It’s a known fact that speakers are the modest boxes that pump out our favorite tunes, podcasts, and audiobooks. But have you ever stopped to think about the magic behind speakers? How exactly does that work? The answer lies in a fascinating dance between electricity and magnetism.
Intrigued? Dive deeper into the article to explore the inner workings of speakers and unveil the science behind the sound.
Why it’s Worth Knowing how the Speaker Works?
You don’t have to know all the technical stuff about speakers to enjoy music through them. But there are a couple of reasons why understanding how speakers work can be beneficial:
- Firstly, you can appreciate the technology behind the everyday miracle of turning electrical signals into music.
- A basic understanding of speaker components can help you make informed decisions while buying. Moreover, knowing the difference between a tweeter and a woofer helps you buy speakers that fit your tastes.
- If your speakers start acting up, like making weird noises or not playing loud enough, knowing a bit about how they work can help you figure out what’s wrong.
- Understanding speaker components can open doors to customization. Especially, to the ones who enjoy building speakers according to their needs.
Before learning about how the speaker works, first, let’s look at its parts.
What are the Parts of a Speaker?
Speakers convert electrical impulses into audible sound waves via a complex interplay of various essential parts. Here’s a breakdown of the key components:
- Driver (The heart of the speaker)
- Dust Cap (The small cover located at the center of the speaker cone)
- Diaphragm, often referred to as the cone.
- Suspension (Surround+Spider, supports the cone to keep it centered)
- Voice Coil (The wire coil attached to the speaker cone)
- Magnet (Create a magnetic field)
- Frame also known as the basket (The structural component that holds all driver components)
- Enclosure also called a cabinet (The housing that surrounds the driver(s))
- Terminal (The connection point where the speaker wires are attached)
How Do Speakers Work?
Speakers work on the principle of converting electrical energy into mechanical energy, and finally into sound energy. Here’s a simplified explanation of how they work:
- Electrical Signal In: The journey starts with an electrical signal from your phone, computer, or any audio source. This signal carries information about the sound, including its pitch and volume.
- Electromagnetism at Play: Now, the electrical signal arrives at the driver, consisting of a voice coil (a coil of wire) and a permanent magnet. When electricity zips through this coil, it creates a magnetic field, and then things get interesting!
- The Push and Pull: Remember how the electrical signal caused the voice coil to produce its own magnetic field? This new magnetic field spreads over the permanent magnet’s space. Recall that like poles repel, but opposites attract! So these two magnets begin to push and pull on each other, rocking the voice coil back and forth.
- Cone in Motion: As the voice coil is connected to the cone, the cone gets pulled along for the ride. Now it also starts vibrating, just like a drumhead when you hit it.
- Air Pressure Waves: Soon the cone vibrates back and forth, it pushes and pulls on the air around it. Imagine throwing a pebble into a pond and witnessing ripples. That’s what happens with the air – tiny airwaves go outward. The distance between the ups and downs of these waves determines the pitch while the height of the waves determines the volume.
- Sound Perception: Finally, those pressure waves hit your eardrums at last. The little drum-like things within your brain pick up pressure waves and convert them into sound. The pattern of the waves tells your brain what sort of music it is – high notes, low notes, loud, etc.
How Do Speakers Create Sound?
As discussed above, speakers use electrical signals and are powered by a stereo or amplifier. The speaker receives an amplified voltage (electrical signal) that replicates the musical signal from an audio source. This signal has enough power to drive the speakers.
Here is the detailed step-by-step process of how speakers produce sound.
Step-1: When you turn on the sound system, the electrical signal slowly gets stronger. This signal matches the ups and downs of the music. The stronger signal pushes electricity back and forth through the speaker’s voice coil.
Step-2: A magnetic field is created around the voice coil with the same polarity as the permanent magnet attached to the speaker basket.
Step-3: Now, the cone begins moving forward, creating air pressure and sound.
Step-4: As the electrical signal voltage rises towards the top of the sine wave in the musical signal, the current increases, and the voice coil increases its magnetic field strength.
Step-5: This increased strength pushes the cone out even further.
Step-6: The signal falls after reaching its peak. As the current drops, the cone returns to its off (zero voltage) state.
Step-7: The cone returns to its starting point when the signal approaches zero (the “zero voltage crossover threshold”).
Step-8: Now the negative voltage reverses the electrical signal. In this case, current travels from the negative voice coil side to the positive, generating a reversed magnetic field.
Step-9: The voice coil magnetic field is now the opposite of the permanent magnet that attracts it.
Step-10: Now the cone moves front-to-back.
Step-11: As the signal continues, the cone reverses, creating the opposite half of air-formed sound waves.
Step-12: Then the next audio signal begins when the amplifier or stereo output returns to zero.
Step-13: The cycle restarts when the new signal output voltage rises.
Why are Speakers Mounted in Boxes?
Speaker boxes do more than just retain the speaker driver in place. They also influence how you experience sound. Imagine the sound waves coming out from both the front and the back of the speaker cone. Without a box, these waves can overlap and cancel each other out, weakening the sound or creating distortions.
Furthermore, the box may be customized to control how air flows around the speaker. This improves the bass response, making the deep low-frequency sounds seem richer and more powerful.
Also, the box protects from outside disturbances in the room that may interfere with the music. So, speaker boxes function as quiet partners, delivering clear, strong, and well-balanced sound.
Speaker boxes make them easier to carry around. Unlike speakers with open backs, these enclosed ones are more portable and convenient to move.
Types of Speakers
Speakers fall into various groups, each with its unique sound-producing mechanism. Every sort of speaker has pros and cons, making them fit for various purposes and personal preferences. The most prominent types are dynamic, electrostatic, and planar magnetic speakers.
- Dynamic Speakers, often known as moving-coil speakers, are the most popular. They use a voice coil and a magnet to move the cone and create sound.
- Electrostatic Speakers use a narrow diaphragm sandwiched between two charged plates. When an audio signal is sent, the diaphragm oscillates back and forth, generating sound waves.
- Planar Magnetic Speakers, or ribbon speakers, have a thin, lightweight diaphragm dangled between two magnets. When an audio signal is sent, the current that flows through the diaphragm interacts with the magnetic field, causing it to move and produce sound.
Factors Affecting Speaker Sound Quality
A speaker’s sound quality is impacted by various elements, including its design, materials used, speaker size, and amplifier quality.
- The materials used in the cone, voice coil, and magnet have a significant influence on the speaker’s ability to reproduce sound precisely.
- Larger speakers can reproduce lower frequencies more precisely, while smaller ones excel at producing higher frequencies. However, innovations in speaker technology have enabled smaller speakers to reproduce low frequencies with high precision.
- A high-quality amplifier can provide clean and powerful amplification. This results in more accurate and detailed sound reproduction. On the other side, a low-quality amplifier can cause distortion and degrade overall sound quality.
How Do Speakers Work – FAQs
Ans: Speakers vibrate at different speeds depending on the music! For deep bass notes, the speaker might vibrate as slow as 20 times per second. But for high-pitched sounds, it might vibrate super fast, up to 20,000 times per second!
Ans: Speakers use magnets to push and pull the voice coil, mimicking the music’s electrical signal. This rapid movement creates sound waves.
Ans: Bigger speakers can move more air, making them better for loud sounds or deep bass. Smaller speakers are good for higher frequencies or quieter listening.
Ans: Both speakers and subwoofers use magnets and electrical signals to make sound. However, subwoofers are specially designed to handle deep bass notes. They are usually larger than regular speakers and vibrate much slower.
Conclusion
As we come to the end, we hope you have acquired a better grasp of the complexities behind this incredible technology. Every component, from the interplay of electrical and magnetic forces to the exact motions of the speaker cone, is vital for sound production. Knowing and understanding how a speaker works not only improves the enjoyment of music and audio but also helps you to make informed decisions.
