Key Takeaways
- A subwoofer can be tested for damage using a multimeter.
- To test a subwoofer you need to remove it from the enclosure and attach the multimeter probes to the voice coil terminals.
- The resistance reading on the multimeter will indicate whether the subwoofer is blown or not.
- There are other ways to test a subwoofer including listening for distortion and checking the cone and voice coil.
Introduction
A subwoofer is an essential component of any audio system and it is responsible for producing low-frequency sounds. However like any other electronic device subwoofers can become damaged over time. One of the most common problems with subwoofers is that they can become blown which can cause distortion and other issues with sound quality.
In this article we will discuss how to check if a subwoofer is blown with a multimeter. We will also cover some alternative ways to test a subwoofer for damage.
Tools Needed
- Multimeter
- Screwdriver
- Tone generator
How to Check If a Subwoofer Is Blown With a Multimeter
To check if a subwoofer is blown with a multimeter you need to follow these steps:
- Turn off your subwoofer completely and unplug any power source.
- Remove all audio inputs or any cables to make your subwoofer free.
- Remove the subwoofer from the enclosure.
- Attach the positive multimeter probe to the positive terminal of the voice coil of your subwoofer.
- Connect the negative multimeter probe to the negative terminal of the voice coil.
- Turn on the multimeter and you will see the resistance.
- Evaluate your ohms to see if it is a blown subwoofer or not.
If the resistance reading on the multimeter is zero or very low it indicates that the subwoofer is blown. If the resistance reading is within the normal range it means that the subwoofer is not blown.
Normal Resistance Range for Subwoofers
| Subwoofer Size | Normal Resistance Range |
| 8 inches | 3.2 – 4.8 ohms |
| 10 inches | 2.5 – 4 ohms |
| 12 inches | 1.5 – 3 ohms |
| 15 inches | 1.2 – 2.5 ohms |
Alternative Ways to Test a Subwoofer
In addition to using a multimeter there are other ways to test a subwoofer for damage. Here are some alternative methods:
Listen for Distortion
One of the easiest ways to tell if a subwoofer is blown is to listen for distortion. If the sound coming from the subwoofer is distorted or scratchy it could be a sign that the subwoofer is damaged.
Check the Cone and Voice Coil
Another way to test a subwoofer is to check the cone and voice coil. If the cone is damaged or the voice coil is burnt it could be a sign that the subwoofer is blown.
Use a Tone Generator
A tone generator is a device that produces a specific frequency of sound. You can use a tone generator to test your subwoofer by playing a low-frequency tone and listening for any distortion or other issues.
Use a Subwoofer Tester
A subwoofer tester is a device that is specifically designed to test subwoofers. It can measure the impedance of the subwoofer and detect any issues with the voice coil or cone.
Troubleshooting Guide
| Problem | Possible Cause | Solution |
| No sound | Blown subwoofer | Replace subwoofer |
| No sound | Loose connection | Check connections |
| Distorted sound | Blown subwoofer | Replace subwoofer |
| Distorted sound | Incorrect settings | Adjust settings |
| Low volume | Incorrect settings | Adjust settings |
| Low volume | Blown subwoofer | Replace subwoofer |
- What are the different types of damage that commonly occur when a subwoofer is blown in a home theater?
When a subwoofer is blown it can be due to receiving too much power or too much of a distorted signal[1][2][3][6]. The following are the different types of damage that commonly occur when a subwoofer is blown in a home theater:
– **Poor sound quality**: One of the key signs of a blown sub is poor sound quality. If you notice any cracks in the sound it’s time to do an audio test. First reduce the sound to a low volume and commence audio playback. Increase the volume and bass slowly all the while paying extra attention to the sound. If it is distorted your subwoofer is partially blown and if there is no sound at all it is completely blown[3][5][6].
– **Distorted signals**: Subwoofers can easily be damaged by distorted signals. Subwoofers can be severely damaged by distortion or clipping in the signal. Until the levels become high enough to cause distortion and damage the signal can be distorted without you even being aware[6].
– **Blown coil**: A multimeter can be used to find out if the coil is blown. If the multimeter shows that the coil is blown it means that the subwoofer is damaged beyond repair[1].
– **Physical damage**: Subwoofers may be damaged by being dropped or by being hit by a physical item or by using too much force when checking the cone. A drop or physical blow to your subwoofer will often damage the cone[6].
– **Overpowering**: Overpowering is the most common mistake that damages a subwoofer. By overpowering you are given more power than is required to drive your subwoofer. If you increase the volume and bass past a certain extent for a long period you will end up with a blown speaker cone or subwoofer[2][6].
It is important to fully assess the woofer to determine the total amount of damage that has taken place when you suspect that a subwoofer in your home theater has been blown[1].
- How can you tell if a subwoofer has any damage to its electrical resistance using a multimeter? [5][4]
To determine if a subwoofer has any damage to its electrical resistance using a multimeter you can follow these steps:
1. Turn on the multimeter and set it to measure resistance. The multimeter’s dial should be turned to the Ohms position to measure resistance[1][4][5].
2. Connect the multimeter’s positive and negative probes to the voice coil’s positive and negative terminals respectively[6].
3. Read the multimeter’s display. The multimeter should display a resistance value that is within the subwoofer’s specified range. If the resistance value is outside of the specified range it indicates that there is damage to the subwoofer’s electrical resistance[1][4][5].
It is important to note that the specified range of resistance values can vary depending on the subwoofer’s make and model. Therefore it is recommended to check the subwoofer’s manual or manufacturer’s website for the specified range of resistance values[1][4][5].
- Once a multimeter confirms a subwoofer is blown what are the potential causes of the damage and what steps can be taken to prevent future subwoofer damage?
Once a multimeter confirms that a subwoofer is blown there are several potential causes of the damage and steps can be taken to prevent future subwoofer damage. The following are some of the potential causes of subwoofer damage:
– **Overpowering or underpowering**: One of the primary causes of subwoofer damage is incorrect power management. Overpowering a subwoofer by sending too much wattage can lead to overheating blown voice coils and other electrical failures. On the other hand underpowering a subwoofer can result in distorted audio as the amplifier may push the subwoofer to its limits causing clipping and damaging the speaker components[1][3].
– **Physical damage and mishandling**: Subwoofers are vulnerable to physical damage if mishandled or improperly installed. Rough handling dropping or impact can cause damage to the cone voice coil or other internal components. It is important to handle subwoofers with care during installation and transportation. Additionally ensure that the subwoofer is securely mounted or placed to prevent vibrations or movement that can potentially damage the speaker[3].
– **Environmental factors**: Environmental conditions can also impact the longevity and performance of a subwoofer. Exposure to extreme temperatures high humidity or direct sunlight can cause damage to the cone surroundings or other components over time. It is advisable to place subwoofers in a well-ventilated area away from direct exposure to the elements[3].
To prevent future subwoofer damage the following steps can be taken:
– **Proper power management**: Ensure that the subwoofer is receiving the correct amount of power. Overpowering or underpowering the subwoofer can cause damage. Check the subwoofer’s manual or manufacturer’s website for the recommended power range[1][3].
– **Proper handling and installation**: Handle the subwoofer with care during installation and transportation. Ensure that the subwoofer is securely mounted or placed to prevent vibrations or movement that can potentially damage the speaker[3].
– **Proper environmental conditions**: Place the subwoofer in a well-ventilated area away from direct exposure to the elements. Avoid exposing the subwoofer to extreme temperatures high humidity or direct sunlight[3].
By following these steps you can prevent future subwoofer damage and prolong the lifespan of your subwoofer.