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How to Tell if Your Car Speaker Is Blown?

If you’re a car audio enthusiast, you know the importance of having quality speakers. But what happens when your speakers start to sound bad?

How can you tell if they’re just in need of a tune-up or if they’re actually blown? Let’s find out.

The simplest way is to listen to the speakers. If they sound crackly or distorted, chances are they’re damaged. Another way is to look at the cones, and if they are visibly damaged or torn, that’s a sign that they’re blown. Finally, measure the speakers’ resistance, and if it measures as infinite, the speakers are blown.

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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’s 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?

Distorted sounds are one of the most common signs of a blown speaker. This is because the physical damage prevents the speaker from moving as it should. As a result, the sound is no longer clear; instead, you’ll hear a lot of crackling or popping.

In some cases, the speaker might even emit a high-pitched squealing noise. Several things can cause this, but it’s usually due to a bad connection or loose wire.

how to know that car speakers are blown

If your speaker makes any of these noises, it’s likely blown and needs to be replaced.

Below are typical symptoms of blown car speakers:

  • They make distorted sounds, especially at higher levels.
  • Music is mixed with a crackling or popping sound.
  • You may not hear a full range of sounds. For example, bass tones have disappeared.
  • The speaker’s cone does not react to the signal from the amplifier, and it does not move.

As you can see, there are several points to look at, and if you experience any of them, it is worth removing the suspicious driver from the car and inspecting it properly.

Why Do Car Speakers Blow?

The most common cause for speakers to blow is thermal or mechanical failure.

#1. 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 coils are permanently damaged, bad speakers stop working altogether. Unfortunately, you cannot repair these damages in many cases, or even if possible, the repair costs can be high.

Another type of speaker damage due to excessive heat is the melting of the sensitive rubber or glue connecting the speaker’s cone with the suspension.

As a result, the cone separates from the suspension. If this happens, the partially blown-out speaker will stop playing, and all we will hear are the cracks coming from the loose voice coil with the suspension hitting the cone. When unnoticed, this can lead to a permanently damaged voice coil.

#2. The mechanical damages that cause a speaker to blow are mainly damaged cones or destroyed glue connections with either the speaker’s suspension or the surrounding ring.

Mechanical damages are caused by the voice coil’s extended movements inside 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 also risky to place speakers in too big boxes, or worse, allow them to play in the free air. This rule excludes free-air subwoofers, which are rare and not as sensitive to extensive cone vibrations as typical full-range or coaxial drivers.

The cone damages are easy to identify while performing a visual inspection of the entire speaker. Looking carefully at the surfaces, you will notice even the small tears on the speaker cone assembly.

However, regardless of the failure, you should pay attention to the correct installation of the whole car audio system.

Noteworthy is proper filter and crossovers adjustments to match 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 directly cause blowing out the speaker, mechanical and electrical damages affect them more often.

playing car speakers too loud

Remember that setting the volume too high when the speaker is weakened is just the trigger to blow it off.

Like any other engineering product, even the best speakers can be faulty, even as a brand new piece from the manufacturer. For example, they 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 damaging process, and it happens that even brand-new speakers blow within a fraction of a second.

However, if they are in good condition and the whole car audio system has been designed and installed correctly, volume as the only factor will not cause any damage. 

Is It Better to Overpower or Underpower Car Speakers?

Overpowering is generally 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 that 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 the 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, allowing them to use their full potential.

With higher power, speakers will play smoothly and without distorting high frequencies, which is exactly what we are looking for in an upgraded car audio system.

If you use an amplifier that is too strong for our 75W speaker, for example, 150W or more, and do not reduce its power on the gain knob, it can overheat the voice coil, which will lead to permanent damage.

This scenario is possible only when the amplifier significantly overpowers speakers while playing at full volume.

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 suspension.

At the most significant risk are subwoofers built into sealed boxes, with no natural airflow to cool the speaker, where the temperatures rise fast.

On the other hand, if you power the speaker with a weak amplifier or worse, a radio, this creates a higher probability for speakers to blow than from a more powerful amplifier.

Speakers that are not powered enough play quietly, and to make music louder, the only way is to increase volume. 

The music then becomes louder, and we may be happy. However, sounds are distorted because the amplifier cannot produce enough power for the demanding car’s speakers. As a result, the frequency response is reduced, sounds begin to be silenced, and you start to hear crackling.

how to avoid blowing car speakers

At this moment, you hear poor audio quality, which happens so often, and if you ignore these signs and continue listening to too loud music, the speaker will blow.

It is even worse when a weak amplifier cannot generate power for complete sound waves and begins to cut them off.

This effect is known as clipping and is deadly for an amplifier, and if the amplifier is equipped with the protection circuit, it will shut down.

In the worst case, though, the speaker blows to pieces due to a sudden, intense, and unstable electrical response.

Over the years, I saw many car audio systems composed of randomly selected speakers for which an amplifier was accidentally chosen.

It is worth paying attention to how strong the speakers are and how powerful the amplifier is. Otherwise, sooner or later, speakers in such systems can be destroyed.

How to Stop Car Speakers From Blowing?

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.

Turning the volume down is the most common recommendation to reduce the speaker’s probability of blowing.

However, as I mentioned earlier, 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 the top value.

This will allow you to still enjoy the music but for much longer. Well, you do not drive your car at the max. RPM either.

It is essential to match the speakers’ power with the amplifier. Therefore, the amplifier should have RMS per channel, at least matching the RMS of the speaker. However, as previously mentioned, 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, the first step is to set their frequency slightly higher than the manufacturer’s recommendations.

For example, when the speaker has been designed to work from 60 Hz, set a crossover at 70-80 Hz. You will not lose many bottom sounds, but the speakers will have a longer lifetime.

Conclusion

The best way to avoid blowing your speakers is by using a quality and well-matched amplifier. If you focus on these two factors, you will significantly reduce the probability of damaging the speakers.

It is also essential not to push the system to its limits by playing at maximum volume all the time, and it is also a good idea to use crossovers to protect our speakers.