Everything you need to know about home theatre subwoofers

October 27, 2017
Everything you need to know about home theatre subwoofers
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 Amazing images on a large projector screen and an immersive surround sound are what captivate you as an audience in a movie theatre. One of the things that really grabs you is the sound you actually feel; the deep bass that shakes you up and gets you right in the gut. A specialized speaker, known as a subwoofer is responsible for this experience. The subwoofer is designed only to reproduce the lowest of audible frequencies. Subwoofers are crucial to the home theatre experience.

In home theatre, this is often referred to as LFE (Low-Frequency Effects). Today’s surround sound home theatre systems have dedicated speakers for centre channel dialogues, main soundtracks, surround, and even height effects such as Dolby Atmos, the need for a speaker to reproduce the lower frequencies of a movie soundtrack is all the more crucial. The surround sound channel that is dedicated to the subwoofer is referred to as the .1 channel. Buying a subwoofer is a necessity when it comes to the home theatre experience.

Here, we share everything you need know about home theatre subwoofers.

What is a subwoofer?

All about home theatre subwoofers

A subwoofer or a sub is a loudspeaker which is dedicated to the reproduction of low-pitched audio frequencies known as bass. The frequency range of subwoofers is about 20–200 Hz for consumer products, below 100 Hz for professional PA & live sound, and below 80 Hz in THX-approved systems. They are made up of one or more low-frequency woofers mounted in an enclosure often made of wood that is capable of withstanding air pressure.

What are the types of home theatre subwoofer?

Passive Subwoofers

Passive subwoofers are powered by an external amplifier. As extreme bass frequencies need more power to reproduce low-frequency sounds, many users prefer driving the subwoofer via a dedicated amplifier. This reduces drain and on your AV receiver. The amount of depends on the requirements of the speaker system and the size of the room.

Powered Subwoofers

To solve the problem of inadequate power or other characteristics that receivers or amplifier may plack, powered or active subwoofers are self-contained speaker/amplifier units in which the characteristics of the amplifier and subwoofer are optimally matched. Many powered subwoofers also feature a host of DSP technologies to improve the overall tone and output. They easily connect via dedicated LFE inputs from the AV receiver. Just like their passive counterparts, they reduce the load and dependency of your receiver or amplifiers for the mid & high-frequency output.

Front-Firing and Down-Firing Subwoofers

Front-Firing and Down-Firing Subwoofers

  • Front-firing subwoofers use a speaker driver mounted so that it radiates the sound from the side or front of the subwoofer enclosure.
  • Down-firing subwoofers use a speaker that is mounted bottom-facing so that it radiates downward towards the floor.

Ports and Passive Radiators

Some subwoofer enclosures also employ an additional port, which forces out more air, increasing bass response in a more efficient manner than sealed enclosures. Another type of enclosure utilizes a Passive Radiator in addition to the speaker, instead of a port, to increase efficiency and preciseness. Passive Radiators can either be a speaker driver with the voice coil removed or a flat diaphragm. Instead of vibrating directly from the electrically transmitted audio signal, a passive radiator reacts to the air that is pushed by the active subwoofer driver. As the passive radiator complements the action of the active driver, it helps to increase the low-frequency response of the subwoofer.

What are wireless subwoofer?

A growing number of powered subwoofers offer wireless connectivity. This makes a lot of sense as powered subs have their own built-in amplifiers, and it eliminates the need for a long connection cable between the subwoofer and home theatre receiver. A wireless-enabled subwoofer usually comes with a transmitter kit that can be plugged into the subwoofer outputs of any home theatre receiver.


The crossover is an electronic circuit that routes all frequencies below a specific point to the subwoofer; all frequencies above that point are reproduced the main, centre, and surround speakers. Typically, a good subwoofer has a selectable crossover frequency.

We hope you now understand the awesome functionalities of subwoofers in your home theatre system. Use the comment section below to share your thoughts and inputs. Do follow our blog for more such tips, tricks, tutorials and other useful information.

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1 comment

Thanks a lot for sharing your incredible ideas. It is an appreciated and pretty tip for all those music lovers. What a Fatal post for those who want to upgrade exist subwoofer with new one.

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