Learning, Wiring,

How to Test Positive and Negative Speaker Wires with a  Multimeter? (2 Methods)

For those who have a hard time identifying positive and negative speaker wires correctly, this article will help.

Understanding a speaker wires polarity is far more important than one might think. It could come in handy while repairing or installing a sound system. So, here I’ll talk about how to test a speaker wires polarity with a digital multimeter.

In general, the most common way to check the polarity of the speaker wires with a multimeter is to:

  • Unplug all the other audio components.
  • Set the multimeter to DC volts settings.
  • Check the two speaker wires.
  • Reconnect the audio system.

Read the below guide to learn more about this and an additional method.

How to Use a Digital Multimeter to Determine the Polarity of the Speaker Wires?

A digital multimeter is the best way to confirm the polarity of speaker wires. In this method, you only have to check the multimeter reading, and here are the steps for that.

Things You’ll Need

  • Digital Multimeter
  • Two alligator clips

Step 1 – Unplug All Components

unplugging all the components of the speaker
Video | 4DIYers

First and foremost, unplug all the other audio equipment from the speaker unit. This should be done as a safety precaution, and it will keep your audio system safe.

But before you disconnect, remember to take a picture of the sound system and use it as a guide when you reassemble it.

Step 2 – Set up the Multimeter

setting up the multimeter
Video | 4DIYers

Then, set the multimeter to DC volts settings. To do that, turn the dial on to the VDC mark. Set the range to 200mV settings.

After that, connect the black colored jack to the COM port and the red jack to the VAΩ port.

Step 3 – Check the Speaker Wire

Now you can check the speaker wires. To do that, place the red and black leads of the multimeter on the two speaker wires.

Then check the multimeter reading.

checking the speaker wires with multimeter
Video | 4DIYers

The multimeter red probe is connected to the positive speaker wire if the reading is positive.

testing positive/negative wires with multimeter
Video | 4DIYers

The multimeter red probe is connected to the negative speaker wire if the reading is negative. You’ll get a better idea about it after inspecting the above images.

Tip: Use the alligator clips when you connect the speaker wires and multimeter probes.

Step 4 – Reconnect the Audio System

Finally, reconnect all the components of the audio system. Use the picture that you took at the beginning of this process.

This is the best method to correctly identify the speaker wires’ polarity. If you are looking for more methods, below you can find another two.


Method 1 – Use Color Codes

color codes for the cable
Video | ShowMeCables

If you have doubts about the wire polarity, checking the color codes is the easiest thing to do. The positive wire will be red, and the negative wire will be black. So you’ll be able to identify the positive and negative ends correctly.

However, these color codes won’t be available for every speaker wire. Sometimes, both wires might have the same color coding. Or sometimes there won’t be any color codes at all. If that is the case, make sure to check the user manual. And if it doesn’t work, follow the method below to identify the positive and negative speaker wires correctly.


Method 2 – Use a 9V Battery

This method is a bit more advanced than the first one, and you might get better results. You’ll need a 9V battery for this process, and here’s how you can use that battery.

Step 1 – Separate the Speaker

separate the speaker
Video | 4DIYers

First and foremost, separate the speaker from the other sound system components.

Important: In this method, you can check the speaker wires or the terminals. Either way, you’ll get a clear idea about the polarity of the speaker wires.

Step 2 – Connect the 9V Battery

connecting the 9V battery
Video | 4DIYers

After separating the speaker from other components, you are now ready to check the polarity of the speaker wires. For this demonstration, assume you are dealing with two speaker wires of the same color.

Connect the two wires to the two ends of the speaker and check the cone. If the cone is pushing out, the speaker wire polarity is correct. That means the positive speaker wire is connected to the positive battery end. And the negative speaker wire is connected to the negative battery end.

However, if the speaker cone pushes in, the polarity is incorrect. That means the positive speaker wire is connected to the negative battery end, and the negative speaker wire is connected to the positive battery end.

This is undoubtedly one of the best methods to check the polarity of the speaker wires.


What Should You Do After Identifying the Speaker Wires?

After identifying the positive and negative speaker wires, the first thing you should do is mark them. For instance, you might have two black speaker wires.

Mark one of them using electrical tape or a marker pen. That way, you won’t have to carry out the above testing process again and again.


Role of the Speaker Wires

If I finish this article without mentioning the role of the speaker wires, it wouldn’t feel right to me. So, here’s a simple explanation of the role of the speaker wires.

Speaker wires are responsible for connecting the speakers and amp. They maintain this connection by moving sound from the speaker to the amp. These speaker wires are usually made from copper, a good conductor of electricity.

Also, copper wires have a high resistance level to electrical noise. Because of that, copper is the perfect material for making speaker wires. You can get these wires in various lengths and sizes.


Importance of Knowing the Polarity of the Speaker Wires

The polarity of the speaker wires is directly related to identifying the negative and positive ends. But one might think the polarity of the speaker wires is not important. What difference does it make?

Well, if you think like that, too, you are wrong. The mixed polarity of the speaker wires can cause audio quality changes. So, to run your audio system properly, you must identify the positive and negative speaker wires. This audio quality drop can affect large sound systems remarkably.


FAQs

Can I Check the Polarity of the Positive Negative Speaker Wires Using a Multimeter?

Yes, you can check the polarity of the speaker wires with a digital multimeter. All you need to do is connect the two speaker wires to the multimeter probes. Then, check the reading. If the reading is positive, the polarity is correct. If the reading is negative, the polarity is incorrect.

Do Speaker Wires Have Voltage?

No, speaker wires don’t have voltage. Instead, they emit an electromagnetic field (EMF). If the wire quality and length are high, this EMF can cause headaches.

How to Identify Bad Speaker Wires?

Bad speaker wires can cause lots of issues for your sound system. When the speaker wires go bad, they tend to handle power poorly. This poor handling of the power can cause distortion. So, here are a few steps for checking bad speaker wires.

1. Strip one inch of the plastic coating from the speaker wires.
3. Check for continuity using a multimeter (you should check both wires together).
3. The speaker wires are bad if the multimeter doesn’t show continuity.



Video References

4DIYers

ShowMeCables

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About Sam Orlovsky

AvatarCertifications: B.E.E.
Education: University Of Denver - Electric Engineering
Lives In: Denver Colorado

Electrical engineering is my passion, and I’ve been in the industry for over 20 years. This gives me a unique ability to give you expert home improvement and DIY recommendations. I’m not only an electrician, but I also like machinery and anything to do with carpentry. One of my career paths started as a general handyman, so I also have a lot of experience with home improvement I love to share.

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