Are Car Speakers Polarity Sensitive? 9 Things You Must Know


It isn’t too uncommon for people to suddenly reverse their speakers’ wires, especially when the speaker wires are not labeled for polarity.

And when that happens, audio goes “out of phase,” and there will be an audible difference in the sound quality. This usually happens with sound systems at home, but you may be wondering if car speakers are also polarity sensitive?

Car speakers are polarity sensitive. Reversing the polarity will have an odd effect on car speakers, such that the soundwave produced by the speakers will be the opposite of what has been recorded. This creates an “out of phase” effect that damages the quality of the produced sounds.

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If you are using the built-in car speakers you got from your manufacturer, there shouldn’t be many speaker polarity problems because wires are supposed to have been configured the right way.

The problem comes if you intend to replace your car’s speakers. In such cases, it is important for you to know more about car speakers and how sensitive they can be to polarity.

What is the speaker’s polarity?

In case you didn’t know, soundwaves actually come with their own polarity, which is basically the series of positive and negative pressures they make in the air.

are car speakers polarity sensitive

Positive pressure in the air happens when the soundwave makes a change that is above the normal air pressure in the room. 

Meanwhile, a negative pressure happens when the soundwave makes a change that is below the normal air pressure in the room.

Soundwaves actually come in the form of an actual wave wherein the highs are the positive pressures, and the lows are the negative pressures. The sequencing is determined by which between the positive and the negative pressure comes first.

For example, when you strike a drum, the fact that the upper part of the drum moves down creates a negative pressure in the air, thereby making the first part of the soundwave negative, which is then followed by a positive pressure when the upper part of the drum begins to pop back up.

So, in other words, when we talk about the polarity of soundwaves coming from a speaker, we are talking about the wavelength created between the amplifier and the speaker.

Wires that connect both the amplifier and the speaker determine the polarity, so it is important to remember that amplifier’s positive terminal should always be connected with the speakers’ positive terminal. The same goes for the negative terminals.

And if we were to swap those, then the speakers would be in reverse polarity.

How do car speakers work?

Car speakers work in the way that electric current passes from the amplifier over to the speakers through a wire that connects them.

The amplifier is the one that first receives the electrical signal, and it will then allow it to pass to the speakers, which will then move forward and backward depending on the polarity of the signal it is getting from the amplifier.

So, basically, when you look at how car speakers work, they will be in the default position and will be at rest whenever an electrical current doesn’t pass through them.

However, when they receive a signal from the amplifier, they will begin to move backward and forward. The backward movement represents a negative pressure, while the forward position represents the positive pressure the speakers make in the air particles in the car.

In that regard, polarity becomes important because the electrical current that is coming from the amplifier to the speakers should match the terminal.

The positive and negative terminals should match the amplifier’s positive and negative currents, or speakers would end up moving differently.

For example, even if the current sent to the speakers from the amplifier is positive, but you connected the wire to the negative terminal, the movement the speaker will be making will be backward even though the sound it produces is positive.

This could create weird distortions and changes in the quality of the sound coming from the speakers.

can incorrect polarity damage car speakers

How to tell if car speaker polarity is inversed?

There are a lot of cases where you might end up mixing the positive and negative wires with the positive and negative terminals if you are setting up your new car speakers because they don’t have labels or wires are not marked.

In case your car speakers don’t have marked terminals, it can be pretty difficult to tell whether or not your car speakers are polarity inverted.

In that regard, the best way for you to tell whether or not your car speakers’ polarity is not inversed is by making use of a speaker tester. 

Speaker tester is a tool that is specifically made for these cases and is not even very expensive. There are even speaker testers that generate their own signals so that they can be used for other purposes as well but the one I have been using is PAC TL-PTG2. It does not only test the wires but also checks if the speaker works properly.

Pac tester is available on Amazon, so if you are going to test either wires or speakers, click this link and check the latest price.

Using a speaker tester is quite easy, and you don’t need a ton of effort to know how to use one.

How to identify positive and negative speaker wires?

In most cases, you simply have to look at the labels on the speakers and the wires to know which ones are positive and which negative.

The plus and minus symbols will clearly indicate which ones are negative and which ones are positive. Meanwhile, in some cases, red color indicates positive, while a black color indicates negative.

But there are instances wherein they don’t have labels colors. That is why you must use a different method to learn which one is the positive wire and which one is the negative wire.

If you don’t have the budget to buy a speaker tester, you can use a 9V battery to test your speaker polarity instead.

Here is now you basically make use of one:

  • Place a speaker wire to the positive terminal of the battery. It doesn’t matter which wire you are placing on it.
  • After that, do the same with the negative terminal of the battery. Again, it doesn’t matter if you know whether or not you are using the positive or the negative wire.
  • Try to see how the speaker moves the moment you make the connection.
  • If the speaker moves forward or outward, you can assume that the speaker wire that is connected to the positive side of the battery is the positive wire.
  • However, if the speaker moves inward, it means the positive wire has been connected to your speaker’s negative terminal.
how to identify positive speaker wires

How did I manage to mess up the wiring?

If you noticed that you had indeed messed up the wiring when you tested for the speaker’s polarity by using a speaker tester or by making use of other effective methods, you don’t have to worry.

A lot of people make this mistake because it can be quite common, depending on the circumstances.

In a lot of situations, the most common reason for messing up the wiring can be due to a lack of information or even carelessness. Even if the wires and the speaker terminals are labeled and are colored, it can still be quite easy to mess things up, especially if you do not know how the labels work and what polarity means for your car speakers. 

As such, you might think that it’s okay if you connect the positive wire with the negative terminal and vice versa because you aren’t well-informed. That’s where informing yourself becomes important when it comes to car speakers.

There are also some cases where the car speaker wires and terminals are not labeled. When that happens, it can be pretty easy to make this mistake no matter how well-informed and experienced you are at setting up car speakers or other types of speakers.

What you have to do when it happens is to test the polarity and swap the terminals.

What happens if I reverse my car speaker wires?

Suppose you managed to reverse your car speaker wires and connected the positive wire with the negative terminal and the negative wire with the positive terminal. What happens to your car speakers then?

Well, for starters, the speaker polarity will be inverted in the sense that it will move forward when it is supposed to be moving backward and then vice versa.

This happens because the soundwaves and the pressure created by your speaker will be the opposite of the soundwaves that were recorded and then released by the amplifier to the speakers.

In short, inverse wiring will affect the way your speakers will function, and you may or may not even notice the difference in the produced sounds.

This is a case to case basis depending on the car speakers you have and on the type of music or sounds they are producing. But, generally speaking, the sound of your car speakers are affected if the polarity was accidentally inverted.

What kind of sound will my car speakers produce if I inverse the polarity?

In that regard, when you inverse the polarity of your car speakers, there will be some differences that are quite noticeable depending on the speakers and on the music you are playing.

It also depends on whether or not you are using multiple speakers because there will be instances wherein a one-speaker setup won’t show you a lot of changes in the sound quality if you inverse the polarity of your car speaker.

However, it can be on a case-to-case basis, and it is much more common if you are using multiple car speakers. In a setup where there are two speakers, and only one of them is out of phase, it is quite noticeable, and you can hear the left speaker plays differently from the right one.

Here are the common changes when you inverse the polarity of your car speakers:

No bass

The most common change that is quite easy to notice if you inverse your car speakers’ polarity is that there would be no, or very little bass produced.

That’s because the bass is primarily produced by the pressure created by the car speakers’ in and out movement. 

So, if the signals are crossed and your speakers are moving inward when the sound signal is supposed to make it move outward, the bass drum notes become very difficult to notice to the point that your speakers are not producing any bass at all. The music ends up losing the impact caused by the bass, and you won’t end up enjoying the quality.

Cancellation

Cancellation is a lot more common in a pair of bass speakers and won’t be as common if you only have one car speaker working. You can hear this quite noticeably when the car speakers are close to each other. 

When there is a cancellation, the speaker with an in-phase polarity actually cancels and competes with the speaker’s frequency that has an inversed polarity. It’s like you are clashing a negative number with a positive number of equal values—they both end up getting canceled.

The cancellation you hear can be noticed in the bass because of how the bass is produced. In effect, both of the speakers to cancel each other out.

This is much more common if the speakers are directly in front of each other. The cancellation effect is even more noticeable when you are in a smaller car where speakers are close to each other.

Poor imaging

In case you didn’t know what imaging is, it is when the car speakers can project an image of the instruments being played in the music.

So, if the car speakers are correctly wired, you will be able to more or less picture out the instruments in front of you as if you were actually watching the musicians live.

However, poor imaging happens when the speakers are not wired correctly or are out of phase.

You won’t be able to correctly process the information coming from the music to the point that you may not be able to picture out which instrument is making certain sounds. In other words, the sounds become vague, and your imaging gets distorted.

car incorrect polarity damage car speakers

Can incorrect polarity damage my car speakers?

Now that you know that incorrect polarity can indeed change the quality of the sounds created by your car speaker, you might be wondering if it will damage your car speakers in the long run. Especially when you consider the fact that your speakers will be moving in the opposite directions.

Well, while sound quality is indeed damaged and changed, you don’t have to worry about your equipment getting damaged if you accidentally inverse the polarity of your car speakers.

That is because the speakers’ voltage is generally the same regardless of whether the wires are positive or negative. In short, the electrical voltage isn’t changed even though the signals might be changed.

Still, you may end up having speakers that will not work acoustically well when they are correctly wired after having them incorrectly wired for a long time. That is why you always have to make sure that your speakers are correctly wired.

And suppose you noticed that they are not. In that case, you have to remedy the situation as quickly as possible to prevent any damage that can potentially happen to your equipment and your speakers’ sound quality.

Does polarity matter to car speakers?

With all that said, polarity does indeed matter to car speakers, especially when you are concerned with the sound quality they produce.

The polarity dictates the movement that your car speakers will be making, and if it is inverted, the movement is also inversed, so in effect, the sound will not be as good as you would expect it to be.

The changes that inverse polarity makes are much more noticeable when you only have one inversed speaker. It becomes less noticeable if all of your car speakers are inversed or only use one speaker.

However, to get the best sound quality possible, it is always recommended to check your speakers’ wiring and make sure that each wire is in the right terminal.

Martin

Welcome to ImproveCarAudio! I am Martin, and I love to write about everything related to car sound systems. I strive to provide the most accurate and helpful information about car audio through extensive research, as well as my experience with car audio installations.

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