Skip to main content

Select preferred language from 'Translate' hidden side menu =>

Blog Navigation

By
                              Blog Navigation 
Post a Comment

Why is a magnet used in speakers?

Image
By

What Is the Function of a Magnet in a Loudspeaker? Working Principle, Role in Sound Production, and Performance Impact

The function of a loudspeaker is similar to that of a solenoid, but a solenoid has a spring to retract the plunger that is missing in a loudspeaker.

Animation of Solenoid working.




A loudspeaker is nothing but a linear motor that generates ‘to and fro’ motion of the voice coil. The magnet is used to eliminate the mechanical spring because the speaker receives an AC signal, unlike a solenoid, which works on DC.

Speaker as an air piston: 

When AC current flows through the speaker coil, it generates alternating magnetic field poles that react with the permanent magnet used in the speaker.. 

Magnetic poles interaction:

We know that there is attraction between opposite poles and repulsion between similar poles.

Animation describe atractive/repulsive forces of magnetic poles

Hence, the speaker's voice coil is pulled in and pushed out from its neutral position because of this interaction.

Animation shows working of Speaker

What is a sound wave? 

A speaker is nothing but an air piston; the diaphragm rapidly moves in and out to compress and expand air molecules to generate sound.

Sound wave generation

FAQ Set:

Q1: Why do loudspeakers need a magnet?

The magnet creates a static magnetic field in which the voice coil moves, converting electrical signals into mechanical motion and producing sound.

Q2: How does the magnet work with the voice coil?

When an audio signal passes through the voice coil, it generates a magnetic field that interacts with the permanent magnet, causing the coil (and attached diaphragm) to move and produce sound waves.

Q3: What types of magnets are used in loudspeakers?

Common types include ferrite magnets, neodymium magnets, and alnico magnets, each offering different strength, size, and cost characteristics.

Q4: How does the magnet affect loudspeaker performance?

The magnet’s strength and quality determine efficiency, sound clarity, sensitivity, and the diaphragm’s movement precision.

Q5: Can a loudspeaker work without a magnet?

No, without a magnet, the voice coil cannot generate motion relative to a magnetic field, so no sound would be produced.

Q6: Why are neodymium magnets preferred in modern speakers?

Neodymium magnets are stronger and lighter, allowing for compact, high-performance speaker designs with improved sensitivity and frequency response.


More content related to this: 


If you like my answer, consider supporting us:

Gpay link



Comments

Post a Comment

Popular Posts

Blog Navigation

By
                              Blog Navigation 
Post a Comment
Read more

What happens to the energy stored in an inductor carrying a current?

By
Can the Energy Stored in an Inductor Be Used Practically? Applications, Benefits, and Real-World Examples. Why does an inductive load create sparking across contacts?  An inductor stores energy in the form of a magnetic field as long as current is flowing through it. As the current stops, the magnetic field began to collapse. Collapsing magnetic flux is also a rate of change of magnetic flux that will induce a large voltage spike (back EMF) across it. Energy stored in an Inductor:  Since this induced voltage is parallel to the inductor coil, it decays by converting it to heat across the coil resistance. During this process, the coil generates a magnetic field again due to the flow of decaying current through the coil, which results in electromagnetic interference during radio operation and sparking across open contacts. Adverse effects of stored energy in an inductor:  Can we put this back-EMF into use? Yes. Practical Use of Stored Energy in an Inductor:  Spark-ignit...
Post a Comment
Read more

What is biasing in electronics?

By
What is DC Bias Voltage used in Electronic circuits? — Definition, Importance & Practical Examples DC bias is simply a deliberate addition of a DC voltage to a (circuit) node to offset its operating voltage level. Voltage divider bias in a common emitter amplifier:  The most common and popular example of DC bias is the voltage divider bias in a common-emitter amplifier. What will happen if the DC bias is not given to the base of the above circuit? The transistor will act like a rectifier; it will amplify only the positive part of the signal, creating a distorted output that we don't want. Purpose: The purpose of the DC bias in the above circuit is to keep the base DC offset voltage sufficiently high to keep the base-to-emitter junction forward-biased all the time, considering the subtractive effect of the negative-going excursion of the AC input signal and power supply voltage variations. The typical value is 1.2V for the 12V VCC. Biasing is not always DC; it can be AC: AC bias...
Post a Comment
Read more