A good loudspeaker can make a big difference when you listen to your favorite song or watch a special effects movie, but have you ever wondered how the device you are using can produce such good sounds? Like many other electronics, a speaker’s internal biology consists of coils and magnets, among other hardware. It is the combination of these that allows you to experience the ‘heaven’ of sound.
Bigger magnets make better speakers because the quality of a speaker is determined by the length of the coil and the magnet’s weight. The amount of power your speaker can handle depends on how efficiently the power can be converted by the opposing magnetic field of the coil and the magnets.
Continue reading to find out what this means and exactly how a magnet size affects the speaker’s quality.
Does the Size of the Magnet Affect the Quality of the Speaker?
Depending on the type of magnet used (I will discuss in detail below), the magnet size can determine your speaker’s quality.
In the most basic of terms, a heavy magnet will give you better efficiency and more bass response.
In contrast, a light magnet will lead to lower efficiency and potential issues with feedback or crackling in the sound, along with less bass response.
In general, when it comes to magnets and speaker quality, just remember: the bigger, the better.
What Does the Magnet Do on a Speaker?
Speakers are energy transducers that convert audio signals (electrical waves/energy) into sound waves (mechanical waves).
They rely on the principle of attraction and repulsion of electromagnetic waves by permanent magnets to convert electrical energy into mechanical energy and then back into electrical energy.
This means that they utilize electromagnets to turn the music’s AC voltage into diaphragm movement in a magnetic field and turn it into sound.
Does the Size of the Magnet Matter?
To answer this question, let’s first understand how a speaker works. A speaker is composed of a cylindrical coil connected to a cone of paper or a different composite material.
A magnetic field is produced when electrical energy flows through a wire on the coil. The strength of the magnetic field produced depends on the length of the wire.
When changing audio signals are sent from the amplifier to the wire coil, it produces a changing magnetic field that matches the original sound.
The changing magnetic field then plays ‘push and pull’ with the permanent magnet’s magnetic field.
This makes the speaker membrane vibrate, and the membrane vibration causes air molecules to vibrate as well. This vibration of the air molecules is the sound that reaches your ears.
From the above information, it is clear that using bigger magnets and additional turns of wire on the coil creates a bigger opposing magnetic field. The opposing magnetic field, in turn, leads to a higher vibration of the membrane and hence higher or better quality sound.
The size of the magnet also depends on the type of magnet used. As you will see below, Neodymium magnets tend to have better efficiency than the other two.
Remember that a bigger magnet’s effect will depend on the changing magnetic field produced by the wires’ electrical energy on the coil.
Types of Magnets Used To Make Speakers
Different kinds of magnets can be used when manufacturing speakers. For example, high-end speaker brands use rare earth Neodymium magnets. These are the strongest kind of permanent magnets available in the market today.
Neodymium Magnets
Neodymium magnets were invented in the 1980s and have since become the ultimate go-to for high-quality electromagnetic audio transducers.
They are used for headphones, microphones, speakers, and other high-end products requiring strong electromagnetic waves.
They are made from a material that combines neodymium, iron, and boron (Nd2Fe14B). As a result, they produce very strong magnetic fields.
They are also known to weigh considerably less than all other magnets in the market.
Alnico Magnets
Other speakers use Alnico, which is made from iron, aluminum, nickel, and cobalt, making them robust and durable.
These were the first kind of magnets used in the 1950s to make speakers and are still a good choice as it produces a strong magnetic field, and it has high coercivity.
Ceramic Magnets
Ceramic (also known as “Ferrite” magnets) is another magnet that can be used for speakers. They are meant to be an affordable type of Alnico and are made from iron oxide and strontium carbonate.
These are the most affordable type of permanent magnet and are medium in strength but sometimes don’t make a very good magnet for speakers.
Factors To Consider When Choosing a Good Speaker
Are you looking to upgrade your speaker and are not sure what you should be looking for? You came to the right place.
Below are some of the important speaker specifications that you should consider when searching for a good speaker.
Sensitivity and Efficiency
A speaker’s sensitivity (also known as speaker efficiency) will tell you how much power a speaker will convert into sound. What you hear from a speaker is the final product of what was sent into the speaker by the amplifier.
In converting the audio signals received from the amplifier into sound signals, some of them are wasted and turned into heat by the speaker. The more the wattage, the less sound that will come out.
The whole point of having a speaker is to get the maximum conversion possible to feel the song or movie’s effects to the maximum. All speakers will waste some of the power received from the amplifier.
The trick is to ensure that the speaker is as efficient as possible and can convert as much energy coming from the amplifier as possible.
For speakers, the lower the dB level, the lower the efficiency. For example, a 95 dB speaker is more efficient than a 88 dB speaker.
When buying a speaker, you will notice that the price goes up as the numbers go higher. But always remember: you get what you pay for.
Power Rating
Like speaker sensitivity, the power rating is an important speaker specification that tends to be very misunderstood.
First, you need to understand that speaker power rating and amplifier power rating are two different aspects.
A speaker does not produce power – an amplifier does.
Hence, the power rating on the speaker specifications only refers to how much power a speaker can safely receive from the amplifier (measured in watts).
If the power exceeds this, the speaker will start to get hot before it distorts and breaks. Most times, a speaker will have a minimum and a maximum power rating.
Therefore, this rating is very important to note so that you do not input an amplifier channel above the speaker power rating and end up destroying your speaker.
Impedance Matching
Impedance is to alternating current (AC) is what resistance is to direct current (DC). In simple terms, impedance matching describes how hard it is for an electrical circuit to send an electrical current through. So for speakers, the higher the resistance, the harder it is to receive power from the amplifier.
The truth is, all speakers have impedance – you will not find a speaker that has perfect transfer. Speaker’s impedance mainly depends on the size and design of the speaker.
The impedance will be indicated on speaker specifications as a nominal value. This means that it is an average figure, and it might be lower or higher.
When matching a speaker to an amplifier, try to match it with the impediment indicated on the amplifier. Matching with an amplifier that is not suitable can lead to overheating the amplifier and eventually destroy it.
Related article: 10 Common Amplifier Problems and How To Fix Them
Conclusion
The simple answer is that bigger magnets do make better speakers. But there are other factors to be considered to make this true. Increasing the size of the magnet in a speaker on its own will not give you better sound.
The trick is to match the changing magnetic field produced by the wires in the coil to the magnetic field produced by the magnet.
