A subwoofer (the “bass”) is a specialized speaker designed to reproduce the lowest of audible frequencies.
With the popularity of home theatre sound systems, subwoofers are becoming more and more crucial to the home theater experience to reproduce the deep bass portions of a movie soundtrack.
Subwoofers come in two basic types, passive and powered. Passive subwoofers are powered by an external amplifier, in the same way other speakers in your system are powered. The amount of power needed depeneds on the requirements of the speaker and the size of the room. Powered subwoofers, on the other hand, are self-contained speaker/amplifier configurations and the characteristics of the amplifier and the subwoofer are optimally matched.
Additional subwoofer design variations include front-firing, down-firing and the use of ports or passive radiators. Front-firing subwoofers use a mounted speaker so that it radiates the sound from the side or front of the subwoofer enclosure. Down-firing subwoofers use a mounted speaker so that sound radiates downward, towards the floor. It’s important to note that if you live in an upstairs apartment, a down-firing subwoofer may disturb your downstairs neighbors more easily that a front-firing design. Other types of enclosures use a passive radiator in addition to the speaker to increase efficiency and preciseness. Passive radiators can either be speakers with the voice coil removed or a flat diaphragm.
While the technical specifications and design factors of subwoofers are important, the type of subwoofer for your system ultimately depends on the characteristics of your room and your preferences. It’s a good idea to take a favourite DVD and/or CD with a lot of bass when you go see a dealer and to listen to how the bass sounds through various subwoofers.
You should also ask about the return policy just in case you buy a subwoofer that doesn’t perform well in your listening environment. Place the subwoofer in various sections of the room to find out what sounds most pleasing. The subwoofer shouldn’t sound boomy, but rather deep and tight.