A laptop subwoofer is a speaker used on a laptop computer to create low frequency sounds. There are two main types of subwoofers that can be used with laptops, those that are built into the computer and those that can be plugged into them when listening to audio. The size of a laptop computer makes it difficult to fit a quality subwoofer into it, so built-in laptop subwoofers may not produce low-end sounds that are of good quality. Plug-in subwoofers are often large and not particularly portable, but they can be used at home to give the laptop a better sound system.
Subwoofers are very similar to other speakers in both their function and design. They produce sound by creating a vibrating surface that forces sound waves into a room. The subwoofer differs from other types of speakers in that it produces sound that is only below a frequency of 200 hertz, which is about the middle of the range of the human voice. A laptop subwoofer will produce these low-end sounds just as any other type of subwoofer would. The sounds that are a higher frequency will be produced by the other speakers on the laptop.
In some cases, a laptop subwoofer is built into the computer. If it is, it will be visible from the outside of the case and situated on the bottom. This type of laptop subwoofer looks like a small disk and is usually no larger than 1 inch (2.5 centimeters) in diameter because there is not enough space inside the compact frame of a laptop for a larger subwoofer.
A built-in laptop subwoofer will be limited in function. Regular subwoofers are usually at least a few inches (10 or so centimeters) deep to allow the subwoofer enough space to produce high quality low-frequency sound. Low-end sound produced by a subwoofer that is less than 1 inch (2.5 centimeters) deep will not be high quality.
In order to produce high-quality low-frequency sound, an external laptop subwoofer needs to be used. These devices are usually attached to a pair of external speakers and plug into the laptop through an audio jack, a universal serial bus (USB), or a firewire bus. These laptop subwoofers are often bulky and are not designed to be carried around along with the laptop. If a person frequently uses the laptop at home or at work, however, an external speaker system that includes a subwoofer can be plugged into the laptop whenever needed.