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Why Do Car Speakers Blow?

Like any other electrical elements, also car speakers can get damaged, and one of those damages you probably came across was that the speaker has blown.

But what does it mean that the speaker has blown, and why do car speakers blow? Let’s find out.

Car speakers can blow for several reasons. 

#1. Overdriving the speaker (playing music too loud or for too long) 

#2. An imbalanced amplifier (which may be overworking one speaker or channel more than the other) 

#3. Wiring that is not of good quality.

#4. Poorly designed speakers.

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Tip: If your car speakers are blown, consider replacing them as soon as possible because the blown speaker produces poor sound quality and may even cause damage to other speakers.

The best way to find a bad speaker is to use a multimeter (link to Amazon) and check the resistance between both speaker terminals.

If the reading says zero or has massive resistance, the speaker is blown.

In the article below, I will go into more detail about some common reasons car speakers blow and how to prevent it. I will also provide some tips on how to protect speakers from blowing.

Why do speakers blow?

When a car speaker has been damaged, we can hear people saying that the speaker has blown. But what exactly is a blown speaker, and what causes it?

If the speaker has blown, it either has stopped working entirely or its sounds which used to be good, suddenly deteriorate.

The main reasons for speakers to blow is either thermal or mechanical failure, which prevents the speaker from working correctly.

why do car speakers blow

Mechanical failure usually occurs when the speaker’s cone movements are more extensive than they should be, while thermal failures happen when internal parts of the speaker burn or melt due to being overpowered by the amplifier.

In addition to the above, speakers can blow when you listen for a long time to music that is too loud or when they are old and internal parts are not as strong as in new speakers.

This happens most often to factory car speakers made from low-quality materials.

Below are the most common causes of blown-out car speakers:

#1. Overpowering car speakers

In speakers that receive too much power, the voice coil will force the speaker cone to excessive moves, which is especially dangerous at low frequencies where the cone’s movement amplitude is largest.

When the cone vibrates and moves too far, it causes stress on the cone’s connection with the suspension and surroundings.

As an effect, the weakest material will tear or break if forces are too high.

Most damage happens to the weakest paper cones, causing music distortion and crackling sounds from the speaker.

In extreme cases, when the cone’s connection with either suspension or surroundings has been damaged, the speaker stops working. 

#2. Clipping amplifier

Clipping is caused by a weak amplifier that the powerful speakers force it to deliver more power, which can severely impact the speaker.

The problem with a clipping amplifier is that it doesn’t produce regular sound waves.

Instead of producing a smooth waveform, it makes flat peaks and valleys, increasing the power sent to the speaker’s voice coil.

When this happens, the voice coil will heat up and eventually burn, causing the speaker to blow.

For example, if you have 300W RMS speakers and a head unit or small 50W amplifier powers them, you often do not hear the music’s expected dynamic.

As an effect, you turn the volume up to the maximum. This, however, does not help.

You start hearing distorted sounds because the speakers are begging for more electricity, but the amplifier cannot supply more.

If this happens and the amplifier is too small, you hear loud but mediocre music quality with distorted sounds, or in the worst case, the speaker blows right away.

The large, unstable voice coil vibrations will destroy the speaker’s weakest part.

blown car speaker

#3. Volume set too high

This is similar to the previous point but with equal amps and speakers’ power.

Listening to loud music creates a large energy supply to the speaker, which is the biggest mistake in many amateur car audio systems.

If the speaker receives more electricity than it can handle, this can cause overheating thin voice coil wire.

An overheated voice coil can either burn or lead to melting other sensitive speakers’ elements, for example, the glue that connects the speaker’s suspension with the cone.

This can happen in systems with amplifiers overpowering weak speakers because their gain is set way too high.

More dangerous for the speakers are playing them too loud when the amplifier is not powerful enough to power the speakers.

#4. Incorrectly set crossover’s pass filters.

Wrong or incorrectly set crossovers also cause speaker damage. Significantly affected are tweeters, which receive too low frequencies for them.

When the tweeter tries to play low frequencies, vibrations of the sensitive cone are way too high, which causes the cone to delaminate, and causes permanent speaker damage. 

#5. Speaker is mounted into a large enclosure.

The speaker enclosure’s wrong size is another common cause of blowing the speaker, and this does not apply only to the subwoofers but also to the speakers installed in car doors.

Enclosures too large do not create required pressure; as an effect, significant and unstable cone movements can damage the speaker’s surroundings. The same can happen to door speakers with ample open space behind the magnets when you listen to loud music.

When you build a bass box for your car, remember to follow a recommendation from the speaker’s manufacturer regarding the box volume.

It is always better for the speaker when the enclosure is smaller than too large.

However, do not go to the extreme. When your enclosure is way too small for a particular speaker, the voice coil may overheat because of the cone’s limited movements caused by the high air pressure in the box, and the speaker sounds flat and muffled.

How do I tell my speaker is blown?

It can be challenging to tell immediately if car speakers are blown when they make strange noises or do not react to the signal.

If you are wondering what a blown car speaker sounds like, it depends on the speaker and the type of damage.

Any damage that causes the speaker to rattle, make sound blurred, or create strange noises, can result in a blown speaker. But how do we check if a speaker is blown?

Below are common signs of blown car speakers:

The speaker plays music, but the sounds are distorted.

If you hear such weird noises, it may mean that one of your speakers is damaged. Try to reduce the volume and listen carefully to the sound quality.

It is essential to listen to high-quality music, preferably from a CD, because mp3 or other file types are often highly compressed and do not offer the highest sound quality.

If you hear that sound quality gets worse aligned with increased volume, you must locate the bad speaker using the fader and balance functions in your head unit.

In most cases, you will find a partially blown speaker with a loose or damaged voice coil.

What does a blown speaker sound like?

When a speaker is blown, it will not reproduce the sound accurately and produce fuzzy, low-quality audio. You might also hear rattling noises or distorted sounds coming from your speakers.

At higher volumes, you may notice that some frequencies are louder than others or have a chaotic, tinny resonance.

#1. Music sounds are mixed with popping, rattling, or buzzing sounds.

Hearing these types of noises and music signifies severe speaker damage.

Although crackling may be caused by damaged or loose wires, to make sure what causes the issue, you have to find the troublemaker.

If the cables are okay and the speaker still makes such noises, it will likely be blown.

To double-check whether the wire or speaker caused the problem, the easiest way is to swap the left speaker with the right one.

how to protect car speakers from blowing

If you hear the same speaker making weird sounds when connected to the other side, you have a blown speaker.

However, if you hear crackling coming from the same place but from a swapped speaker, you have to check the wire because your speaker is good.

#2. We hear only partial tones.

When you hear the music, but some tones are missing, for example, the only sounds you hear are bass or only treble, your speaker can be partially blown.

Try to balance different tones on the equalizer, and if you do not hear a full range of sounds but used to play well, prepare yourself for its repair or replacement.

#3. No response from the speakers to the signal

This is a common sign of a dead speaker. If your speaker does not respond to the audio signal and you do not feel any vibrations when touching the cone, your speaker is blown.

In this case, I recommend swapping speakers to eliminate the wiring problem, especially in older cars. If, after changing the speakers, the same one is silent, it means there is no closed circle through the voice coil, and the speaker is blown.

In each of the above cases, we have to cross-check the faulty speaker to determine if it is blown, and we should check both infinite impedance and continuity.

Correctly functioning car speakers have impedances depending on the model, either 2 or 4 ohms, and if the speaker is good, the measured value shown on the multimeter should be similar.

If you see on display very high or sometimes infinite impedances, the speaker is blown.

When checking continuity, make the same connection to the speaker terminals, and if the multimeter shows no value, your speaker will be replaced or repaired.

Can I fix the blown car speaker?

We can repair any speaker, but repairs of blown speakers are complicated, expensive, and not always cost-effective.

People decide to repair speakers usually when they are costly or unique because it may be difficult to find a replacement speaker.

Replacing a loose voice coil or suspension is complicated. If not done correctly, a sound effect after refurbishment will not be satisfactory. Therefore these refurbishments should be left to professionals.

However, if you want to repair a blown speaker, you may need to use a repair kit containing the original components of the damaged one.

If you want to learn more about the speaker’s repairs, my other article will show you how to repair the broken speaker’s cone.

Repairing the speaker is only part of it. More important is to find the reason for the speaker’s damage.

Speakers do not blow during normal working conditions, and if we do not remove the source of the problem, the same can happen to the repaired or new speaker in the future.

How to replace a blown car speaker?

When car speakers are damaged, especially original factory speakers, it creates an opportunity to replace them with new speakers, so you can enjoy listening to better quality music for a long time.

If you want to replace the speaker with a new one, you should replace a pair left and right, and it does not matter if they are in front or the back of the car.

The sound quality from factory speakers decreases over time, and if you replace only the blown speaker, you can hear the difference between left and right.

Based on my experience, and not only mine, I recommend always replacing the pair of speakers.

To replace the blown-out speaker (or the pair including the damaged speaker), we have two options:

#1. Purchase original factory replacement speakers.

Although it is the most straightforward method, we will not increase the sound quality in the car.

Sound will remain at the current level because most factory speakers offer a mediocre music experience.

#2. Replace blown factory speakers with aftermarket alternatives.

Aftermarket speakers have better quality, and in 99% of cars, they will sound better than the original models. Below are a few other benefits of aftermarket speakers:

  • They are more powerful.
  • Have a higher frequency response
  • Components of aftermarket speakers are made from better quality materials that affect their durability and lifetime.
  • Aftermarket speakers offer a large selection of types.

The remaining 1% of cases, where aftermarket speakers may not sound better than factory speakers, apply to cars equipped with high-end car audio systems, for example, Bentley with Niom system or Maserati with Bowers & Wilkins.

In such cars, blown speakers should be replaced only with the original ones.

Besides, these cars have systems built in many cases with over 20 speakers powered by several amplifiers, so it would be complicated to find direct aftermarket replacement.

It is essential to find out which speakers will fit our car. They have to have the right size and depth. Also, their power has to be aligned with the amplifier or head unit.

If you buy speakers with larger depths than current ones, you must purchase adaptors or distance rings to ensure the magnet does not touch the metal door panel and the window opens freely.

You may also need to purchase wire connection cables to attach them to the cubes in factory installations.

When buying aftermarket speakers, make sure you listen to at least several different types and choose these with the sound type you need.

Over the years, I read hundreds of reviews, but when I listen to these “top” or “best” recommended speakers and have tested them in different configurations, well…. Of course, I am not convinced by their performance, but this is my opinion.

I am pointing this out because every speaker sounds differently, and listening to them before purchasing is critical.

When you have completed all the equipment, you need to install the speakers, connect the wires, and put the door panels back in place.

How to avoid blowing speakers?

It is not always possible to keep car speakers from blowing because many reasons can cause this damage, but we can reduce the probability of car speakers blowing.

Many speakers blow because their power does not match the rest of the sound system, or the setup of the car stereo system is incorrect and causes permanent damage to the most sensitive part of the speaker, which is the voice coil.

When a voice coil is damaged, there is very little chance of repairing such a speaker.

To prevent your car speakers from blowing, you should:

#1. Use an amplifier that is within the power handling specification of the speaker.

#2. Do not use treble/bass boost controls or turn the volume too high.

#3. Use a low-pass filter on your amplifier to prevent distortion.

#4. Avoid playing music at high volumes for extended periods of time.

#5. Inspect your speakers regularly for any signs of damage or wear and tear.

#6. If using aftermarket speakers, make sure they are correctly installed according to the manufacturer’s instructions.

Let’s go below for more details on the important steps:

Use correct passive crossover, or make proper setup for active crossover.

Crossovers for systems speakers should match the speakers’ frequency and their power.

When using active crossover, you have to remember to correctly set the frequency that will be cut and not transmitted further to the speaker.

A good practice is to set the crossover’s frequency slightly higher than the manufacturer’s recommendation because the information in the speakers’ technical specifications does not always reflect the actual condition in which the speakers work.

For example, when we read that the speaker works from 60 Hz, do not precisely set the crossover at 60 Hz, but higher, like 70Hz or 80Hz.

This will reduce the speaker’s probability of blowing when playing high volume at the lowest possible frequency and increase the speaker’s lifetime.

You can compare it to driving a car at the maximum RPM, but you do not do that to the engine. The same for the car speakers. They should not play low or high frequencies at a high volume for a long time.

Do not overpower or underpower the speakers.

Overpowering or underpowering car speakers apply to most car audio systems and affect all speakers, from heavy subwoofers to little tweeters.

The easiest way to avoid supplying speakers with the wrong power level is to use an amplifier that matches the speakers. Ideally, the RMS of the amplifier is 50% more than the RMS of the speaker.

For example, if we have a 100W speaker, an amplifier should produce no more than 150W per channel. Make sure to check continuous RMS power, not any other irrelevant type.

However, having an ideal power ratio between speakers and amplifiers is not always possible. Therefore, when your amplifier is much more powerful than it should be for a particular speaker, you should reduce its gain on the steering panel.

Much more dangerous for speakers are amplifiers that cannot produce enough power for the speakers.

If this is the case, you must be careful with turning up the volume because this can cause your speakers to blow in no time.

If you want to continue listening to loud music, the right way to do it is to buy a stronger amplifier.

This will protect your speakers from being destroyed and allow them to play with a much better and clear sound quality for a long time.

Prevent speakers from physical damage.

The grill should always cover the cone in every car speaker. This is especially important for a subwoofer in the trunk.

If you want to keep your speakers in good condition, do not place anything large or sharp next to them that could damage or reduce the cone’s free movements.

Use the proper size enclosure.

This also applies mainly to the subwoofers. Make sure the subwoofer box is not too large. Otherwise, too high vibrations of the cone can destroy the speaker’s surroundings or suspension.

It is better for the speaker when it is placed in a box that is too small than too large.

Conclusion

Car speakers are delicate components and require attention to detail when installing, setting up, and using them. So why do car speakers blow?

Most of the time, it is due to incorrect installation or setup and lack of maintenance over time.

Following the steps outlined above should help you keep your car audio system functioning correctly for a long time. Happy Listening!