Last Updated on: May 16, 2022
Impedance is a common term for anyone who has bought or configured their car audio system. The impedance is usually indicated on the speaker (or amplifier unit) with ohms as the measuring unit.
To determine what hits harder 1 Ohm or 4 Ohm, we’ll need to understand first what impedance is and why it matters when setting up your speakers.
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Main Differences Between 1 Ohm vs 4 Ohm Car Speakers
The main differences between the 1 Ohm versus the 4 Ohm speakers are:
- 1 ohm car speaker has less resistance, whereas a 4 ohm speaker has more resistance.
- 1 ohm car speakers are not typical for car audio systems, whereas 4 ohm speakers are the norm.
- The 1 Ohm impedance speaker decreases in sound quality at a high volume, whereas the 4 ohm impedance speaker delivers better sound quality.
- 1 ohm speakers require more wattage from the amplifier for power, whereas the 4 ohm speakers require less wattage to operate.
What Is Impedance?
Speaker impedance is a measure of the electrical resistance from the speaker’s voice coil against the flowing current of the amplifier.
Generally speaking, impedance is the amount of power a speaker can transform into sound.
We use ohms to measure impedance, and we would need to match the amplifier’s impedance rating with the speakers for performance.
An easy way of understanding impedance is to relate it to how water flows through a pipe. For example, we can visualize your car speaker as a pipe and the audio signal, or electric current, as water flowing through the tube.
A wide diameter pipe allows water to flow more freely and handles more water than a narrow pipe. Speakers with a low impedance, such as the 1 ohm speakers, are like wide diameter pipe that allows more electrical current to pass through them.
Car speakers often come with 1 Ohm, 2 Ohm, 4 Ohm, and 8 Ohm impedances and differ in price, brand, load power, and audio quality.
When comparing the 1 ohm vs 4 ohm sound quality, the low impedance subwoofer requires more power from the amplifier and is louder than the high impedance sub.
Similarly, a high impedance amplifier will deliver less power to a car speaker than a low impedance amp.
While the 1-ohm subwoofer is louder, the 4-ohm speaker will deliver less distorted sound at a high volume. However, match your speaker’s impedance with the correct amplifier to achieve good sound quality.
Speaker Impedance vs Frequency
Speaker impedance is not static, and it changes as the sound frequency goes up and down. In other words, the impedance of a speaker is directly proportional to its frequency.
Speakers generally deliver sound within a broad frequency band due to the inductance of the voice coil.
Therefore, when frequency goes up, the speaker impedance increases in proportion. For example, a speaker may have 8 Ohms at 41Hz and 3 Ohms at 2000Hz.
Additionally, there isn’t a particular frequency that one can use to determine the speaker’s impedance, unlike other metrics such as power and sound output.
Therefore, the impedance value we usually see on the speaker is an average of its operating performance.
What is an Impedance Switch?
Some modern amplifiers may feature an impedance selector switch that allows you to switch between different impedance settings. The switch helps protect the receiver from overheating or damaging its output transistors with excess current flow.
Plus, it offers flexibility with speakers with different impedance ratings. However, the switch also reduces the amp’s power capability, resulting in reduced audio quality at low frequency.
For example, an amplifier with the switch at 8 Ohm position will deliver a louder, more dynamic sound because the power supply has more voltage. The same amp driving a 4 Ohm load will push out less power and would be suitable to use for a higher impedance speaker.
However, if you use the amp with the switch at the 4 Ohm position with a lower impedance subwoofer at a high volume, the speaker puts more power demand on the amp and may cause it to clip.
Therefore, I recommend keeping the switch at its highest impedance setting and matching it with the appropriate subwoofers. Plus, make sure your receiver has plenty of ventilation to dissipate heat when it runs warm.
Why Is Speaker Impedance Important
Speaker impedance is important because it also determines the amount of wattage from the amplifier. Amplifier wattage increases or decreases depending on the speaker’s impedance.
For example, a 100 watts amplifier will deliver more power to a 1 Ohm speaker than a 4 Ohm speaker. Therefore, one needs to consider the amplifier’s capacity when matching it with the speaker to avoid overloading it.
If the amp delivers more power to a speaker than it can handle, it will blow up. Similarly, if the amplifier is overloaded to power a low impedance speaker, it will get damaged.
Besides matching wattage between the speaker and amplifier, one also needs to complement their nominal impedance.
The amp needs to have 50% more power than your speaker to work continuously without a problem.
For instance, if your 4-ohm speakers have a 500 watts power capacity, you need an amplifier that delivers at 750 – 800 watts per channel at 4-ohm impedance.
However, avoid pairing a low impedance speaker with a high impedance one. For example, matching a 1 Ohm sub with a 4 Ohm amp means the amp has to overwork to deliver more wattage than its capacity to power the subwoofer.
Fun Fact: You could still enjoy crystal-clear music and audio on your car speakers even without an amplifier! Research on how to amplify speakers without amplifier and enjoy your sounds without purchasing expensive equipment!
How to Vary Speaker Impedance
Speaker impedance is not static, and it changes automatically depending on the speaker’s frequency and voice coil inductance.
On the other hand, you can also alter impedance by wiring multiple speakers in series or parallel combinations to one amp.
To achieve this, you’ll need to understand how to calculate the load output of the speakers depending on impedance. This online calculator can help you figure it out.
Meanwhile, let us look at the series vs parallel speaker wiring combinations:
In this combination, the subwoofers connect end-to-end to form a daisy chain. The positive end of one speaker connects to the negative end of the next one, which increases the overall impedance of the entire circuit. The cumulative value will determine the load and audio quality of the speakers.
For instance, two 2 ohms speakers connected in series will deliver 4 ohms to the amp. Also, a 2-ohm speaker and 4-ohm speaker will combine to present 6 ohms.
In a parallel combination, the positive and negative ends of the subwoofers, separately. This combination results in the cumulative impedance decreasing fractionally depending on the number of speakers in the circuit.
For example, four 4 ohms speakers in parallel combination results in an overall impedance of 1 ohm. We divide the 4-ohm impedance rating by the number of subs in the circuit.
If the speakers have a different individual impedance rating, we use the inverse sum of the reciprocals calculation formula.
So, with a 2 ohm, 4-ohm speaker, and 8-ohm speaker in parallel wiring, we would get the sum of the divisions of each speaker impedance by one.
In our case, the value comes to 0.875. Afterward, we then divide this value by one to get 1.14 ohms.
Generally, the 1 Ohm subwoofer will hit harder than the 4 Ohm sub because it delivers more sound output than the 4 Ohm sub at the same wattage.
While the low impedance sub produces a louder sound, the high impedance subwoofer has better sound quality.
Additionally, the 1 Ohm speaker costs more and puts more load on the amplifier when compared. On the other hand, the 4 Ohm speaker has better amp efficiency, making it preferable for car audio systems than the 1 Ohm.
Fun Fact 1: Despite the power ratings of your car speakers, you might still experience problems like music distortion and hissing. Be on the lookout for signs of a bad car amplifier and have it repaired immediately!
Fun Fact 2: Car speakers come in a variety of sizes? Do they matter? Research about car speakers sizes chart and choose what size fits you and your amplifier needs.
One of the main reasons people install 1 Ohm subs in their cars is their powerful sound output.
However, when comparing the 1 ohm vs 4 ohm sound quality, the low impedance speaker is louder and more powerful, while the high impedance sub has better audio quality.
Other factors you should consider include price and amplifier wattage. The 1 Ohm sub costs significantly more and requires more amplifier load than the 4-ohm speaker.