Car speakers can have lower performance over time due to wear and tear, but when it comes to a sudden drop in quality, this is often due to a blown speaker.
Blown car speakers are not always easy to spot and can sometimes be subtle, so it’s important to know the signs of a blown speaker.
There are several ways to tell if your car speakers are blown.
- Distorted sound, hissing, and fuzziness.
- The sound may also be muffled or tinny.
- Pops and cracks.
- Lack of certain frequencies, either bass, middle or high tones.
- Visible damage or lack of vibrations.
- Speakers have high or infinite impedance.
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Tip: If the speaker does not perform, the easiest way to find out of it is blown is to check the impedance using a multimeter (link to Amazon).
Car speakers in good condition have impedance depending on type between 2 and 4 ohms (some subwoofers can have 1ohm impedance).
If your speaker has exceptionally high or infinite impedance, it is blown.
In the article below, you will find more information about blown car speakers and how to protect them from this issue.
What does a blown car speaker sound like?
If you are wondering if the blown speaker makes any sound, it depends on the level of damage and which part of the speaker does not work. When the speaker is blown, it either does not work correctly, or it does not work at all.
Below are typical symptoms of blown car speakers:
- Speaker make distorted sounds, especially on the higher volume
- Music is mixed with popping, crackling
- Speaker does not play partial frequencies, for example, bass disappeared
- The blown speaker does not react on the signal from the amplifier, and the cone does not vibrate.
As you can see, there are several points to look at, and if you experience any of them, it is worth removing the suspicious speaker from the car and inspecting it properly.
What causes car speakers to blow out?
Two main causes for speakers to blow are mechanical and thermal failures.
Thermal damages are the most dangerous for the speakers because when the speaker receives too much power, its voice coil may overheat, and as an effect, the thin wire can melt or burn due to high temperature.
When the voice coil is permanently damaged, the speaker stops working completely. In many cases, these damages cannot be repaired, or if repair is possible, it is expensive.
Another type of speaker damage due to excessive heat is the melting of the sensitive rubber or glue connecting the cone with speaker suspension. As a result, the cone separates from the suspension. If this happens, the speaker will stop playing, and all we will hear are the cracks coming from the voice coil with suspension hitting the cone. When unnoticed, this can lead to blowing of the voice coil.
The mechanical damages that cause a speaker to blow are mainly damaged cones or destroyed cone connections with either suspension of the speaker or its surrounding.
Mechanical damages are caused by the extended movements of the voice coil inside of the magnet. The voice coil, which moves too far up and down forces the cone and other parts of the speaker to overstress and, as a result, the weakest material breaks.
It is very risky to place speakers in boxes that are too big, or worse, allowing car speakers to play in the free air.
Regardless of the failure, we should pay attention to the correct installation of the car audio system. Noteworthy is proper filter adjustments on the crossovers and matching the amplifier’s power with the speakers.
Can you damage speakers by playing them too loud?
Although turning the volume too high in the car and listening to loud music for a long time can be a direct cause of blowing out the speaker, there are other causes that directly affect the speaker’s performance. These are mechanical or electrical damages.
When the speaker is already weakened, setting volume too high is just the trigger to blow it off.
Like any other engineering product, speakers can be faulty even as a brand new piece from the manufacturer. Car speakers can have weak cone gluing with the surrounding and suspension, or their voice coils misalign with the magnet.
In such cases, high volume speeds up the speaker’s damaging process, and sometimes brand new car speakers can blow within a fraction of the second.
However, if your speakers are in good condition and the whole car audio system has been designed and installed correctly, volume as the only factor will not cause a speaker to blow.
Is it better to overpower or underpower car speakers?
In general, overpowering is less dangerous for car speakers than underpowering them from the weak amplifier or head unit.
Each speaker is designed to work with specific and stable RMS power, but many manufacturers specify the range of RMS speakers should be powered with, for example, from 20W to 80W. Such variety is only the indicator of the recommended amplifier. However, the best practice is to have an amplifier that exceeds speakers’ RMS by up to 50%.
For example, if you have speakers with 75W RMS, the amplifier should ideally have about 100 to 110W RMS per channel. In this case, we will be able to use speakers’ full potential. They will play smoothly and without distorting high frequencies, which is exactly what we are looking for when buying new speakers.
If we use an amplifier that is too strong for our 75W speaker, for example, 150W or more, and do not reduce its power on the main switch, we can overheat the voice coil, which will lead to permanent speaker damage.
This scenario is possible only when the amplifier significantly overpowers speakers, and also we listen to loud music. Voice coil can be damaged due to the high temperature, and even if it does not burn, it may cause other speaker components to melt, for example, glue or rubber connection with the speaker’s suspension.
At the biggest risk are subwoofers built-in closed enclosures, where there is no natural airflow to cool the speaker, and temperatures rise fast.
On the other hand, if we power our speaker with a weak amplifier or use a radio, we create a higher probability for speakers to blow than when we use a more powerful amplifier.
Speakers that are not powered enough play quietly, and to make music louder, we are increasing volume often to the maximum without understanding what is happening with speakers.
The music becomes louder, and we may be happy. However, sounds are distorted, because the amplifier is unable to produce enough power for the demanding speakers. As a result, speakers start to cut the frequencies, sounds begin to be muffled, and we are starting to hear crackling.
Generally speaking, we hear everything but not quality sounds, and this is happening so often. If we ignore these signs and continue listening to too loud music, the speaker will blow.
It is even worse when a weak amplifier is unable to generate power for full sound waves and begins to cut them off. This effect is known as clipping. Clipping amplifier is deadly for the speaker, and it often happens that the speaker blows to pieces due to sudden, intense, and unstable electrical impulses.
Over the years, I saw many car audio systems composed of randomly selected speakers, for which amplifier was accidentally chosen. It is worth paying attention to how strong the speakers are and how powerful is the amplifier. Otherwise, sooner or later, speakers in such systems will blow.
Can I avoid blowing out car speakers?
Repairing or replacing blown speakers can be not only costly but also will create unnecessary work. It is, therefore, better to avoid blowing out speakers than replacing them.
The most common recommendation to reduce the probability of speaker to blow is turning the volume down. However, as we said earlier in the article, volume alone will not destroy the speaker, nevertheless playing nonstop at 100% will not help speakers’ lifetime.
If we like loud music, we can set the volume very high, but do not go to the maximum. It will not make a significant difference when we play at 90% of the volume, or -6 dB below top value. This will allow us to enjoy our speakers for much longer. We do not drive our cars at maximum RPM either.
It is essential is to match the power of the speakers with the amplifier. The amplifier should have RMS per channel, at least matching RMS of the speaker. However, it is recommended to use a stronger amplifier, up to 50% more than speakers.
Another point is related to the crossovers or filters in the amplifier. When using crossovers, we should set their frequency higher than manufacturer recommendations. For example, when our speaker has been designed to work from 60 Hz, we should set a crossover at 80 Hz.