Different Subwoofer Enclosures Provide Diverse Sound Experiences
Subwoofers can add a bass sound and a heart pounding bump to a car stereo system. Finding a perfect subwoofer is not the only thing that makes the sound spectacular. Matching a subwoofer with a suitable enclosure box can create varying sounds for a car's surround system. A strong, tightly constructed enclosure provides optimum subwoofer performance. The full bass will not be delivered if there is not a proper enclosure for the subwoofer. The sound from the back of the speaker can cancel out low frequencies emanating from the front.
People can try to construct their own boxes. However, a solid understanding of enclosure volumes and technical sound engineering is needed. Most people who are upgrading their car audio system are better off getting a pre-made subwoofer enclosure. Sealed box subwoofers are airtight and the best for any music that needs a tight and accurate bass. There will be a flat response, deep bass extension, and superior power handling. They provide a precise, clean sound and can fit in most places. Sealed enclosures require more power, so an amplifier with ample wattage will generate optimum performance.
Ported boxes utilize a vent to reinforce low bass response. More output is generated than from a sealed box at any amplifier wattage. Ported boxes are preferred for the sound of rock, heavy metal, or any other kind of hard driving music. Less power is needed and more boom is created, yet it is harder to tune. A subsonic filter on the amp will help generate cleaner tones. A deeper bass is delivered over sealed boxes but they need to be much larger in order to accomplish this sound.
Bandpass boxes provide the maximum amount of slam in subwoofers. They are a special type of ported box where the woofer is mounted inside a dual-chambered box. One chamber is sealed and the other is ported. Sound waves emerge from the ported side. Sound that comes out of the port is extra loud with a narrow frequency range. A bandpass box is very efficient within that range and tend to boom. They are louder at specifically tuned ranges of frequencies. The aggressive sound supplied by a bandpass box is perfect for rap, reggae, and hard rock. Not all subwoofers work well in bandpass boxes. Specifications for both the subwoofer and the bandpass box need to be compared.
Free-air subwoofer systems consist of subwoofers mounted to a board attached to the rear deck. They can also be placed in the trunk against the rear seat. The trunk acts as an enclosure to house the subwoofer and isolate sound from the back of the speaker, solving sound cancellation problems in subwoofers without getting an enclosure that takes up extra room. Free-air systems save space in the car and have a flat frequency response. However, the subwoofer must be specifically designed for free-air use. Lack of a box makes them more convenient to install. Power handling levels are lower than boxed counterparts.
A good bass sound makes or breaks the stereo experience. Audio will have depth and realism when a subwoofer and proper enclosure are installed. The factory installed subwoofers are usually too small to optimally handle low frequency sounds. Subwoofers come in a variety of sizes from eight inches to fifteeen inches. Component subwoofers come as speakers only. An enclosure and amplifier must be chosen separately. Some of the above enclosures work well with any subwoofer, but some enclosures also need to be custom made. Component subwoofers are perfect for drivers who want to build a highly customizes stereo system for their car.
Powered subwoofers include the speaker and the amp in one compact enclosure. These are ideal for installing in small spaces. Vehicle specific subwoofers are designed to fit in spaces that are out of the way in order to save space. A good example is a subwoofer located in the door. It is perfect for a discreet install. Neither powered or specific subwoofers have a big bass sound.
Sources: http://www.halfpricecaraudio.com/Subwoofer-Boxes.htm http://ezinearticles.com/?Different-Subwoofer-Enclosures-ProvideDiverse-Sound-Experiences&id=8083504