In a previous article, we talked about Tweeters. This time, let’s get into woofers. When you’re buying a new home theater system or sound bar, or even when looking for a new car, you have likely heard the words: tweeter, woofer, subwoofer, and midranges without really knowing what that means.
Every sound you hear has a given frequency. Typically, the human hearing range is from 20 Hz to 20,000 Hz, which you may think is a vast range, and indeed it is. That’s why there are several types of speakers. A Woofer is designed to reproduce low-frequency sounds, typically from around 50 Hz to 1,000 Hz (50 Hz to 1KHz).
How do speakers work?
Traditional speakers produce sound using an electromagnet to move a flexible cone back and forth. They use drivers to help translate electrical signals into physical vibrations so that you can hear recorded sounds. A woofer is one of the three main speaker types.
Why are woofers important?
Woofers and subwoofers are essential because the low frequencies also help produce the full, rich, three-dimensional effect we love in movie soundtracks and music. Without a woofer/subwoofer, you’ll miss out on some of the explosions and gunshots for movies and video games. Music-wise, you will partially miss instruments like the bass, tuba, and trombone.
Wait! What is a woofer, and is it different from a subwoofer?
Woofers and subwoofers reproduce low frequencies, but their work frequency range is the main difference. A woofer has frequency ranges of between 20Hz to 2KHz, while a subwoofer can only cover a much narrower frequency range of 20Hz to 200Hz.
In short words, a woofer is a specialized speaker; and a subwoofer is a specialized woofer covering a narrow frequency range. Some examples where a subwoofer is useful are reproducing specific low-frequency effects (LFE), such as earthquakes and explosions in movies, and for music, pipe organ pedal notes, acoustic double bass, and tympani.
How can I tell apart a woofer?
Pretty easy. The key is the size:
- Tweeter: The smallest of all.
- Midrange: They are….well, mid-size.
- Woofer: They are noticeably bigger.
- Subwoofer: Even bigger and likely to find multiple woofers within a large speaker enclosure.
Why are woofers bigger than tweeters?
The lower the frequency, the longer the sound wave. This means drivers need to work harder to produce low frequencies in volumes you can hear, which is why woofer drivers tend to be much bigger than midrange or tweeters (high-frequency drivers): the bigger the driver, the easier it is to produce the long-wave frequencies.
The larger size allows the driver to move much air while maintaining the required low frequency.
Which is the typical size of a woofer?
A woofer can be as small as 4 inches in diameter or as large as 15 inches. Woofers with 6.5-inch to 8-inch diameters are standard in floor-standing speakers. Bookshelf speakers typically have woofers with diameters in the 4-inch and 5-inch range. Here’s how to measure a speaker’s size if you want to learn.
What happens if a woofer reproduces high frequencies?
Not much happens. Most modern sound systems include filters (also called crossovers) that will block any sound out of your woofer’s frequency range.
Materials used in woofers
It is usually the cone material used in most speaker marketing materials to get you to buy speakers. The three chief properties designers look for in cones are lightweight, stiffness, and lack of coloration (unwanted resonances).
Below are some of the most common materials used for woofers:
- Paper: Mistakenly believed that paper is an old fashion way to build a speaker. Sensitive to temperature and humidity.
- “Doped paper: A layer of plastic or other material to protect paper from the environment. Also, it makes paper cones more “stable and rigid” Doped paper: A layer of plastic or other material to protect paper from the environment. Also, it makes paper cones more”stable” and rigid.” Doped paper: A layer of plastic or other material to protect paper from the environment. Also, it makes paper cones more “stable” and rigid.” Doped paper: A layer of plastic or other material to protect paper from the environment. Also, it makes paper cones more “stable” and rigid.
- Polypropylene is the most common material used in today’s speaker manufacture.
- Kevlar: It’s light and stiff but can have coloration problems. It needs to be carefully constructed and built.
- Metals (Magnesium): Similar to kevlar, metals can produce great low-end sound but also bring coloration issues if not well-designed
Other materials could include injection-molded graphite (IMG) and glass fiber. There are hundreds of subcategories under each as speaker manufacturers try to differentiate their speakers and make them unique.
Then, which is the best material for woofers?
¡All of them! And none at the same time. So many factors contribute to a great woofer, not just the material. A well-designed paper woofer could outperform a poorly designed Kevlar woofer which looks nicer and costs twice.
Some of the factors that matter for overall woofer performance are:
- The cabinet
- The crossover (filter)
- Ported or not ported (a hole in the front/back of the speaker cabinet)
- Your listening environment (room layout)
Anything else to know about woofers?
“Of course! Woofers could be called bass speakers. Additionally, the name is from the onomatopoeic English word for a dog’s bark,” woof” Of course! Woofers could be called bass speakers. Additionally, the name is from the onomatopoeic English word for a dog’s bark, “woof.” Of course! Woofers could be called bass speakers. Additionally, the name is from the onomatopoeic English word for a dog’s bark, “woof.” Of course! Woofers could be called bass speakers. Additionally, the name is from the onomatopoeic English word for a dog’s bark, “woof.”
Remember that any speaker will sound completely different in your home than in the store. A good advice is to listen to music you know well to get your first impressions.
What is the difference between powered subwoofers and traditional speakers?
Powered subwoofers and traditional speakers differ in multiple aspects. One significant distinction is that most subwoofers are powered, meaning they have a built-in amplifier. Unlike traditional speakers, which require an external amplifier to supply power, powered subwoofers can operate independently. This eliminates the need for additional equipment and simplifies the setup process.
In terms of sound reproduction, another difference lies in the frequency range. Traditional speakers typically cover a wide range of frequencies, including mid-range and high frequencies. On the other hand, subwoofers are specifically designed to reproduce low-frequency sounds, such as bass. Their focused purpose allows them to excel at producing deep, rumbling tones that traditional speakers might not be able to reproduce as effectively.
Additionally, the construction and design of powered subwoofers often differ from traditional speakers. Subwoofers are often larger and heavier due to the added built-in amplifier and specialized components required to handle low-frequency sounds. The size and weight can impact their placement and installation, as they may require a more stable support system compared to standard speakers. Traditional speakers, being more compact and lightweight, offer greater flexibility in terms of placement and positioning.
Finally, powered subwoofers are commonly utilized in home theater setups and professional audio systems to enhance the overall sound experience. By adding a powerful low-end bass foundation, subwoofers create a more immersive and impactful audio environment. Traditional speakers, on the other hand, are versatile and can be used in various applications, including music playback, multimedia, and general purpose audio.
In summary, the main differences between powered subwoofers and traditional speakers lie in the presence of a built-in amplifier in subwoofers, their specialization in reproducing low-frequency sounds, their construction, placement requirements, and their respective applications in audio systems.
What are bass reflex speakers?
Bass reflex speakers, also known as ported speakers, are a type of speaker design that incorporates a port, which is a tube placed on the front or rear of the speaker enclosure. The purpose of this port is to enhance the low-frequency output of the speaker by utilizing the air pumped out by the woofer.
Unlike passive radiators that rely on a passive diaphragm to enhance bass response, bass reflex speakers use the port to achieve a similar effect. The port allows the air generated by the woofer to be directed through it, resulting in a complementary low-frequency reinforcement.
To achieve optimal performance, the port must be carefully designed with a specific diameter and tuned to match the characteristics of the speaker enclosure and woofer it complements. This tuning ensures that the port resonates at the correct frequency, maximizing the efficiency and effectiveness of the bass response.
Speakers equipped with a port, or bass reflex design, are commonly referred to as bass reflex speakers. These speakers offer advantages such as enhanced low-frequency extension, improved efficiency, and the ability to produce a more powerful and dynamic bass output compared to other speaker designs.
What is an alternative to a passive radiator?
An alternative to a passive radiator is a feature known as a port. Ports are tubes that can be positioned on either the front or back of a speaker enclosure. These tubes allow the air pushed out by the woofer to be directed through the port, resulting in a similar enhancement to the low-frequency response as achieved with a passive radiator. However, unlike a passive radiator, a port needs to have a specific diameter and be precisely tuned to match the characteristics of the enclosure and the woofer it complements. Speaker systems that incorporate a port are often referred to as bass reflex speakers.
How does a passive radiator enhance bass output in smaller speaker cabinets?
A passive radiator is an essential component that enhances bass output in smaller speaker cabinets. While it may not provide the exact same performance as two woofers connected directly to the amplifier, the combination of a main woofer and a passive radiator results in more effective bass production. This setup is particularly well-suited for smaller speaker cabinets, as it offers specific advantages.
Firstly, the main woofer is positioned to face outward towards the listening area. This enables it to efficiently emit sound waves directly to the listener, ensuring optimal sound projection and clarity. Secondly, the passive radiator is strategically placed on the back of the speaker enclosure. This positioning allows the passive radiator to function effectively without being hindered by the limited space available.
When sound waves are emitted by the main woofer, they cause the passive radiator to vibrate in response. As a result, the passive radiator functions as an additional source of bass output, amplifying the overall low-frequency response of the speaker system. By vibrating in sync with the main woofer, the passive radiator complements and reinforces the bass frequencies, creating a more robust and impactful bass experience for the listener.
In summary, the inclusion of a passive radiator in smaller speaker cabinets is a clever solution to enhance bass output. By utilizing the main woofer to directly project sound towards the listener and strategically placing the passive radiator on the rear of the enclosure, the combined setup effectively boosts the low-frequency response, producing richer and more powerful bass in a compact speaker design.
What is a passive radiator and how does it work?
A passive radiator is a component commonly found in speaker systems that operates similarly to a regular speaker. However, it does not have a voice coil like a typical speaker. Instead, it utilizes the movement of air generated by the main woofer inside the speaker enclosure to vibrate its diaphragm, surround, spider, and frame.
The passive radiator essentially works in tandem with the woofer to enhance the bass output of the speaker. When the woofer pushes air inside the enclosure, the passive radiator responds by vibrating at the same frequency and amplitude. This synchronized movement results in a complementary effect, where the energy provided by the woofer powers both itself and the passive radiator.
Though not identical to having two woofers connected directly to the amplifier, the combination of the woofer and passive radiator can produce more efficient and effective bass sound. This is especially advantageous in smaller speaker cabinets, as it allows the main woofer to face outward towards the listening area, while the passive radiator can be positioned on the back of the enclosure.
In summary, a passive radiator works by utilizing the air movement created by the woofer to vibrate and produce sound. By working in harmony with the woofer, it enhances the bass output of the speaker system and can be particularly advantageous when space is limited.
What are the components of a speaker?
A speaker is comprised of various components, each playing a crucial role in converting electrical signals into audible sound. These components include:
1. Frame or Basket: The speaker components are housed within a metal frame or basket. This structure provides support and protection to the internal components.
2. Diaphragm/Cone: The diaphragm, commonly referred to as the cone, is a crucial part that vibrates to produce sound waves. It pushes air outwards in a pattern that replicates the desired sound waves perceived by our ears.
3. Surround: The outer ring of the diaphragm, known as the surround, holds it in place within the frame. Usually made of rubber, foam, or other flexible materials, the surround allows the diaphragm to vibrate freely.
4. Spider: The spider is an additional support structure for the speaker. It helps to keep the voice coil and diaphragm aligned properly.
5. Voice Coil: Located at the back of the diaphragm, the voice coil is a coil of wire wrapped around an electromagnet. When an electrical signal passes through the coil, it interacts with the magnet to create a magnetic field that drives the diaphragm’s motion.
6. Dust Cap: In cone speakers, a dust cap is typically added to cover the area where the voice coil attaches to the diaphragm. This component protects the voice coil and diaphragm from any damage.
7. Enclosure: To ensure optimal performance and aesthetics, speakers are usually placed inside enclosures. These enclosures are commonly made of wood but can also be constructed from materials like plastic or aluminum. They help enhance the speaker’s overall sound reproduction by controlling sound waves and minimizing unwanted resonances.
It’s worth noting that not all speakers use a cone to produce sound. Some manufacturers incorporate alternative technologies such as horns, electrostatic panels, ribbon drivers, or non-traditional methods for sound reproduction. Despite the variations, these components remain essential for the operation of a speaker.
What is a loudspeaker and how does it work?
A loudspeaker is a device that converts electrical signals into audible sound through a process involving electromechanical components. It consists of various parts that work together to produce sound waves that can be heard by our ears.
At its core, a loudspeaker has a diaphragm, also known as a cone, which is responsible for pushing air and generating sound waves through its vibrations. The diaphragm is housed within a metal frame or basket that contains all the other components of the speaker.
To ensure that the diaphragm remains in place while still allowing flexibility for vibration, there is an outer ring made of rubber, foam, or a similar material called the surround. The surround holds the diaphragm securely and helps it vibrate freely.
Another crucial component is the spider, a supporting structure that prevents the diaphragm and surround from touching the outer metal frame. This ensures the smooth movement of the diaphragm and helps maintain the integrity of the speaker’s sound reproduction.
Located at the back of the diaphragm, there is a voice coil wrapped around an electromagnet. This voice coil and magnet assembly is responsible for providing the power necessary to cause the diaphragm to vibrate in response to electrical impulses received by the loudspeaker. When an electrical signal is sent through the voice coil, it interacts with the magnetic field created by the magnet, resulting in the movement of the diaphragm.
Additionally, the cone speaker typically has a dust cap, a small bulge that covers the area where the voice coil connects to the diaphragm. The dust cap protects the internal components of the speaker and helps maintain the overall performance of the loudspeaker.
In summary, a loudspeaker converts electrical signals into audible sound by utilizing a diaphragm that vibrates to produce sound waves. The diaphragm is supported by a surround and a spider, while a voice coil and magnet assembly provide the necessary power for the diaphragm’s movement. The resulting vibrations generate sound that can be heard by our ears.
What is the difference between full-range, woofers, tweeters, and mid-range speakers?
What is a mid-range speaker and why is it added to some enclosures?
A mid-range speaker is an additional speaker incorporated into some speaker enclosures to further separate the low-range and mid-range frequencies. While woofers are capable of reproducing low and mid-range frequencies, having a dedicated mid-range speaker allows for more precise and accurate reproduction of these frequencies. This enhances the overall sound quality and ensures a more balanced audio experience, particularly in reproducing the nuances of vocals and musical instruments within the mid-range frequency range.
What is the role of a tweeter in dispersing high-frequency sounds?
Tweeters are specially designed speakers that reproduce audio frequencies above a certain threshold, including sounds that human ears may not be able to hear but can sense. One of the main roles of a tweeter is to disperse high-frequency sounds into the room, ensuring accurate and balanced listening. Proper dispersion allows for a wider listening area, while avoiding dispersion that is too narrow or too wide, which can limit listening positions or cause a loss of directionality in sound perception.
What are the typical sizes of woofers and their common usage?
Woofers come in various sizes, with common diameters ranging from 4 inches to 15 inches. Woofers with diameters of 6.5 inches to 8 inches are commonly found in floor standing speakers, while those with diameters in the 4-inch and 5-inch range are often used in bookshelf speakers. The size of the woofer determines its ability to reproduce low and mid-range frequencies, making it suitable for reproducing voices, musical instruments, and sound effects.
What is the optimal frequency range for a speaker enclosure?
The optimal frequency range for a speaker enclosure is achieved by having speakers of different sizes inside the same enclosure. This allows for the reproduction of a wider range of frequencies, ensuring that both high and low frequencies are accurately reproduced.