How To Test Speaker Polarity And Does Speaker Polarity Matter? - Vita Audio

How To Test Speaker Polarity And Does Speaker Polarity Matter?

Speaker polarity refers to whether the left or right speaker is louder.

If you want to get the best sound quality from your speakers, you should test them to see which speaker has the stronger signal.

Speaker polarity matters because it affects the way audio signals travel through the air. The left speaker usually produces a weaker signal than the right speaker.

How To Test Speaker Polarity And Does Speaker Polarity Matter

This means that if you place the speakers too close together, they’ll cancel each other out.

To determine which speaker is louder, you can use a simple experiment.

Read on for a guide to that experiment, as well as everything else you might need to know about speaker polarity, including the answers to some of the most commonly asked questions regarding speaker polarity. 

What Is Speaker Polarity? 

Before we can get into the process of testing speaker polarity and whether speaker polarity matters, it’s important to know how it works.

The polarity of a speaker depends on the connection between the speaker and the amplifier. 

The positive speaker terminal for the speaker must be fully connected to the positive terminal for the amplifier.

Likewise, the negative terminal for the speaker must be fully connected to the negative terminal for the amplifier. If this connection is complete, then the speaker will be functioning with the right polarity. 

This is the case for the vast majority of audio equipment setups; usually, the red wire will connect to the positive terminal, and the black wire will connect to the negative terminal.

This isn’t always the case, though- sometimes they’re not colored at all, or if they are colored, the red wire is the negative wire and the black wire is the positive wire. 

Swapping the negative and positive connections will result in your speaker having reverse polarity. 

An Outline Of Speaker Polarity 

To understand the concept of speaker polarity in more detail, you need to have a basic understanding of sound waves, which are positive or negative changes in pressure.

These changes correlate directly with the speaker’s polarity. 

When the speaker polarity has been reversed, the pattern of the sound waves will be reversed; the positive periods turn to negative periods, and the negative periods turn to positive periods. 

It helps to think about the sound wave that would be created by an instrument like a drum.

When you hit a drum with a drumstick, the drumhead rapidly moves up and down, and this movement leads to both positive and negative changes to the surrounding air pressure. 

A downward motion (spurred by the downward stroke of a drumstick on the drum) will lead to a negative change in air pressure, meaning that if the drum were to be placed by a microphone, the initial section of the sound wave would be negative.

But if you reversed the polarity via the microphone’s connection, this part of the wave would instead be positive. 

How To Test Speaker Polarity 

If you want to test the polarity of a speaker, all you need to do is rest a 9-volt battery against the terminals of the speaker.

You’ll need to remove part of the protective coating on the wires so that the components within are slightly exposed. 

When the positive speaker terminal is touching the positive terminal of the battery, does the cone move out before it moves in?

Then your speaker’s functioning with the right polarity. You should also check the other speaker wire against the negative terminal of the battery, to see if the first movement is downwards. 

If the first movement of the cone is inwards when touching the negative wire, though (and if the first movement is outwards when touching the positive wire), then you’re going to want to swap your negative and positive wires and then try the test again. 

If you’re trying to test the speaker polarity and you miss the movement of the cone (which is very possible because said movement is extremely slight), then simply disconnect all the wires and start the process again. 

Having the wires connected to your speaker crossed is not an uncommon problem, especially when the wires aren’t labeled in regards to their polarity.

Quite often the positive wire will be connected to the negative terminal, and the negative wire will be connected to the positive terminal.

When this occurs, it means that the speaker is out of phase. This doesn’t always lead to issues, but you’ll likely pick up on some audible abnormalities.

These issues can usually be fixed by simply swapping the wires around, thus correcting the polarity of the speaker. 

What are some of the problems you might encounter when the wires are crossed, you might be asking?

The Most Common Issues Caused by Crossed Wires (Wrong Polarity)

There are several different problems you might experience when the wires between your speaker and your amplifier are the wrong way around. Here are all of the most common issues you’re likely to encounter.

It’s worth noting that while in some cases there will be no noticeable problems caused by crossed wires, there’s always the possibility that it will cause severe issues. 

Zero Bass Response

When the audio equipment you’re using is out of phase (because the wires are crossed), almost always there’s going to be a reduced bass response. 

The reason for this issue stems from the fact that lower frequencies depend on the pressurization surrounding the speaker to get anywhere.

When the cone is moving in before it’s moving out, the impact of softer tones is ultimately lost. 

Cancellation Of Audio 

If two speakers are both set up within the same area, the speaker that’s out of phase because its wires are crossed will be competing for the same frequencies as the speaker that’s not out of phase. 

When this occurs, the music will still be sending information, but due to the sound waves canceling each other out, the bass won’t be audible. 

Vague Highs 

Vague highs occur because the higher frequencies become more esoteric due to incorrect polarity.

This essentially means that the focus on higher frequencies is lost, and they become airy. The effect is much the same as if you’d expanded the space in which the audio is being played.

The performance of each driver will be affected by the incorrect polarity, leading to a far thinner sound. 

The Impact On Audio Imaging 

Audio imaging is essentially when a pair of speakers can project an audible and accurate representation of an instrument. The wrong polarity can lead to sonic disorganization. 

Tips For Testing Speaker Polarity 

You’re unlikely to notice problems caused by the wrong polarity if your speakers are all connected via the same wires.

Nonetheless, the general rule of thumb is that each speaker should be wired to your amplifier separately. It might take a little more time to wire them this way, but your audio will benefit from increased accuracy. 

Knowing which wires go where is a far simpler process when the wires are either labeled or are specific colors that correspond to positive and negative.

For example, red wires tend to be positive, and black wires tend to be negative- that’s the standard across the majority of audio equipment setups. 

In other cases, one of the wires will have a stripe on it to indicate that it’s either positive or negative (usually a striped wire is a negative wire).

Sometimes it’s not a case of different colors, but instead, one wire is smooth and the other has small bumps or ridges on it. 

If the wires you’re working with aren’t labeled and they’re both the same color (and there are no other noticeable differences between them), you could always label the wires yourself so that you won’t be crossing the wires in the future. 

It’s also possible that the wires are labeled, but you’re unable to see these indicators because they’re running through a wall or contained by a conduit.

If this is the case, you’re going to need to test both connections to find out which will result in the correct polarity.

Other Ways To Test Speaker Polarity 

While the most common method used for determining the polarity of one or more speakers is by using a 9-volt battery, there are a few other ways you can test this, including the multimeter method, smartphone apps, and tools designed specifically for testing speaker polarity. 

Using A Multimeter 

Using A Multimeter 

You can also use a multimeter (if you have access to one) to determine the ohms (a unit of energy measurement) of your speaker.

All you’ll need to do is set the multimeter to its lowest range.

The multimeter will act as a current source, and if the multimeter is set low enough, you’ll see the same movement you would see if you were using a 9-volt battery. 

This process will require you to compare both speakers (or more than two speakers, if you’re using that many) to determine whether or not there’s going to be a polarity problem when you’re trying to use the equipment.

If you only have one speaker, you’re not going to get much indication of the ohms. 

The multimeter method is unlikely to be successful if your speaker is a piezoelectric one. This can be because of one of two reasons.

In some cases, the battery won’t be powerful enough for you to receive the correct reading. In other cases, though, the product might be enclosed, meaning that you won’t be able to see which way the cone is moving. 

The best multimeters on the market tend to measure as much as 1000V AC/DC.

If you’re looking to acquire a multimeter, you should be keeping an eye out for a safety rating of as much as either CAT IV 600V or CAT III 1000V. 

Tools Designed For Measuring Speaker Polarity

There are multiple different tools available that will allow you to test the polarity of one or more speakers without the need for a 9-volt battery or a multimeter.

You can easily find a Speaker Polarity Tester online, or a Tone Generator tool. Both of these can test speaker polarity. 

These tools tend to work with a 9-volt popper that allows you to test the movement of the speaker’s cone, and you can connect it to the unit with either RCA or with alligator clips.

All you need to do to test the polarity of a speaker is connect it to the testing tool and then turn the speaker on.

Smartphone Applications 

If the speakers and amplifiers are already connected and a signal can be passed from your input through to your output, one way to test the polarity of your speakers is via a smartphone app, of which there are plenty.

You should be able to pick up a free (or, at most, very affordable) app on both the iOS App Store and the Google Play store.

Look for an app that can connect your phone’s output to the input of your speaker, because once you’ve connected them, all you need to do is move the microphone of your phone near to your speaker.

The application works by sending a positive impulse into your speaker, allowing you to check the polarity. Depending on how the cone moves during this test, you’ll be able to decide whether some rewiring is required to correct the polarity. 

Frequently Asked Questions

Here are the answers to some of the most commonly asked questions on the topic of speaker polarity.

Can Reverse Polarity Damage Speakers Or Amplifiers? 

Luckily, crossing the negative wire and the positive wire does not result in actual damage to either the speaker or the amplifier.

Still, the potential consequences of reverse polarity are far from ideal, especially if you’re, say, performing live music in front of a crowd. 

Needless to say, you should always make sure that the connection is correct, even if this means you have to label the wires yourself.  

Is Polarity Important For Car Speakers?

So, what about the polarity of the speakers in your car? This is also something to be aware of, although you might have never considered it. 

The reason polarity matters here too is because if the speakers in a car are connected incorrectly, then just like with traditional speakers the sound is going to be out of phase.

This will mean that the track you’re playing through your car will be manipulated into playing a mono sound. 

Reverse polarity interferes with the stereo image, as well as the sound of the bass.

If it appears that your speakers have been wired incorrectly, then you’re going to need to find a way to switch them to the correct configuration.

Most mechanics will know what to do, though, so it’s usually not something to be worried about. 

Determining whether the polarity of your car’s speakers is inverted can be tricky, though.

Your best bet (although you could just go to an expert) is using one of the aforementioned speaker testers. These tend to be very affordable and work by generating a signal through the speaker to test the polarity.

As well as this, they’ll also check that every other component of the speaker is working correctly too. 


While it can sometimes be hard to even notice the problems that reverse polarity can cause, these problems can often be severe.

They’re not going to damage your speaker or your amplifier, but you’ll want to remedy them as soon as possible, otherwise, the quality of your audio will be far worse. 

So, yes, speaker polarity matters immensely.

The simplest way to find out whether your speaker is functioning with the correct polarity is by checking that the positive wire is connected to the positive terminal of the speaker, and vice versa. 

If the wires do not indicate whether they’re positive or negative, though, then you’re going to need either a 9-volt battery, a speaker polarity tester, or a smartphone application.

If you enjoyed this article, you might enjoy our post on ‘Sonos One Gen 1 vs Gen 2: Key Points [Guide]‘.

Jacob Stable
Latest posts by Jacob Stable (see all)