What Speaker Impedance Means and Why It Matters
There is a specification for impedance measured in ohms (symbolized as ) that can be found on practically every speaker or set of headphones you can buy.
The packaging and product instructions that come with the products rarely explain what impedance is or why it is important to you.
Impedance is comparable to excellent rock ‘n’ roll.
Understanding everything about it is difficult, but you do not need to understand everything in order to “get” what is being discussed.
About Speaker Impedance
Many audio writers utilize the analogy of water running through a pipe when discussing concepts like as watts, voltage, and power because it is an analogy that people can envision and relate to.
Consider the speaker to be similar to a pipe.
When you play music, the audio signal (your song) simulates the flow of water through the pipe.
The greater the diameter of the pipe, the more easily water may flow through the pipe.
Larger pipes can also accommodate a greater volume of water running through them.
As with a larger pipe, a speaker with lower impedance enables for more electrical signal to pass through while also making it easier for the signal to flow more freely.
As a result, you’ll see amplifiers rated to deliver 100 watts at 8 ohms impedance, or 150 or 200 watts at 4 ohms impedance, among other things.
The lower the impedance of the speaker, the more easily electricity (or the signal or music) passes through the speaker and into the listening environment.
A large number of amplifiers are not intended to be used with 4-ohm speakers.
As an analogy, you can increase the size of the pipe, but it will only carry more water (audio) if you have a pump (amplifier) that is powerful enough to produce the additional flow of water.
Does Low Impedance Guarantee High Quality?
If you utilize lower-ohm speakers with equipment that is not capable of supporting them, you may find yourself having to turn the amplifier all the way up, which can cause harm to the equipment.
When a receiver or amplifier is not up to the task, using speakers and amplifiers that are not properly matched can produce problems.
Any modern speaker can be connected to practically any modern amplifier, and you’ll have more than enough volume to fill your living room.
Exactly how does a 4-ohm speaker differ from a 6-ohm or an 8-ohm speaker is a matter of debate.
It’s not much—just the fact that the impedance is low is sometimes indicative of how much fine-tuning the engineers did when they developed the speaker.
A speaker’s impedance varies depending on how high or low the pitch of the sound is (or frequency).
In the case of a conventional bass guitar, the impedance of the speaker might be 10 ohms at 41 hertz (the lowest note on the instrument).
It is possible that the impedance is as low as 3 ohms at 2,000 hertz (the upper range of a violin).
The impedance specification displayed on a speaker is only a rough average of several different values.
Most demanding speaker engineers like to equal out the impedance of their speakers in order to provide consistent sound quality throughout the whole audio range.
A speaker engineer might employ electrical circuitry to flatten areas of high impedance, just like someone might sand a piece of wood to remove the high ridges of grain.
4-ohm speakers are prevalent in high-end audio, but they are uncommon in mass-market audio because of the extra attention they require.
Can Your System Handle It?
Before purchasing a 4-ohm speaker, ensure that the amplifier or receiver is capable of handling it.
However, if the amplifier or receiver manufacturer publishes power levels in both 8 and 4 ohms, you may rest assured that your purchase will be safe.
Most independent amplifiers without a built-in preamp or tuner, as well as the majority of high-end A/V receivers, are capable of driving 4-ohm speakers.
It is possible that a low-cost receiver will not be the ideal match for 4-ohm speakers.
It might work fine at low volume, but turn the volume up and the amplifier may not have enough power to power the speaker.
You may cause the receiver to shut down for a short period of time, or you may completely destroy the receiver.
About the Impedance Switch
Several amplifiers and receivers are equipped with an impedance switch on the back, which may be used to toggle between ohm and kilohm settings.
The problem with using this switch is that impedance does not have a flat setting; instead, it has a curve that changes over time.
Intentionally crippling the full capabilities of your amplifier or receiver by using an impedance switch to “match” your equipment to your speakers is against the rules.
Keep the impedance at its highest setting and get speakers whose impedance settings correspond to those of your equipment for the optimum performance.
Impedance of Car Speakers
4-ohm speakers are the standard in automobile audio.
This is due to the fact that automotive audio systems operate on 12 volts DC rather than 120 volts AC.
It is possible to get more power out of a low-voltage vehicle audio amplifier by using car audio speakers with a 4-ohm impedance.
Car audio amplifiers are intended for use with speakers that have a low impedance. So turn up the volume and take it all in.