How Do Speakers Work? Speakers and Sound Production Explained

Speakers have been around for a long while now, and are found in everything from laptops, televisions, malls, restaurants, phones, and more. Despite being found in most gadgets and just about anywhere, not many have satisfied their curiosity about how speakers produce sound or how wireless speakers work. Fortunately, the science of how speakers make sound can be made easy to understand by dividing the process into digestible explanations. If you want to know how speakers work, then you found the right article.

How a Speaker Works

How do speakers work to create sound? To produce sound, speakers function by converting the gathered electrical energy into mechanical energy. As the air is compressed by mechanical energy, the motion is converted into sound pressure level (SPL) or sound energy. A magnetic field is generated when an electric current travels through coils of wire. In speaker systems, the electrical current travels through the system’s voice coil, which generates an electric field that is then associated with the magnetic field found within the speaker.

The concept of similar charges repelling one another and opposite charges attracting can be found in the production of sound within audio systems. When the audio signal travels through the voice coil, musical waveforms begin to rise and fall, which is essentially the repelling and attraction of the voice coil with the permanent magnet.

This produces the back and forth motion of the voice coil, which is what gives it that cone-like structure. From the alternating motion, pressure waves are in the air, which is what we hear as sound.

 

Step-by-step Process of How do Speakers Produce Sound

Step 1. The Generation of Initial Musical Waveform

After powering the sound system from zero, the output voltage serves as a representation of the initial musical waveform, which starts by beginning to rise. The generated electrical current then begins passing through the sound system’s voice coil by bouncing alternately between the negative and positive sides.

Step 2. A Magnetic Field is Generated around the Voice Coil

As a result, a magnetic field is produced surrounding the voice coil, which has a similar polarity to the magnet found in the speaker frame. The identical magnetic fields repel one another, while the opposites are drawn to each other.

Step 3. Air Pressure is Generated

The diaphragm or cone then proceeds by starting to move forward, which produces air pressure. This air pressure produces the audio that people perceive and hear as sound.

Step 4. The Increase in Current Leads to An Increase in the Magnetic Field Strength of the Voice Coil

The rising of the electrical signal voltage towards the upper sine wave of the musical signal translates to an increase in electrical current, which also allows an increase in the magnetic field strength of the voice coil.

Step 5. Further Outward Extension of the Cone

The overall increase allows the cone to project out further.

Step 6. Current Drops to Return the Diaphragm to the Initial Closed Position

After the signal flows by the highest possible output, it starts to decline. Accordingly, the electrical current also begins to decline, bringing the diaphragm closer to its initial off position at zero voltage.

Step 7. The Signal Returns to the Zero Position and the Diaphragm Returns to the Initial Position

The signal eventually reaches its zero position or “zero voltage crossover threshold”, and the diaphragm is returned to where it began.

Step 8. The Signal Starts Its Reverse Process

The signal then starts the process in reverse, while also changing into a negative voltage. During this change, electrical current travels from the negative area of the voice coil to the positive area, which produces a magnetic field in reversed polarity.

Step 9. The Action of the Magnetic Field Causes the Diaphragm to Move

Since the magnetic field of the voice coil is the opposite of the magnet found in the speaker, an attraction begins and the diaphragm starts to travel from the front side to the back. This is the opposite of the original path of back to front.

Step 10. The Diaphragm Travels in Reverse

As the electrical signal proceeds its path, the diaphragm also travels in reverse. This produces the sound waves’ other half, which was made through the air motion.

Step 11. Stereo Output or System Amplifier Returns to Initial Point. New Cycle Starts

The stereo output or system amp will then return to its initial point at zero, where the following signal starts to form as another electrical signal voltage begins to rise. This will start the cycle again, and keep repeating when the audio system is in play.  

In essence, speakers are powered by electrical signals, which transform into mechanical energy that produce air motion, creating sound.

What Separates a Good Speaker from a Bad One?

The ideal sound test for speakers is done by comparing the similarities of the waveform or pressure wave in the air to the electronic wave or audio recording that passed through the system amplifier. The frequencies are reproduced to be heard by a listener, who determines whether the frequency sounds are accurate and without any change. If the frequency accuracy is high and does not alter any detail, then the speaker is likely to be an excellent one. Otherwise, low-frequency accuracy with some noticeable change in information can indicate lesser audio quality. For a great option of speakers,  soundcore 3 offers exceptional value for money.

Testing speakers involve a handful of factors that determine the audio accuracy and overall listening experience. These speaker factors include details such as the audio dispersion, distortion, and frequency response. Among the determining factors, the frequency response is the most important and has the most significant effect on the audio. 

Importance of Frequency Response

In essence, the frequency response is the speaker system’s loudness across varying frequency levels. This means that the frequency can have varying output quality with each level of frequency. In testing frequency, varying frequency levels are sent from the system’s lows to mids, then all the way up to the highs and treble to determine whether the audio remains the same across each level. Ideally, the best frequency for a speaker system is flat, which means that the frequency does well in retaining the same level from the highs, to the mids and lows.

Frequency response generally aims to ensure that audio is heard as it is intended to sound to other people. The frequency response essentially helps determine audio accuracy across different frequency levels. The best audio and listening experiences tend to produce sound with a flat frequency response, which is likely to sound crisp and ideal on just about any playback system.

Frequently Asked Questions about How do Speakers Work

How Fast Does a Speaker Vibrate?

The vibration frequency or speed of a speaker depends on the audio system’s design, specifically the audio signal frequencies found in the audio drivers. The sound range generally varies from 20Hz to 20 kHz, with many speakers able to vibrate within an audible range with lower bandwidth.

How Does Sound Travel Through a Speaker? 

The speaker generates sound as a result of vibration or motion in the air. Aside from air, sound can even pass through solids and liquids, with speakers that we listen to having transmitted through the air as the medium. Every time an object vibrates, the air particles surrounding it moves.   

Why Do Speakers Have Magnets? 

All speakers or amplifiers have an electrical current that they utilize for producing sound. When electrical current transforms, it forms a magnetic field. To make the speakers’ cone vibrate, built-in magnets are included to produce a magnetic field in opposition to the electrical current’s magnetic field. Since the two magnetic fields are opposing and repel one another, vibrations are created, which produce the sound we hear.

Conclusion

The curiosity of knowing how speakers work does not have to be suppressed by the intimidating science of speakers and can be made easy to understand through a concise breakdown of the process of speakers and how they work. In the end, discovering something new about something so common in everyday life like the speaker, is well worth the effort.