Subwoofer

A sub is a loud speaker.

It makes very deep sounds. It makes sounds like big drums or thunder.

It helps you hear the lowest notes. These notes come from a tuba or a piano.

It works with other speakers. The other speakers play the high sounds.

This makes the music sound great. It is fun to hear!

A subwoofer is a special type of loudspeaker.

It is made to play very low sounds. We call these sounds bass or sub-bass. These notes are much lower than what regular speakers make. Subwoofers help you hear the deep tones of a tuba. They also make the sound of thunder or a big drum.

Subwoofers do not work alone. They work with main speakers. A crossover network helps them work together. This tool sends low sounds to the subwoofer. It sends high sounds to the main speakers. This keeps the sound clear.

Most subwoofers live in a wooden box. This box is called an enclosure. The box helps the sound stay strong. Some subwoofers are active. This means they have a built-in amplifier to give them power. Others are passive. These need an outside amplifier to work. In the 1970s, movies used large subwoofers. They made loud rumbling sounds for films like Earthquake. Today, you can find them in cars and clubs.

A subwoofer is a special kind of loudspeaker. It is made to play very low sounds. We call these sounds bass or sub-bass. These notes are lower than what regular speakers can play. Subwoofers are very important for high-quality sound. They handle the lowest parts of the music we hear.

These deep sounds include the tones of a tuba or a bass drum. They also make the sound of thunder or a big explosion. Without them, these sounds might not feel as strong.

Subwoofers do not work by themselves. They work with main speakers to make a full sound. A crossover network is used to split the sound. This network sends low signals to the subwoofer. It sends higher signals to the main speakers. This way, each speaker does its best job.

Some subwoofers are active. This means they have a built-in amplifier to provide power. Other subwoofers are passive. These need an outside amplifier to work.

People have been working on deep sound for a long time. In 1933, Douglas Shearer worked with John Hilliard and James B. Lansing. They made a speaker system for movie theaters. This system used a special bass horn. Later, in 1964, Raymon Dones received a patent for a subwoofer. He called his invention "The Octavium."

It could play very low sounds without people knowing where they came from. This helped musicians like the Grateful Dead hear deep bass clearly.

There are many ways to build a subwoofer box. These boxes are called enclosures. They are often made of wood. Some designs use a vent, which is called a bass reflex design.

Other designs are sealed tight. Some use a special shape called a horn. These different designs change how loud or efficient the speaker is.

In the 1970s, movies like "Earthquake" used a system called Sensurround. It used large subwoofers to make loud rumbling sounds in theaters. These sounds reached 110 to 120 decibels.

You can find subwoofers in many places today. Many people use them in home theater systems to watch movies. You might also find them in cars or in big nightclubs.

They help make music feel more lifelike. When you hear a deep drum, the subwoofer is likely helping. It connects the music to the physical feeling of the sound. This makes listening to music a much more exciting experience.

A subwoofer is a specialized loudspeaker designed to reproduce low-pitched audio frequencies. These frequencies are known as bass and sub-bass. They are lower than the sounds a standard woofer can optimally generate. Subwoofers are vital for high-quality sound reproduction. They handle the lowest two to three octaves of the ten octaves that humans can hear. This very low-frequency (VLF) range reproduces the natural fundamental tones of instruments like the tuba, grand piano, and double bass. It also reproduces environmental sounds such as thunder, gunshots, and explosions.

Subwoofers are never used alone in a sound system. Instead, they work alongside "main" loudspeakers that cover higher frequency bands. To make this work, a crossover network is used. This network uses electronics, such as digital signal processing (DSP), to partition the audio. It sends VLF signals to the subwoofer and higher-frequency signals to the main speakers. Additionally, subwoofers often receive low-frequency effects (LFE) signals. These specific signals are reproduced at 10 dB higher than the standard peak level. This ensures the deepest effects are powerful and clear.

There are two main types of subwoofers: active and passive. An active subwoofer includes a built-in amplifier to provide its own power. A passive subwoofer has a driver and an enclosure but requires an external amplifier to function. The term "subwoofer" can refer strictly to the driver itself. However, in common use, it often refers to the driver mounted inside a speaker enclosure. These enclosures are often made of wood to withstand air pressure and resist deformation.

Engineers use many different enclosure designs to change how a subwoofer performs. Each design involves trade-offs in efficiency, loudness, cabinet size, and cost. A bass reflex design uses a port or vent to move air. Some designs use passive radiator speakers within the enclosure. Other types include acoustic suspension, which is a sealed enclosure. More complex designs include horn-loaded, tapped horn, transmission line, bandpass, and isobaric designs.

The history of deep sound began with early movie theater experiments. From 1900 to the 1950s, recordings rarely used frequencies below 100 Hz. In 1933, Douglas Shearer worked with John Hilliard and James B. Lansing. They developed the Shearing-Lansing 500-A, a two-way enclosure using a W-shaped bass horn. This system could reach frequencies as low as 30 Hz. In 1964, Raymon Dones received a patent for a subwoofer called "The Octavium." It could reproduce distortion-free sound down to 15 Hz.

Subwoofers became very famous in the 1970s due to the movie "Earthquake." This film used a system called Sensurround. It utilized large subwoofers driven by racks of 500-watt amplifiers. These subwoofers produced loud rumbling between 17 and 120 Hz. The sound pressure level reached 110 to 120 decibels (dB SPL). This technology helped the film become a massive box office success. By the 1990s, DVDs introduced a dedicated LFE channel for home-cinema systems.

Positioning a subwoofer is different than positioning main speakers. Because very low frequencies are nearly omnidirectional, their direction is hard to determine. This allows subwoofers to be placed more favorably within a room's acoustics. However, some audiophiles find them difficult to use. They often complain about the difficulty of "splicing" the subwoofer sound with the main speakers. This is because the driver can produce distortion above the crossover frequency. This distortion can interfere with the stereo image that human hearing can localize.

Today, subwoofers are found in almost every modern audio environment. They are used in high-end home stereo systems and custom car audio installations. They are also essential in professional PA systems. By the 2000s, they became nearly universal in nightclubs and concert venues. From the massive arrays in a stadium to small units for a computer, subwoofers provide the foundation of sound. They allow us to feel the physical impact of the lowest notes in our music.