How To Test A Subwoofer? - Steps-By-Steps

Your subwoofer is not working, and you are confused if it’s blown or some other issues. After performing the tests I am going to tell you, you will be able to tell what is exactly wrong with your subwoofer.

Let’s go.

Testing The Amplifier

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Firstly you need to figure out is there any problem with your amplifier or your subwoofer itself?

Well, You can quickly figure it out by testing the amplifier. While performing this test, keep in mind that all power source and ground wires are correctly connected, and resistance should be equal on both sides of the amplifier.

If you get a reading on the meter, then most likely, your amplifier is fine.

If you get no reading or superficial reading, then most likely, your amplifier has blown

Testing The Subwoofer Without An Amplifier

Here are some simple steps to test subwoofer without an amplifier:

  1. First, turn off the car and your amplifier.
  2. Open the bonnet of your car; there should be a bolt between the battery and chassis that holds the ground wire to the chassis. Remove this bolt.

Now you will test your subwoofer by shorting all the terminals using a small piece of cables or wires.

Connect one side of the wire to each terminal which is on the subwoofer.

You don’t need your amplifier in this case.

  1. Now, start your car and turn on your music; if you hear a thumping bass, it indicates that one of the terminals has a problem. Most probably, it’s blown.

However, if there is no sound or you don’t hear anything, that means your subwoofer is not working at all.

Testing The Subwoofer With A Multimeter

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This is the most critical step since you want to know whether your subwoofer speaker is blown or not. If you have a multimeter, this test will be very easy for you.

  1. First of all, you need to turn off your amplifier.
  2. Remove the power source wire that is going to the amp to isolate it.
  3. Now, connect one side of your multimeter positive(+) probe to the positive terminal of the subwoofer and another side to the ground. (Do not touch any exposed wires)
  4. Now turn on your car and music; if you get less than 4 ohms, that means you have a blown subwoofer. If you get higher than or around 4ohms, it means your subwoofer is good. Check the next step for further diagnosis.
  5. Turning off your car and turning on the music will remove any components that might interfere with the reading. This way, you’ll get accurate readings

Testing A Subwoofer With SpeakON Output

If your amplifier uses speakON connectors instead of standard speaker wire terminals, it is very helpful to know how this connection works.

Most of the speaker cables that you will use in-car audio are 4-ohm cables, and using this cable; you can test subwoofer easily.

You need to test subwoofer in the following way:

  • First, turn off your amplifier and connect one side of the positive multimeter probe to a negative speakON cable.
  • Then, connect another side to the metal base of each speaker connector.
  • You should get readings around 4 ohms.
  • If you get double the reading on your multimeter, that means it is shorted, and if you get an open circuit or meagre resistance, then the speakON connector has blown.

Remember that this test should be performed with a 4-ohm cable because other cables might not work properly.

So, this is how you test a subwoofer with a speakON cable; I hope it will help you.

What To Do If Your Subwoofer Has Blown?

How To Test A Subwoofer? by

If you have followed all the above steps and your subwoofer is still not working, it is most likely dead.

In that condition, there is no option but to change your subwoofer. You can replace it with a new one or try to fix it by changing a few parts.

In case of replacement, you need to buy a new subwoofer with the same RMS(Root Mean Square) wattage and the same ohm rating.

Benefits Of Testing The Subwoofer

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  1. Ability to know if the subwoofer is blown or not.
  2. Helps you to change a new subwoofer instead of wasting money on useless repairs.
  3. It Gives you knowledge about how the speakON connection works and saves you from visiting your local car audio guy every time.
  4. Helps you to diagnose the problem of blown speakON connector on your amplifier.

Why We Need Of Testing The Subwoofer

Having a better subwoofer in your car is like having an extra pair of speakers because the woofer do the main work, and we all know how important it is to have a clear sound quality.

So if you have blown your subwoofer, then there are two options:

  1. Doing some repairs on it.
  2. Buying a new one.

Usually, people, especially car audio guys, spend so much time trying to fix it, which wastes both time and money.

Hopefully, this article gives you enough information to test a subwoofer and know if it is blown or not.


Q: Why Is My Subwoofer Not Working?

A: There are few possible reasons for this. You can check it by performing the above tests or asking some local car audio inputs guy to help you.

Q: How Do I Test A Subwoofer With 4-Ohm Cables?

A: Technically, there is nothing complicated about testing a subwoofer with 4-ohm cables. You should check the manual of your amplifier to see how it works. Still, you need to connect one side of the positive multimeter probe to the negative terminal cable and the other side to each speakON connector on the amplifier.

Q: What Is A Good Ohm Rating For My Subwoofer?

A: The ohm rating depends on the power of the subwoofer and the amplifier. Generally, most car audio subwoofers range from 1ohm to 2ohms on average, but if you have a powerful amplifier, it is not needed to be that low.

Q: How Much RMS Wattage Should I Buy?

A: Many factors affect the RMS wattage rating. Such as the size of the subwoofer, the number of speakers in your car and the type of amplifier. Generally, most car audio subwoofers range from 200watts to 1200 watts on average, but if you have a powerful amplifier, then there is no need to be that much. For example, if you have a 600-watt amplifier, buying a 300 watts subwoofer should be enough for your car.

Q: Can I Use 4-Ohm Cables To Test The Voice Coil Resistance Of My Speaker?

A: Yes, This is another way of checking the faulty speaker. You can check the resistance by voice coil terminals using a multimeter or the resistance box of your car audio amplifier.