If you are planning to buy a Hi-Fi music system, you might have come across terms like tweeters, mid-range drivers, and woofers—but what do these terms mean?
Also, do these driver configurations offer better sound quality?
How Do We Hear Sound?
Before getting into speakers and how they work, it’s essential to understand how sound is created. Simply put, sound is a vibration reaching your ear.
In the case of a musical instrument like a drum, the sound is created by physically generating vibrations by hitting the cymbal or the bass drum. Once struck, the drum skin vibrates, creating a pressure wave in the air molecules close to it, generating a sound wave. This sound wave is nothing but a set of compressions and rarefactions traveling through the air.
On reaching your ear, these vibrations vibrate the eardrum, enabling you to hear the sound of the drum.
The human ear can only hear sounds between the frequencies of 20Hz-20,000Hz. Our ears cannot process anything outside this range. Plus, as humans age, our audible range also tends to decrease.
How Do Speakers Work?
Now that we have a basic understanding of how sound is created, we can look at how speakers create sound waves.
Unlike a drum, which creates sound waves by vibrating the drum skin, a speaker uses concepts of magnetism to create sound. Put simply, a speaker uses three main components to create sound waves, and put together, it is known as a driver. A brief overview of the same is given below:
- Diaphragm: Like a drum has a skin, a speaker uses a diaphragm to create vibrations. This diaphragm is a thin membrane made of paper, metal, or plastic connected to the voice coil.
- Voice coil: As the name suggests, the voice coil is a coil of copper that acts like an electromagnet when current passes through it. The current in the voice coil changes based on the audio signal vibrating the diaphragm.
- Permanent magnets: The diaphragm and the voice coils are placed between a set of permanent magnets. This combination of permanent magnets and electromagnets is what creates sound.
Now that we have a basic understanding of the components that make up a speaker, we can look at how it works.
In most cases, the speaker is connected to a digital device like a computer or a DAC. These devices send audio signals to the speaker that are then processed and sent to the voice coil. These audio signals are a combination of different sine waves.
Once these sine waves reach the voice coil, they induce a varying current in the voice coil—converting it into a magnet that changes its polarity based on the input signal.
Now, as the diaphragm and voice coil are surrounded by the magnetic field of a permanent magnet, an attraction/repulsion force is applied to the voice coil based on the polarity of the magnetic field it possesses.
It is this basic mechanism of temporary and permanent magnets that helps speakers recreate music with great accuracy, but there is a catch; a single diaphragm can’t do it all.
Tweeters, Mid-Range Drivers, and Woofers Explained
You see, the music we listen to can have sounds varying from 20Hz to 20,000Hz, and a single diaphragm cannot vibrate to generate such a wide variety of frequencies. Therefore, a speaker uses diaphragms of different sizes to solve this problem.
Due to the difference in diaphragm size, different drivers reproduce certain frequencies with better accuracy. This size difference creates tweeters, mid-range drivers, and woofers.
Tweeters create high-frequency sounds. Although different speakers have different frequency ranges for tweeters, in most cases, tweeters are used to create sounds in the 2,000Hz to 20,000Hz frequency range.
As the tweeter has to produce sounds in a high-frequency range, it uses a diaphragm with a small diameter. Due to the small size, the tweeter can vibrate at higher frequencies creating shrill sounds with great accuracy. Not only this, but the small diaphragm design enables the tweeter to work well without consuming a lot of power.
As the name suggests, mid-range drivers are designed to reproduce sounds in the middle of the human audible frequency range. Usually, these speakers work in the range of 500Hz and 4,000Hz. Due to this frequency range, the output of the mid-range tweeters is fairly flat.
That said, most of the vocals and instruments in any music composition are in the mid-range frequency, making it essential to have a driver that works well when generating these frequencies.
In terms of diaphragm size, the mid-range driver lies between the tweeter and the woofer.
The woofer on a speaker system produces the lowest part of the frequency spectrum and adds the bass to all your music. In terms of the frequency range, most woofers work in the 20Hz to 2,000Hz range.
To create these low-frequency sounds, the woofer uses a large diaphragm enabling it to vibrate a lot of air molecules. That said, due to its large size, the woofer cannot vibrate at very high speeds, preventing it from generating high-pitched sounds.
Another thing to note about woofers is that the enclosure they are placed in also affects the bass they produce. Due to this reason, most speaker systems place the woofer in an independent cabinet to offer a better bass response.
How Does the Audio Signal From Your Computer Reach the Different Drivers?
When you play music on your speakers, a single audio stream makes its way from the computer to the speaker. This audio signal is then divided by the crossover network based on the speaker design.
The crossover network is an electronic device that segregates the frequencies in an audio signal into different subfrequencies.
So, if you have a speaker with a tweeter, a mid-range driver, and a woofer, the audio signal from your computer will be divided into three parts. One for the woofer, which consists of the low-frequency audio signal. Secondly, an audio signal in the mid-frequency band for the mid-range driver, and lastly, a high-frequency audio stream for the tweeters.
All these signals are sent to the different drivers simultaneously, offering an immersive audio experience.
Should You Buy a Speaker With Several Drivers?
The music we listen to is an amalgamation of several frequencies. Therefore, using a single-driver design to reproduce music produces mediocre sound.
So, if you are looking for a phenomenal sound experience, you should get a speaker with dedicated drivers designed to generate specific frequencies—offering a more immersive music experience.