Ohms, impedance, and resistance –are the three most recurring terms when it comes to understanding the inner workings of a speaker. Although these specifications get overlooked by many consumers, it’s important to know them in order to get the best quality speakers.
So, what does ohm mean for speakers? And why is impedance important?
To put it simply, ohms is the unit for resistance in the electrical flow of the audio signal in speakers. And impedance is the measure of a unit’s opposition to an alternating current.
However, to fully understand the importance and purpose of these terms, we need to look into their detailed meanings and their significance in the audio output of speakers.
What Are Ohms?
In electricity, there are four known elements: watts, volts, amps, and ohms. Ohms are a measure of resistance to electrical flow, which is marked by the symbol ‘Ω.’
As the resistance increases, the number of ohms increases as well. However, a lower number of ohms actually means a greater and more powerful signal.
Think of this as water passing through a pipe. If water is the current and the resistance is the width of the pipe, then a lower ohm count means that more “water” will pass through without resistance as the pipe is wide. And if there are more ohms, less water will pass through and with greater resistance.
The speaker and amplifier work hand in hand. In order to avoid overloading the speaker, the amplifier never transmits more audio signal (in ohms) than the speaker can handle. So, if a speaker is an 8-ohm system, the amplifier will also transmit 8-ohms of the audio signal.
Therefore, the amplifier and speaker should have the same ohm count. If there is an imbalance or “mismatch” in the ohm count for either of these units, a number of problems can occur, such as no audio output, poor audio quality, internal speaker damage, or even short circuits.
What Is Impedance for Speakers?
The load a speaker expects from an amplifier is called its impedance. To be more specific, speaker impedance refers to the current transmitted by the amplifier, which is in correlation to the resistance that the speaker offers.
As the output current of an amplifier is not DC (such as from batteries), it is AC, which results in the resistance being called ‘impedance.’ So, impedance is the pairing of DC resistance with any reaction in an AC circuit.
Speaker impedance, therefore, directly affects how much audio signal is taken from the amplifier. It is also measured using the ohms unit.
If you want a more thorough and in-depth look into impedance along with the technical matters of speaker function, check out this video.
What Is the Difference Between Impedance and Resistance?
Most people tend to confuse impedance with resistance. The main difference between these two is that impedance changes as the frequency of signals changes, but resistance does not.
The audio signal transmitted from an amplifier carries a number of different frequencies, so the speaker impedance is pushed to change constantly. But, this does not mean that the speaker impedance cannot be measured.
The impedance of a speaker is found using its “nominal” impedance. This is the average result of the sum of the lowest impedance values.
Resistance, on the other hand, is responsible for the one-directional flow of the current and its speed of transmission. In comparison, impedance is just the measure of a unit’s opposition to an alternating current.
Why Is the Impedance of Speakers Important?
When looking for a speaker, most consumers overlook the impedance. But, the impedance is what affects all other important features of a speaker, such as bass quality, audio output, and volume.
In summary, these are the factors that are affected when the impedance of speakers is not adequate:
Speaker Efficiency
As we’ve mentioned, a mismatch between the amplifier and the speaker throws off the impedance of the speakers. This means that both the amplifier and speaker unit have to have the same ohm count, for instance, 8 ohms or 4 ohms.
If the ohm count is different for either the speaker or amplifier, the power imbalance will cause multiple issues, such as audio distortion, crackling, poor bass quality, or even short circuits.
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Overall Sound Quality
The crispness of the audio and the power of the bass all relies on the impedance of the speakers. Basically, the impedance rating of a speaker tells you how hard it is to power the unit.
The lower the impedance rating, the more efficiently the electric and audio signals are passed through the speaker. So, it’s not only important to look at the impedance of the speaker but also to go for a lower rating for the best sound quality.
Volume and Tune
Speakers with lower impedance ratings require less power from an amplifier to produce efficient sound and bass. Likewise, most amplifiers will work at their best when they have a low impedance rating.
In fact, speakers/amplifiers at a higher impedance are more likely to be out of tune and have poor volume.
But this does not mean that high-impedance speakers and amplifiers are completely ruled out. We recommend pairing high-impedance speakers (8 ohms and up) with amplifiers that have the same impedance rating. And speakers with less than 4 ohms are best paired with a low-impedance amplifier.
An imbalance in impedance also disrupts the frequencies of the electrical signals through the speakers. This can affect the volume in most electric speakers by changing the direction of signals or cutting them off abruptly. As a result, the volume can come out muted or distorted.
Frequently Asked Questions
1. Does speaker impedance affect the sound?
Yes, speaker impedance can affect sound quality. If there is a mismatch between the impedance of a speaker and the amplifier or if the speaker components are changed without adjusting the impedances, it will decrease the efficiency of the unit.
2. How does speaker impedance affect volume?
Speaker impedance can affect the volume of electrical speakers by disrupting their audio output. The disturbance in the transmission of audio and electrical signals caused by an imbalance in the impedance causes distorted sound and volume.
3. Can you change the impedance of the speakers?
Yes, it is possible to change the impedance of speakers. You need to replace a number of components to bring about a noticeable change. If you want to add more bass to the audio output, you can just try switching these simple components instead of more intense replacements to change the impedance.
4. What ohms are most speakers?
The most commonly used speakers range between 4, 6, or 8 ohms and do not go beyond or lower than that. Usually, speakers can be found ranging from as low as 2 ohms to more than 8 ohms.
5. Are higher ohms better for speakers?
Higher ohm speakers are better than lower ohm speakers in terms of crisp sound quality. But lower ohm speakers provide a better bass and more speaker efficiency. Plus, lower-ohm speakers do not get as hot as higher-ohm ones as they require less power to generate sound.
Conclusion
To answer ‘what does ohm mean for speakers’ in summary, it is the unit for resistance in a speaker, which indicates the impedance for the speaker.
The ohm count, more specifically the impedance, can give you more in-depth knowledge about the speakers’ sound quality, bass and volume, speaker efficiency, and more.
Instead of individually going through factors related to audio output, it’s best to look into the impedance rating of a speaker before purchasing it to make sure it functions effectively.