Neodymium magnets in speakers: Uses and fundamentals

A magnet is one of the essential components in subwoofers and Neodymium magnet is simply a type of magnet used in these applications.

In simple words, neodymium magnets are one of the popular types of magnets used in subwoofers and speakers.

Key Takeaways

  • Subwoofers and Speakers use different types of magnets to create a magnetic field which further helps in the movement of the voice coil and the cone.
  • The vibration or the movement of these components results in the actual sound we hear.
  • Neodymium magnets are permanent magnets made from rare earth elements such as an alloy of neodymium, iron, and boron.
  • Subwoofers that use neodymium magnets are also referred to as neo-subs.

What are Neodymium speaker magnets? (Explained)

Neodymium speaker magnets are a type of rare-earth magnet known for their remarkable magnetic properties.

Composed primarily of neodymium, iron, and boron, collectively known as NdFeB, these magnets are crafted through sophisticated manufacturing processes to yield powerful and compact magnets with extraordinary strength.

Such magnets are the most widely used in speakers due to their superior magnetic properties.

When compared to traditional ferrite magnets, neodymium magnets allow higher magnetic energy, resulting in stronger and more efficient speaker performance.

Also Read: Subwoofer parts explained (Anatomy of subwoofer speaker)

Neodymium Magnet composition

Neodymium magnets are commonly manufactured using two processes i.e. the traditional powder metallurgy (also known as sintered magnet) approach and the quick solidification (also known as bonded magnet) procedure.

Comparatively, the sintered magnet manufacturing processes are more expensive because this particular production results in stronger and more robust Rare Earth Magnets.

Neodymium magnets are composed of a combination of three main elements:

  • Neodymium (Nd)
  • Iron (Fe)
  • Boron (B).

Neodymium (Nd)

Neodymium is a rare-earth element and a key component that provides the magnet with its high magnetic strength, making it super strong.

Neodymium’s atomic structure makes it possible for magnetic regions to be strongly aligned., thereby creating a strong magnetic field.

Iron (Fe)

Iron is another essential element in the composition of neodymium magnets.

It helps to stabilize the magnetic field and is responsible for improving the temperature resistance of the magnet.

The presence of iron ensures that the magnetic properties remain stable under varying temperature conditions.

Boron (B)

Boron is added to the mix to enhance the magnetic properties of the neodymium magnet.

It facilitates the alignment of iron and neodymium atoms, contributing to the magnet’s strong magnetic field.

The composition of neodymium magnets is typically expressed in a chemical formula like Nd2Fe14B, indicating the relative proportions of neodymium, iron, and boron atoms in the magnet.

That being said, the exact composition may vary slightly depending on the specific manufacturing process opted by speaker manufacturers.

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Does high or low temperature affect the strength of the neodymium?

The strength of neodymium magnets can be influenced by temperature changes.

Elevated temperatures can notably impact the strength of neodymium magnets, leading to a decrease in their performance.

This is attributed to the fact that neodymium magnets have a maximum operating temperature, and once this threshold is surpassed, their magnetic properties begin to deteriorate.

The specific temperature at which this decline occurs may vary depending on the magnet’s grade and composition.

Nevertheless, these natural magnets gradually lose strength as the temperature rises above their designated maximum operating temperature.

Conversely, low temperatures typically have a lesser effect on the strength of neodymium magnets. They usually perform well in cold environments without experiencing significant magnetic strength losses.

Here is a quick diagram representing how neomagnets react at different temperatures

diagram showing how nedymium magnets react at different temperatures

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Why are neodymium magnets expensive?

There are a few factors to consider that make neodymium magnets expensive such as magnetic flux and its structure.

Here are a few common reasons why these magnets cost a little bit higher.

Magnetic Flux

Magnets with Neodymium, iron, and boron compositions have strong coercivity (magnetic flux) at higher temperatures compared to other types of magnets.

The increased magnetic flux leads to greater control over the speaker cone, enabling precise and accurate sound reproduction.

Moreover, these magnet types are strong and durable and hence they are expensive.

When the temperature rises close to 100°C (212°F) or above, the neomagnet’s coercivity decreases drastically.

To overcome this situation or sustain the magnet’s performance during temperature changes, terbium (Tb) or dysprosium (Dy) is added to its composition.

Note: Terbium or Dysprosium is another form of a rare-earth element that has a high magnetic susceptibility. Hence, their inclusion makes the neodymium magnets more expensive.

Enhanced Audio Performance

One of the key advantages of neodymium speaker magnets lies in their ability to produce stronger magnetic fields.

When integrated into speaker systems, these magnets interact with the voice coil, resulting in enhanced driver performance. 

Structure and strength of neodymium

Neodymium magnets are stronger, lighter, and quite durable when compared to their counterparts.

The compact size with strong power helps manufacturers come up with a speaker design that is compact without compromising the power.

These special qualities together contribute and justify their value i.e. their increased cost. 

So, next time when you see that the speaker’s magnet is small and yet is overpowering the larger loudspeaker, it’s highly likely that the smaller speaker is using Neomagnet.

Here are the other factors that make Neomagnets so expensive and special

why Neodymium magnets are expensive - Diagram showing features and reason

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The downside of using Neodymium Magnet material in a Subwoofer

While neodymium magnets offer numerous advantages, they also have some downsides that should be considered when using them in certain applications:

Cost factor

Neodymium magnets can be more expensive than traditional ferrite magnets.

The high cost of neodymium magnet material can impact the overall price of subwoofers or other products that utilize these magnets.

Fragility and brittle

Neodymium magnets are more brittle compared to ferrite magnets.

They can chip, crack, or shatter if subjected to impact or excessive mechanical stress. Care must be taken during handling and installation to avoid damaging the magnets.

Corrosion Susceptibility

Neodymium magnets are susceptible to corrosion when exposed to moisture or humid environments.

Special coatings or platings are often applied to protect the magnets from corrosion, but in certain conditions, their lifespan may still be reduced.

Temperature Sensitivity

Neodymium magnets have a lower maximum operating temperature (Curie temperature) compared to some other magnet types.

In high-temperature environments, their magnetism can decrease, leading to reduced performance.

Magnetic Shielding

The strong magnetic field generated by neomagnets can cause interference with nearby electronic devices.

Proper magnetic shielding may be required to prevent unwanted effects on sensitive equipment.

Manufacturing Challenges

Producing neodymium magnets involves complex and specialized processes.

Limited availability of rare earth elements, from which neodymium is derived, can lead to supply chain challenges and fluctuations in pricing.

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

How long do neodymium magnets last?

Neomagnets, commonly referred to as permanent magnets, lose a small amount of their flux density every 100 years. That being said, the rate of corrosion and heat have a significant impact on the reduction in flux density.

So, yes in the very long term, it may lose the flux density a little bit, but if it’s kept properly, it will keep the magnetic properties intact forever.

Also read: Pairing Soundbar and subwoofer: Add a Subwoofer for bass

Which speakers have neodymium magnets?

Neodymium magnets are commonly used in various speaker systems and subwoofers due to their strong magnetic properties and compact size.

Many portable and high-end speakers, as well as some home theater systems, incorporate neomagnets to ensure high sound quality by keeping the size and weight factor in check.

Furthermore, it is also common to find neomagnets in portable Bluetooth speakers, high-quality bookshelf speakers, subwoofers, and certain premium home theater speaker setups.

Also Read: Subwoofer Low Pass Filter (LPF ) Explained

Are neodymium and ceramic magnet speakers the same?

Neodymium and ceramic magnet speakers are not the same.

The main difference lies in the material used for their magnets, Neodymium magnet speakers use neodymium, a rare earth element, which allows them to be smaller and lighter while maintaining strong magnetic fields.

On the other hand, ceramic magnet speakers use ceramic ferrite magnets, which are larger and heavier but offer good performance at a more affordable cost.

Neodymium speakers are often preferred for applications where weight and size are critical, such as portable devices, while ceramic magnets are commonly used in larger, cost-sensitive applications like guitar speakers and some PA systems.

Also Read: Subwoofer Placement Ideas for deep bass (Find the best spot)

Neodymium Speaker Magnets vs Ferrite Magnets

PropertyNeodymium Speaker MagnetsFerrite Magnets
Magnetic StrengthHighModerate
Size and WeightSmaller and LighterBulkier and Heavier
Sound QualityExceptionalGood
Energy EfficiencyHighModerate
CostRelatively ExpensiveEconomical

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Final Thoughts

Speaker technology may vary from manufacturer to manufacturer depending on the desired outcome.

Since the use case and the budget will decide the build, not every speaker driver will use Neo or NIB magnets.

Their use in high-frequency drivers like tweeters drastically lowers the distortion levels across the audio spectrum, improving the overall sound quality, especially at high frequencies.

So, the bottom line is if you want a strong driver with a smaller size that is not only sturdy but can outperform its larger counterparts without affecting weight or depth, go for subs or speakers made of neomagnets.

Frequently Asked Questions

Are neodymium tweeters good?

Yes, neodymium tweeters are generally considered good. They offer high efficiency, clear and detailed sound reproduction, and are commonly used in high-quality audio systems.

Why are neodymium magnets so strong?

Neodymium magnets are strong due to their high maximum energy product (BHmax) value, measured in Mega Gauss Oersteds (MGOe). This value indicates their exceptional ability to deliver magnetic energy, making them one of the most powerful and widely used types of magnets.

Can neodymium magnets be electromagnetized?

Neodymium magnets themselves cannot be electromagnetized. They are a type of permanent magnet, which means they retain their magnetic properties without the need for an external power source. Unlike electromagnets, which require an electric current to produce a magnetic field, neodymium magnets are always magnetic.

What type of magnets do loudspeakers use?

Loudspeakers commonly use permanent magnets, with ferrite and neodymium being the most prevalent types. These magnets create a magnetic field that interacts with the voice coil, allowing the speaker to produce sound. Also, it’s important to note that loudspeakers or any speaker consist of an electromagnet and a permanent magnet.

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!