Subwoofer Magnet: Speaker magnets fundamentals explained

If you have a top-notch audio system in your home or vehicle, it will undoubtedly feature a subwoofer.

Subwoofers are specialized speakers designed to handle low frequencies of sound measured in Hertz (Hz).

While there are many components that go into a successful subwoofer, the magnet is the most essential.

This is simply because a magnet creates vibration by creating a magnetic field that results in the actual sound we hear.

In this post, we’ll discuss the role of a magnet in a subwoofer and its types.

Key Takeaways 

  • A subwoofer is basically a type of speaker designed to produce low-frequency sound i.e. bass.
  • There are different types of magnets used in audio systems including the subwoofers. Some of the common types of magnets include Neodymium, Ferrite, and alnico.
  • A speaker’s excursion directly affects its ability to produce low-frequency energy.
  • Subwoofers with strong magnets help to increase the driver’s responsiveness and power.

Subwoofer Parts

Low-frequency sounds are produced by a subwoofer through a variety of components.

Here are some common and important parts of a subwoofer.

  • Bottom plate
  • Pole piece
  • Magnets
  • Spider
  • Basket
  • Voice coils
  • Terminals
  • Tinsel Leads
  • Cone
  • Surround (usually made of treated foam and rubber)
  • Dust Cap
  • Subwoofer Enclosure

I have covered a detailed and in-depth article on subwoofer parts and fundamentals here.

Also Read: Active vs Passive Subwoofer (Difference Explained)

What does a subwoofer magnet do?

The straightforward answer is that the magnet in a subwoofer helps create an electromagnetic field that interacts with the voice coil in the speaker cone.

An amplifier or a receiver passes an electrical current to power the subwoofer.

When the electrical current passes toward the voice coil creates an electromagnetic field. The electromagnetic waves interact with the magnets resulting in tremendous force.

The generated force moves the cone back and forth and creates pressure waves in the air.

The pressure waves finally move through the room in the form of sound or music.

Now hopefully you know the importance of a magnet in a subwoofer or in any electronic sound system.

Some facts about Magnets:

  • A powerful magnet in a subwoofer possesses a greater ability to move air quickly and accurately.
  • The quicker movement of air allows it to produce louder and more controlled bass tones.
  • You will typically find powerful magnets equipped in high-end subwoofers to produce higher-quality sounds.
  • Finally, the type of magnet used in subwoofers is another factor to look into as they play an important role when it comes to quality, efficiency, durability, and sustainability.
  • The quality of the magnet directly affects the sound quality.
  • Smaller magnets with high excursion can be more powerful than poorly built subs with large drivers.

Here’s a quick illustration of how the subwoofer magnets move.

Subwoofer moving parts Illustration (Diagram)

Moving Coil Subwoofer Driver Diagram

Also Read: Subwoofer Low Pass Filter (LPF ) Explained

Types of magnet in subwoofers

When it comes to sound quality, the type, size, and weight of drivers dictate the driving force of the speaker.

Since not all subwoofers are the same in terms of frequency, size, and shape different types of magnets are used for different purposes.

Here are the common magnet material types used in speakers by manufacturers.

Neodymium Magnets

Neodymium magnets are the most popular and are preferred for high-end subwoofers, tweeters, and speakers.

These magnets have rear-earth metal properties as they are made from an alloy of neodymium, iron, and boron (NdFeB).

Moreover, these magnets also contain a few elements such as praseodymium (Pr), aluminum (Al), dysprosium (Dy), and niobium ((Nb).

Neodymium magnets are referred to as permanent magnets in their category and are quite expensive comparatively.

That being said, they offer great results when it comes to performance, and the best part is they are lightweight.

When it comes to size, neodymium magnets are smaller and lighter than their counterparts, making them a great choice for subwoofers with smaller footprints.

These magnet types pack a lot of punch due to their ability to create stronger magnetic fields and higher power handling capabilities.

Another factor that makes them an ideal choice is that these magnets carry a wide frequency response range and can produce high-quality bass tones with ease.

Ferrite Magnets

Ferrite magnets are lighter and affordable and thus popular in most applications such as refrigerators, electric motors, and speakers or subwoofers.

These magnets are made of ceramic, iron, barium, and strontium which makes them more durable.

They are an ideal choice for marine audio because they are naturally resistant to corrosion.

Additionally, these magnet types are best at sustaining magnetization at high temperatures compared to their counterparts that tend to lose magnetization in similar conditions.

However, ferrite magnets can hold a limited frequency response range compared to neodymium magnets, so if you’re looking for higher-quality bass response you might want to do more research.

Alnico Magnets

Alnico magnet is named after its elements as it is an alloy of Aluminum, Nickel, and Cobalt (Al-ni-co). That being said, Iron, copper, and titanium properties are also found in alnico magnets.

Due to their cobalt content, they are slightly more expensive than ferrite magnets but have better magnetic strength and power-handling capabilities.

Alnico magnets also have a wider frequency response range and can produce higher-quality bass tones.

Moreover, they tend to hold magnetic power at higher temperatures too.

These types of magnets are typically silver or gray in color and will usually add some extra weight to the subwoofer design.

However, Alnico magnets aren’t that popular nowadays compared to the demands they had in the past.

Also Read: 2 ohm vs 4 ohm subwoofers: Ohm difference explained

Are bigger magnets better for subwoofers?

The choice of magnet size in a subwoofer depends on its design, purpose, and frequency range it is intended to reproduce.

Bigger magnets are generally preferred for subs dealing with lower frequencies, while smaller and more precise magnets are often used in tweeters and other high-frequency speakers to achieve better accuracy and clarity in sound reproduction.

Also Read: How to wire subwoofers? (Includes Subwoofer wiring diagram)

How do you know how powerful a subwoofer is?

The power output of subwoofers is measured in watts, which means that the higher the wattage, the more powerful and powerful the subwoofer.

For example, a 100-watt subwoofer will generally have more bass impact than a 50-watt subwoofer.

Suppose you have two subwoofers with 200 (Subwoofer A) and 400 watts (Subwoofer B), respectively.

Subwoofer B will be more powerful, delivering deeper and more intense bass due to its higher wattage.

It can handle demanding low-frequency sounds without distortion, making it ideal for larger rooms.

Also Read: Woofer VS Subwoofer: Difference between woofer and subwoofer explained

Wrap Up

Magnets in subwoofers play a vital role in creating distinct sound signatures.

From neodymium to ferrite and alnico magnets, each type brings its own unique qualities to the table.

In short, subwoofer magnet products are at the heart of every audio system, and understanding their role and types can help you make more informed choices when building or upgrading your sound setup.

The right magnet choice can significantly impact the quality, efficiency, durability, and sustainability of your audio system.

Frequently Asked Questions

Do subwoofers really need magnets?

Yes, magnets are one of the most important components because subwoofers require magnets to create powerful vibrations in order to produce sound.

Does excursion matter in the subwoofer?

Since subwoofers create pressure waves by moving large volumes of air excursion plays a key role in producing low-frequency energy. The lower-frequency drivers are designed in such a way that they move more air and travel farther than their higher-frequency counterparts.

Are there magnets inside of headphones?

Yes, just like subwoofers, headphones too require a magnetic field for the driver to produce sound, making them an essential component of the speaker system.

What makes the subwoofer sound like a popping noise?

A popping noise in a subwoofer can be due to a problematic voice coil, connection issues with the amplifier, or worn-out wires. A professional inspection is recommended to diagnose and resolve the issue.

Armed with a Diploma in electrical engineering and a remarkable 12 years of expertise, he excels in rejuvenating music systems, washing machines, dryers, and laundry-related appliances. Manish's profound insights and practical know-how establish him as a credible authority in appliance and music system repairs. Contact: manish.singh (at) subwooferblog.com. He's always ready to lend a helping hand!