How Do Subwoofers Work?
Years back, people thought subwoofers were rather special equipment only extreme hi-fi enthusiasts were interested in.
But things changed over times. Now subwoofers are considered the most significant part of modern sound system.
Subwoofers are indispensable hi-fi parts of any decent home theater system since they enrich your sound with the much needed “Boom”. They boom the thunder, the explosions, the rumbles and the deep lows enlivening your music.
Subwoofers work fine to get you the full taste of music and experience the real-life sounds.
And they are manufactured in a variety of designs to make your interior design even more beautiful.
In this article, we’re going to explain how subwoofers work and why you need one.
What a Subwoofer is?
In short, a subwoofer is a kind of speaker designed to reproduce very low bass frequencies ranging 20 Hz (sometimes less) and 125 Hz. You can feel the sounds as much you hear them at these low bass frequencies.
People use subwoofers to get the powerful audio punches and rumbles usually found in music videos or movies, especially dramatic effects relating to explosions and crashes.
2.1, 5.1 And .1
Do you know why speakers are labeled 2.1 or 5.1?
2.1 means two speakers come with a subwoofer. Similarly, five speakers with a sub mean 5.1.
The subwoofer technically doesn’t count to be a whole speaker, so it’s referred to as .1, since it doesn’t put out the same frequency rang as the other speakers.
Subwoofer speakers are manufactured relatively larger in size, between 8 inches and 15 inches in diameter, and found in enclosures of different sizes. With a longer throw (the distance a speaker can be moved back and forth), a larger speaker diameter cuts high frequency response.
A subwoofer could occupy quite a bit of space in your listening room because of its large speaker diameter and the enclosure / box that matches it.
Lows, Mids & Highs
You’ll need to understand the basic nature of sound to know how the subs work. There’re three layers of sound- lows, mids and highs.
The low frequency bass notes like the beat of a bass drum. Middle frequency sounds like a singer’s voice, a guitar. Highs are the higher frequency sounds like certain nuances of guitars and other instruments or ringing or clashing sounds.
Subwoofers put out these low frequency sounds; they produce clearer, better bass than what regular speakers deliver. It’s specially designed for producing low frequency sounds/bass.
Sub reduces the strain on the speaker capability of producing the highs, mids and lows; without it, the sounds get cluttered.
You should get a subwoofer with the other components of your system to make it reproduce bass as the rest of the speakers manage the mids and highs.
Types of Subwoofer
There’re two types of subwoofer- passive and active.
Each of them comes with some advantages and disadvantages. Let’s discuss in detail.
A passive subwoofer is a woofer in an enclosure driven by an external amplifier. In a kind of the passive sub, the same stereo amplifier that drives the main speakers provides power to the sub. The full-range output from a power amp is input to the sub in this method.
In this case, an extra crossover in the signal path is used to remove bass from the speaker-level signals driving the main speakers. Moreover, the crossover isn’t used in some subwoofers that extend bass response without filtering bass from the signal driving to the main speaker; thereby it doesn’t boost up the power handling of the main speakers.
If you want to employ a passive sub, we suggest that you add a separate power amp and an electronic crossover to the sub. Because it’ll enhance your system’s dynamic range, keeping the main speaker amplifier free from the load of driving the sub.
A powered subwoofer is a woofer in a cabinet with its own amplifier/preamp and a line-level crossover. This subwoofer has line-level inputs fed from the preamp, line-level outputs driving the power amp, and a volume control.
The crossover frequency can be adjusted to let you select the frequency, providing the best integration with the main speakers; and the line-level output is filtered by removing low frequencies from the signal. The amplifier drives the woofer and the preamplifier does a host of useful tasks.
Designs of Subwoofer
Subwoofers come with three designs- sealed, ported, and isobaric box designs.
Sealed box subwoofers are the most basic and cleanest sub box design. Isolating the back of the speaker from the front, the sealed box provides simple construction and controlled response for the most of subwoofer applications.
You’ll get a tight, well-defined bass if it’s well manufactured.
Ported box subwoofers have a hole in them, which is called a port. A ported subwoofer can produce lower bass tones per watt input than a non-ported sub.
The port / vent of it increases output at certain frequencies. Building this type of box is much complicated. We suggest that you comply with the specifications of the speaker’s manual to optimize the output and prevent damage to speaker.
Isobaric box subwoofers are designed to get the maximum bass from a very small space. It’s a unique kind of box where two woofers are used and coupled together to work as a single woofer with twice as much pushing power.
This sub’s major pro is its size, for the enclosure requirement for this design is half the size of the sealed box for the speaker- which means you’ll have great bass from a very small space.
But you’ll need to purchase double the number of speakers and power each one as though it were playing by itself. So, you require double the power and get overall output as same as from a single speaker.
Isobaric box also comes in varieties like cone to cone, cone to magnet, and magnet to magnet.
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Deflection of Bass
For your home theater system, you can hide the subwoofer from view by setting it in a corner where the bass can deflect off a wall. One of the interesting things of a subwoofer is that the sound works best as it deflects off something.
When the sub is on, you can’t exactly say where it’s placed or where the bass travels from. So, the sound isn’t as directional as regular speaker. It’s specially designed to trick your ears.
If your subwoofer and other speakers are on, the sub anywhere in your listening room seems to sound like the other speakers producing the bass whereas the sub’s putting out those low frequencies from one corner.
Lastly, we want to conclude that adding a subwoofer to any stereo system makes an incredible difference by making you hear the sounds you’ve never heard before, since regular speakers can’t produce them.
So, rediscover your favorite music all over again with a subwoofer, allowing your sound system to sound differently.
Let us know how much the subwoofers help you enjoy music, movies and video games?
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