By Brian Casey
In a car audio system, the most delicate component is the speaker. They are the most important parts of the audio system and the most annoying when they get blown. Knowing how to test car speakers is one important thing for any person willing to take matters on her hand without spending a dime on a car mechanic.
Sometimes the problem might really appear to be with the speakers, but it might be the speaker connections or the even the amplifier. Before doing any test on your speakers, you will need to be sure of how to go about it.
That is why knowing how to run tests on the speaker wires, the amplifier fuse and capacitors is important.
Related article: Best JBL Car Speakers
Testing The Speaker Wires
Before you can test the speakers, it is always advisable to test the wires for continuity so that you can clear the air and proceed to testing the speakers. Sometimes speaker wires get cut or become frayed when they have moved around.
Under such conditions, the speaker wires become hard to spot where they are cut with a naked eye. So how can you accurately test the speaker wires? Here is a quick way;
1- Find the tools
Tools used when testing speaker wires are mainly a digital multimeter or an analog voltmeter.
2- Switch off all the components
This is always the first step in any diagnosis process. Turn off all the components of your stereo system. This will ensure that you do not by any chance create a short which may in return damage the whole system.
3- Disconnect the speaker wires
The third step will be to disconnect the speaker wires from the speaker box. There are two ways to that you can do this depending on the speaker or car model. One is pressing the positive and negative clips to disconnect the wires and secondly twisting two connectors counterclockwise to release the wires.
4- Disconnect from the stereo
The fourth step will be to disconnect the wires from the stereo receiver or the amplifier. This step will mainly involve removing the wires from the rear of the receiver or the amplifier. You will need to be careful when disengaging the wires from the mechanical locking mechanism. Disconnecting the wires here may involve pressing down a clip or twisting two wire caps.
5- Create a closed circuit using the wires
After successfully removing the wires from the speakers and the receiver or the amplifier, you will need to make a closed circuit so that you can perform a continuity test. To create this circuit, secure the end of the wires by carefully and tightly twisting them together. Be careful not to twist them too much as they might pose some difficulty when separating them later.
6- Set the voltmeter
With the circuit ready, you will need to prepare the voltmeter too. Switch it on and then select the ohms setting for measuring the wire resistance by setting the selector to the ohms position. If you are using a digital multimeter, this stage won’t be necessary.
7- Calibrate the Voltmeter
Before you can proceed to test the wires, you will need to determine whether the voltmeter is faulty or accurate. To find out, bring the red and black leads together. If the voltmeter displays a reading of 0 ohms, it means that the voltmeter is accurately calibrated.
If the voltmeter displays any other readings, it means that it not accurate and you will need to find a replacement. Ensuring that the voltmeter is accurate plays a great role in eliminating misguiding results. The same applies to a digital multimeter.
8- Test the speaker wires
Now with your accurate voltmeter, touch the red and black probes on the open end of the circuit. That is the end of the two wires that are not twisted together. For uncut or undamaged speaker wires, the voltmeter should display some resistance while for damaged speaker wires the voltmeter should display infinite resistance.
For a digital multimeter, if the wires are uncut or unbroken, the meter will produce a continuous tone, and on the LCD, it will NOT display “OL” (Open).
Analysis of these results would be; infinite resistance means that there is a space along the length of the wire. And from Physics, air has infinite resistance while for a continuous wire, the voltmeter will be able to measure the resistance of the wire and hence a small reading.
It will be important to note that amplifiers affect the sound that is heard from the speakers. Usually, if the amplifier has a problem, distortion will be heard through the speakers. If care is not taken, this problem might be misunderstood to mean the speakers are blown.
For more information: How To Turn Car Speakers Into Home Speakers
So, how do you know that the amplifier is blown? Amplifier problems result from the amplifier’s fuse or capacitor. Here is how to test an amplifier fuse and capacitor for fault;
1- Testing the Fuse
To access the fuse location, open the fuse box. Check the location on your car’s manual to find the location of the fuse box of your car. This location varies in various car models. After locating the fuse box, set the multimeter to the conductivity test. Touch the multimeter red lead to one of the fuse poles and the black lead to the other.
If you hear a beeping sound, the fuse is functioning. If not then the problem might be with the capacitor.
2- Testing the Capacitor
To test the capacitors, you will need a digital multimeter with an option of testing capacitance. With the meter ready, here is a quick way to test the capacitors.
Attach the negative and positive leads of the meter to the corresponding negative and positive terminals of the capacitor. If the capacitor is working correctly, then the meter will display readings that are almost the same as the ratings of the capacitor.
Testing the speakers
Now that you are certain of the speaker wire connections, fuse and the capacitor, it will be the time to test the speakers. Testing for faults in speakers or if whether the speakers are blown or not will involve some few options. You can also watch this video for more on how test car speakers.
1- Option 1: Listen
This is more of a diagnostic process. Faultiness in speakers can be found by carefully listening at appropriate volumes. This will, however, require a keen ear like that of a person who loves listening to music so much. Adjust the bass and treble levels to twelve o’clock position.
Carefully listen, if you spot that there is lack of range; it might mean that the speakers are not well properly equalized. The second thing to do is listening for distortion. To recognize distortion, play a track using your headphones or your home stereo, ensure that the track is free of scratches.
Play the same track on your car’s speakers; listen for rattling or crackling noises. If the speakers muffle, then it means that one of the speakers is blown. You can always try to isolate the speakers to the find which one is blown. To isolate the speakers, use the panning or fading function. By doing so, you are becoming specific to which speaker the problem might be.
2- Option 2: Inspecting the speakers
Another way to test if the speakers are working is to inspect. Inspecting means you will use your naked eye to try to find out if they are working. Here, however, you will be helped by a 9-volt battery. After removing the speaker from the speaker box, connect the speaker wires to the 9-volt battery and see if the speaker cone moves. If it moves then the speaker is working, if not it will be time to inspect for damage.
3- Option 3: Use a multimeter
Another way of finding if the speakers are working is using a multimeter. Connect the multimeter leads to the speaker terminals. Positive or the red lead to the positive terminal and the negative or the black to the negative terminal. If the multimeter displays a reading of 1.0 ohms, it means the speakers are working. If it displays infinite resistance, it means that the speakers are blown.
After testing your speakers and finding out what the problem is, you can always try to find out if the problem can be solved or if it will be time to replace the speakers. Inspecting the speaker for damages will be wise. Distortion always results from holes, splits or tears on the speaker. Run your hand along the soft cone to look for scraps.
If you spot any minor damage that can be repaired, then you can use a special seal for sealing speaker cones. If the damage is big, it will be worth taking it to a technician and finding out if the speaker is still repairable. That marks our final words on this article. We hope you now have some rough idea on how to test car speakers and your car system as a whole.