and amplifiers. A speaker’s impedance level determines how much power the amplifier can deliver to the speaker. If the impedance level is too low, the amplifier may overheat and become damaged.
If the impedance level is too high, the amplifier may not be able to deliver enough power to the speaker, resulting in poor sound quality.
Impedance Matching
When comparing 4 ohm vs. 8 ohm speakers, it’s important to note that 4 ohm speakers require more power than 8 ohm speakers. This means that you need a more powerful amplifier to drive 4 ohm speakers. However, 4 ohm speakers tend to sound better than 8 ohm speakers, especially in high-end models.
When connecting speakers to an amplifier, it’s essential to match the impedance levels correctly. If the impedance levels are not matched correctly, it can result in poor sound quality or damage to the equipment. We’ll go into more detail on this further down, but for now this is the basic situation.
8 Ohm & 4 Ohm Speakers Compared
When it comes to choosing between 4 ohm and 8 ohm speakers, there are a few key differences to consider. In this section, we’ll compare the two types of speakers in terms of sound quality, loudness, speaker efficiency, and cost considerations.
Before we explain some of these features in more detail, though, here’s a handy table you can use as a shortcut:
| Pros of 4 Ohm Speakers | Cons of 4 Ohm Speakers | Pros of 8 Ohm Speakers | Cons of 8 Ohm Speakers |
|---|---|---|---|
| Lower impedance results in higher loudness (at the same power) | Can sometimes produce more distortion at high volumes | Generally smoother, more balanced sound | Lower loudness than 4 ohm speakers (at the same power) |
| More efficient at converting electrical power into sound | May require more power to drive | Can be easier to find and more affordable | May require higher quality components to drive effectively |
| Can be a good choice for high-powered setups | May not be compatible with as many amplifiers | Can be a good choice for lower-powered setups | May not be as loud as 4 ohm speakers (at the same power) |
And if you’re more interested in a car audio project, be sure to have a look at our article on the differences between car and home speakers, and for more thorough background skim our article on what makes a subwoofer different than normal speakers.
Sound Quality
In terms of sound quality, both 4 ohm and 8 ohm speakers can deliver excellent performance. However, there are a few differences to keep in mind. Generally, 8 ohm speakers tend to have a smoother, more balanced sound, while 4 ohm speakers can sometimes produce more distortion at high volumes.
That being said, there are many high-quality 4 ohm speakers on the market that can deliver excellent sound without any distortion issues.
Loudness
One of the main differences between 4 ohm and 8 ohm speakers is their loudness. In general, 4 ohm speakers are louder than 8 ohm speakers, all other things being equal. This is because 4 ohm speakers require less voltage to produce the same amount of power as an 8 ohm speaker.
However, keep in mind that a speaker’s loudness is also affected by other factors, such as its sensitivity rating and power handling capabilities.
Speaker Efficiency
Speaker efficiency refers to how well a speaker converts electrical power into sound. In general, speakers with lower impedance (such as 4 ohms) tend to be more efficient than speakers with higher impedance (such as 8 ohms).
This is because lower impedance speakers allow more electrical current to flow through them, which can result in more sound output for the same amount of power. However, keep in mind that speaker efficiency is just one factor to consider when choosing a speaker, and there are many other factors that can affect a speaker’s overall performance.
Cost Considerations
When it comes to cost, there are a few things to keep in mind. In general, 8 ohm speakers tend to be more affordable and easier to find than 4 ohm speakers. This is because 8 ohm speakers are more commonly used in home audio setups, while 4 ohm speakers are more commonly used in professional audio setups.
However, keep in mind that there are many high-quality 4 ohm speakers available, and the price difference between the two types of speakers may not be significant in all cases.
In terms of cost-effective solutions, one option is to use a speaker impedance matching device to connect 4 ohm speakers to an amplifier that is designed for 8 ohm speakers. Another option is to use a subwoofer or other type of speaker that is specifically designed for use with 4 ohm amplifiers.
Tips for Upgrading Your Home Theater Setup with Speaker Impedance in Mind
When it comes to upgrading your home theater setup, speaker impedance is an important factor to consider. Here are some tips to keep in mind when upgrading your speakers:
First, make sure to match the impedance of your speakers with that of your amplifier. AS we’ve discussed, sing speakers with a lower impedance than your amplifier can cause your amplifier to overheat and potentially damage your equipment.
On the other hand, using speakers with a higher impedance than your amplifier can result in lower volume levels and reduced sound quality.
Second, consider the size of your room when selecting speaker impedance. Larger rooms may require speakers with lower impedance to achieve higher volume levels, while smaller rooms may benefit from speakers with higher impedance to avoid overpowering the space.
Finally, keep in mind that speaker impedance is not the only factor to consider when upgrading your home theater setup. Other factors such as speaker size, placement, and frequency response should also be taken into account to achieve the best sound quality.
When upgrading your speakers, we recommend checking out the Polk Audio Signature Series S60 Floor Standing Speaker (on Amazon) for a high-quality option that has 8 ohm speakers, but which advertises easy use with 4 or 8 ohm amplifiers. (This is achieved through the wiring – more on that a bit lower down).
Matching Amplifiers and Speakers
When it comes to matching amplifiers and speakers, there are a few key factors to consider. In this section, we’ll cover amplifier power and speaker sensitivity, impedance matching, and what happens if the amp and speakers don’t match impedance.
When connecting speakers to an amplifier, it’s important to make sure that the impedance of the speakers matches the impedance of the amplifier. For example, if you have an amplifier with an output impedance of 8 ohms, you should use speakers with an impedance of 8 ohms. Using speakers with a different impedance can cause the amplifier to overheat or even damage the speakers.
What Happens if the Amp and Speakers Don’t Match Impedance?
If the amp and speakers don’t match impedance, you may experience a number of problems. If the speakers have a lower impedance than the amplifier, the amplifier may overheat or even shut down. If the speakers have a higher impedance than the amplifier, the sound may be weak and distorted.
In general, it’s best to match the impedance of the speakers to the impedance of the amplifier. If you’re not sure what the impedance of your speakers or amplifier is, check the user manual or contact the manufacturer for more information. Typically, the receiver’s speaker connections will be clearly labelled with their ohm capacity.
How To Adjust Speaker/Amplifier Impedance Matching Through Wiring
When it comes to wiring speakers, there are two primary options: series and parallel. Let’s take a closer look at each of these wiring connections and how they can be used to adjust the speaker/amplifier impedence balancing.
Series Connection
In a series connection, speakers are connected end-to-end, with the positive terminal of one speaker connected to the negative terminal of the next. This connection method increases the overall impedance of the speaker system. For example, if we have two 4-ohm speakers in series, the total impedance of the speaker channel would be 8 ohms.
One thing to keep in mind is that the total power output to the series speaker load would be limited. In the example above, the total power output would be only 50W maximum, which would be divided between the two speakers. So, each speaker would receive 25 watts per speaker.
Parallel Connection
In a parallel connection, speakers are connected side-by-side, with the positive terminals of all speakers connected together and the negative terminals of all speakers connected together. This connection method decreases the overall impedance of the speaker system.
For example, if we have two 4-ohm speakers in parallel, the total impedance of the speaker channel would be 2 ohms.
One thing to keep in mind is that the total power output to the parallel speaker load would be increased. In the example above, the total power output would be 100W maximum, which would be divided between the two speakers. So, each speaker would receive 50 watts per speaker.
It’s important to note that when wiring multiple speakers in series or parallel, the total power load (in watts, as opposed to impedance) on the amplifier must also be taken into consideration. If the load is too high, it could damage the amplifier.
We recommend the Dayton Audio B652-AIR 6-1/2″ 2-Way Bookshelf Speaker Pair with AMT Tweeter (on Amazon) for those looking for high-quality speakers that can be wired in either series or parallel. These are actually 6ohm units that are compatible with 4 or 8-ohm receivers.
Applications
Let’s look at a few of the actual use cases where you may be making decisions around using 4 vs 8 ohm speakers.
Home Theater and Professional Audio
When it comes to home theater and professional audio systems, the speaker impedance plays an important role in achieving high-quality sound. Most home theater and professional audio systems use 8-ohm speakers, which are more power-efficient and produce less heat. However, some high-end systems may use 4-ohm speakers, which require a high-quality amp to achieve optimal performance.
Obviously personal preference and budget also play a role in choosing the right speaker impedance for your home theater or professional audio system.
And after you pick the right speaker, you’ll probably want to have a look at our articles on placing a subwoofer on it’s side and whether it should be in front of or behind you to get the most out of your unit.
Speaker Impedance and Subwoofers
Subwoofers are an essential part of any audio system, especially for music enthusiasts. When it comes to subwoofers, the speaker impedance can affect the overall sound quality just like it can for any of the other speakers in your system.
You want to pick a sub and an AV that has a sub-out channel that is set to the right ohms, OR use speaker wire to finagle the circuits impedance to where you want it.
Car Audio Systems
When it comes to car audio systems, the speaker impedance can affect the overall sound quality and power consumption. 4 ohm speakers are somewhat more interesting in this use case because cars are, in general, smaller than home theaters (haha), so smaller speakers make more sense.
And especially if you can use smaller speakers that can also get louder, like 4 ohm speakers, suddenly the car-audio applications start to look a lot simpler with 4 ohm speakers. Again, have a look at our car-speaker-audio article for more discussion in this direction.
Common Myths About Speaker Impedance and the Truth Behind Them
When it comes to speaker impedance, there are many myths that have been circulating around for years. In this section, we will debunk some of the most common myths about speaker impedance and provide you with the truth behind them.
Myth #1: Lower impedance speakers are better than higher impedance speakers.
Many people believe that a lower impedance speaker is better than a higher impedance speaker because it can handle more power. However, this is not entirely true. While it is true that lower impedance speakers can handle more power, they also require more current to operate. This means that they can put a strain on your amplifier and may cause it to overheat or even fail.
Myth #2: A speaker with a higher impedance rating will sound worse than a speaker with a lower impedance rating.
This is also not true. The impedance rating of a speaker has nothing to do with how good it sounds. In fact, some of the best sounding speakers on the market have a high impedance rating. The impedance rating simply tells you how much resistance the speaker has to the flow of electrical current. A higher impedance speaker will have more resistance, which means that it will require more voltage to produce the same volume as a lower impedance speaker.
Myth #3: You can use any amplifier with any speaker.
This is a dangerous myth that can cause serious damage to your equipment. Matching your amplifier to your speakers is crucial to ensuring that your system sounds its best and operates safely.
If you use an amplifier that is not powerful enough for your speakers, you may end up damaging your speakers or your amplifier. On the other hand, if you use an amplifier that is too powerful for your speakers, you may end up damaging your speakers as well. It is important to match your amplifier to your speakers based on their impedance rating and power handling capabilities.
Which Speaker Is Right For You?
Perhaps by now you have a feeling about which speaker option is right for you. Whether you’re building a home theater or upgrading an existing one, 8 ohm speakers are a great default, but ALL speakers should be measured against the capabilities of the matched receiver.
You can use speaker wiring solutions to manage the impedance of a circuit by wiring speakers in parallel or series, which will allow you to use some mix-and-match components here and there or plan an even more involved system.
While 8 oh speakers seem to be the best bang-for-your-buck for most people, some professionals (and especially audio applications) may benefit more from 4 ohm speakers in the end.
