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.
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 can sometimes mean more volume and a higher sound level if the energy sent manages to raise the sensitivity of the speaker.
Plus, a 4 Ohm speaker can be louder at a certain volume level but not necessarily louder since you will most likely get more headroom with a more powerful amplifier when using a 4 Ohm speaker.
Speaker sensitivity is measured in Decibels (dB). It tells you how loud the speaker can get and how much more you can amplify that loudness with an amplifier.
4 Ohm vs 8 Ohm: Audio Quality
Audio quality has nothing to do with speaker impedance, rather it relates to the receiver you set your speaker with. As long as you are using compatible equipment and can match the impedance of your speaker to the impedance of your amplifier, then you shouldn’t have any trouble with sound quality.
Most speakers are rated within 4 to 8 Ohms, with 6 and 8 Ohms speakers being the most common. If your speaker is rated at 6 or 8 Ohms then you should have little to no problems with a matching receiver as most channel amps are rated as compatible with 6 and 8-ohm speakers.
If your speaker has a 4 Ohm nominal impedance rating, then you should match it with a capable amplifier that can drive adequate power to the speaker at a different frequency.
Once there is an impedance mismatch, you will start having problems with audio at higher volumes and may even start experiencing distortion at certain frequencies.
Together with increased noise levels, impedance mismatch can also lead your speaker/amplifier to overheat, causing frequent shutdowns and eventual damage to the equipment over time.
4 Ohm vs 8 Ohm: Speaker Cost
Most speaker manufacturers like to use4 Ohms Nominal Impedance in their high-end speakers, so one can generally assume that 4 Ohm speakers are more expensive.
Another thing to consider is the receivers/ amplifier that will be coupled with 4 Ohm speakers.
4 Ohm speakers will need powerful amplifiers to drive the load, so they will be more expensive than amplifiers you would easily couple with 6- & 8-Ohm speakers.
For basic home use, you may find more compatible and cheaper equipment in the 8 Ohm range but will have to carefully match 4 Ohm speakers to compatible amplifiers.
Do I Want 4 Ohm or 8 Ohm Speakers?
4 Ohm vs 8 Ohm speakers: which should you go for? It depends on what you can work with.
4 Ohm speakers are generally recommended for professionals who are willing to spend more on a capable amplifier. Make sure you match such speakers with compatible receivers with a similar impedance rating.
8 Ohm speakers are recommended for those who want to pick something off the shelf and just stick with it without much emphasis on the impedance load or the amplifier ohm load.
We still recommend you match the impedance speakers to amplifiers for best results.
The bottom line is that most 4 Ohm speakers offer the prospect of more robust sound, headroom, volume, and sound quality if you combine them with a capable amplifier. The ohm load of such speakers resists less electric signal (the music signal) but requires more power to drive the output.
If you are willing to spend money on powerful amplifiers for both 8 Ohm and 4 Ohm speakers, you can pretty much get decent sound output for both types of equipment.
4 Ohm vs 8 Ohm: Related Questions
Is It Harder to Drive 4 Ohm Speakers Or 8 Ohm?
It is harder to drive 4 Ohm speakers than it is to drive 8 Ohm speakers. This is due to the resistance caused by the impedance.
4 Ohm Ratings will allow the more electrical signal to flow to the speaker when compared to an 8 Ohm rating, but it will require more power to drive the 4 Ohm load because it poses less resistance.
Are Higher Ohms Better for Speakers?
Higher Ohms do not necessarily mean better speakers.
Ohms refer to the impedance rating of the speaker and the amount of electric signal allowed to flow through the circuit. Higher Ohms pose more resistance to electric signals, while lower Ohm load poses lesser resistance to the same electric signal.
Can I Use An 8 Ohm Speaker With A 4 Ohm Amp?
It is not recommended to use an 8 Ohm speaker with a 4 Ohm amp, as it will cause impedance mismatch, distorting sound and audio quality at higher volumes.
If you connect two 8 Ohm speakers in parallel you can reduce the impedance load and safely connect to a 4 Ohm amp.
Having cleared all misconceptions and half-truths concerning the debate around 4 Ohm Vs 8 Ohm we are confident you can now make an informed decision when it comes to choosing speakers.
You can easily determine which impedance levels are best for you, how much output power you can work with, and even decide how much amplifier power you need.
Our general advice is to choose what works best for you, and what you can afford. So, go ahead and make that informed decision, avoiding impedance mismatch at all costs.
Checkout similar guides for more professional advice to guide your decisions.