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What Does A Subwoofer Do? The World of Bass Reflex Speakers


If you are here, you are probably looking to add more bass to your sound system. The primary speakers in your sound system are in charge of playing back the higher frequencies and not so much the lower ones. Here is where a subwoofer can come in handy.

So, what does a subwoofer do? Most subwoofers reproduce low-frequency sounds. Right around the 20 Hz to 200 Hz frequency ranges, the powered subwoofer starts to produce bass notes in your sound system. These particular frequencies will add sound quality and presence to your listening environment.

Have you ever wondered what subwoofers are and why they’re so crucial for audio enthusiasts? Let’s delve into the fascinating world of subwoofers so you can discover their purpose, function, and ultimately how a subwoofer works.

What Are Subwoofers?

Pioneer TS-WX1210A 12-inch Sealed Enclosure Subwoofer

Subwoofers are specialized speakers crafted to deliver powerful, low-frequency sounds, also known as bass. These sounds are essential to creating a complete, captivating audio experience, but they are often missing from smaller speakers such as those found in most computers, televisions, and smartphones.

A subwoofer is an essential piece of the audio puzzle, adding the finishing touch to your listening experience. It excels at reproducing low-frequency sounds that fall between 20 – 200 Hz, frequencies that other audio setups simply can’t handle.

The addition of a subwoofer to your sound system, whether it be a 2-channel or 7.1 surround sound setup, elevates your audio experience by providing the deep, rich bass tones that complete the soundscape.

The subwoofer functions in perfect harmony with the rest of your audio components, ensuring that not a single beat is missed and that the full audio spectrum is brought to life. Whether it’s the explosive boom of an action movie or the thundering bass energy of your favorite music, a subwoofer brings a new dimension of sound to your entertainment system.

How Subwoofers Function?

A subwoofer transforms electrical signals into mechanical energy, producing thick sound waves. The woofer cones, also referred to as the diaphragm, vibrate back and forth to create deeper bass frequencies controlled by the voice coil and magnet.

A subwoofer speaker is a specialized audio component that delivers powerful, and deep bass tones. This is achieved through the use of large woofers housed within a wooden or plastic casing that work in tandem with a built-in amplifier to produce a rich and detailed soundscape.

But the pursuit of high-quality sound requires more than just big drivers and amplifiers. The subwoofer must also navigate two critical components of audio playback: crossover and phasing.

Crossover is the point at which the subwoofer takes over from the main speakers, handling the lower frequency notes. To get the best results from your subwoofer, it is recommended to set the crossover frequency at 10Hz above your speaker’s lowest frequency range.

Phasing refers to the timing differences between two identical signals, and it’s crucial for the woofers to move in sync for optimal performance. If the woofers are out of phase, the bass will cancel out, and the sound will be negatively impacted. This can be resolved by using a 0/180-degree phase switch, which helps “dial in” your subwoofer for the best possible sound.

Why Are Subwoofers A Must-Have?

Subwoofers are indispensable for an immersive audio experience, filling in the lower frequencies that other speakers cannot produce. Without subwoofers, your music, movies, and games will sound lackluster and unfulfilling.

Moreover, subwoofers offer you control over bass levels, allowing you to customize your audio experience to your liking. With a high-quality subwoofer, you can feel the pounding of a bass drum or the earth-shaking rumble of an explosion, elevating your audio experience to new heights.

The kick drums and the bass guitar are among the most important instruments in modern music. These instruments provide the beat, energy, and rhythm of a song. Guess what? The sound reproduced by these instruments is located in the lower frequency range. It can be hard to hear the depth and clarity of these instruments in a song without a subwoofer.

Choosing The Ideal Subwoofer For Bass Frequencies

When selecting a subwoofer, several factors should be taken into account. Firstly, the subwoofer’s size should match the size of your room. Smaller rooms require smaller subwoofers, while larger rooms require larger subwoofers to produce similar sound levels.

Additionally, you’ll need to decide between powered and passive subwoofers. Powered subwoofers have an integrated amplifier and are easy to set up, while passive subs need an external amp.

The subwoofer’s frequency response range is also important. Plus, this range indicates the frequencies that the subwoofer can accurately reproduce. The wider the frequency response range, the better the subwoofer will be at producing low frequencies.

Types of Subwoofers For Your Sound System

If a car has two subwoofers, they are most likely passive subs that require an amp to power. Other models that go under the seat typically come with a built-in amp that amplifies the signal from the head unit, making it possible to reproduce low frequencies. Let’s go over the differences:

Active subwoofers

An active subwoofer is a type of subwoofer that contains a built-in amplifier. Unlike passive subwoofers, active subwoofers don’t require an external amplifier to power the subwoofer speaker. Instead, the subwoofer contains its own amplifier, allowing for a simpler and more compact design.

The built-in amplifier also provides greater control over the subwoofer’s performance, allowing for easy adjustments to the volume and tone of the low-frequency sound. These subwoofers are often favored by home theater enthusiasts and audiophiles as they provide a more convenient and efficient solution for adding deep, powerful bass to their audio setups.

Passive subwoofers

A passive subwoofer is a type of subwoofer that doesn’t have a built-in amplifier. Instead, they rely on an external amplifier to power the speaker and produce sound. Passive subwoofers typically consist of only the subwoofer driver, housed within a wooden or plastic enclosure, and are connected to an external amp via speaker wire.

A passive speaker can offer a few advantages over active subwoofers. Firstly, they offer more flexibility in terms of amplifier choice, as the user can select an amplifier that best suits their needs and preferences. Additionally, they are often easier to upgrade, as the user can simply replace the subwoofer driver rather than the entire unit.

They are favored by some audiophiles and home theater enthusiasts due to the greater control and customization they provide. However, they require a separate amplifier and may require additional wiring and setup, making them less convenient for some users.

Horn-loaded subwoofers

Horn-loaded subwoofers are a type of bass-frequency speaker system that uses a horn to increase the efficiency and directional control of low-frequency sound waves. They work by using the horn to collect and amplify the output from the speaker driver, directing it toward the listener for improved projection and power.

This design can produce very high levels of low-frequency output with minimal distortion and allows for more compact subwoofer designs compared to other types of front-firing subwoofers. Horn-loaded subwoofers are often used in professional sound reinforcement systems, home theater systems, and high-end audio systems.

Sealed vs. Ported Subwoofers

Different set of subwoofers with louder preamp

Ported subwoofers are a type of subwoofer that uses a vent or port to increase the volume of low-frequency sound they can produce. The port, which is a hole in the subwoofer enclosure, allows air to move in and out of the enclosure, which enhances the subwoofer’s performance.

Ported subs have several benefits over sealed subwoofers, which are subwoofers that don’t use a port. For example, ported subwoofers can typically produce deeper and more powerful bass because the port allows the subwoofer to move more air.

Additionally, because the port helps to lower the subwoofer’s resonant frequency, it can produce cleaner and more defined bass. This is great when it comes to reproducing movie sound effects and bass-heavy music. The bass response of these subs can cover a wider range in the frequency spectrum.

However, ported subs also have some disadvantages. For example, they can be more sensitive to room placement and require more careful setup to achieve optimal sound. Additionally, they can be less accurate than sealed subwoofers, as the port can introduce distortions and other anomalies in the subwoofer’s output.

Overall, whether a ported or sealed subwoofer is, the better choice depends on the specific requirements and preferences of the user. Both types of subwoofers have their pros and cons, and the right choice will depend on the user’s needs, room size, and other factors.

Where Can You Place A Subwoofer To Produce a Deep Bass?

In any speaker setup, placement plays a key role in the overall sound quality. To achieve the best sound, it’s important to consider the room and its acoustic properties.

If you have a dedicated home theater or listening room, finding the optimal speaker placement should be relatively straightforward. However, if you don’t have a dedicated space, you may need to rearrange the room to create the ideal setup.

One approach is to start by placing your speakers in corners with sound-absorbing materials, such as filled bookshelves or acoustic panels, and then experiment with different positions. If you’re experiencing “boomy” or undefined bass, it could be due to standing waves in the room, and if you notice dead spots in the sound, you may be encountering bass nulls.

For even better sound, consider investing in acoustic treatments, such as acoustic panels, diffusers, and bass traps. Another option is to look for an A/V receiver with room-correction technology, such as Audyssey or AccuEQ, which can automatically calibrate each speaker for optimal sound in your specific room.

In Conclusion

Most surround sound systems need a sub-bass so that they can reproduce both high and low frequencies. High-range frequencies are covered by the mid-range speaker system, and the bass sounds are reproduced by the subwoofer system.

Subwoofers are the key to unlocking a world of immersive sound, filling in the lower frequencies that other speakers can’t deliver. Once you have installed a sub, you can say that you have a complete audio system.

By choosing the right subwoofer for your room and audio preferences, you’ll be able to enjoy your favorite movies, music, and games like never before. So, take the leap and invest in a top-notch subwoofer today and transform your audio experience!

Last Updated on: February 2, 2023

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