If you love hard driving, heart pounding, deep resonate bass mixed with your music, you might enjoy owning a subwoofer. These compact sonic dynamos handle the lower ends of the audio frequency spectrum that other speakers may not. Contrary to what some may think, you don't have to wake the neighborhoods by cranking the volume on a subwoofer all the way up to max. Even when you listen at normal levels, a subwoofer lets you sense the solid beat of a bass drum coming from a symphony or the subtle thunderclap resonating in your favorite movie scene.
It's All About the Hertz
Take a seat in almost any modern movie theater that uses THX audio technology, and you'll probably hear and feel the hertz (Hz). Hertz refers to the number of cycles per second a sound wave vibrates. High frequencies produce brighter, breezier sounds while low frequencies produce bass. Low frequencies, coming from the bottom end of the sonic spectrum in the 50 to 500 Hz range, produce the bass sounds you hear in music, movie sound tracks and other recordings. Most people can hear sounds that lie between 20 and 20,000 Hz.
Some sounds don’t contain frequencies at the bottom end of the spectrum so it doesn't do any good to use a subwoofer to play them. Other general-purpose speakers in a sound system handle a wide range of frequencies and can reproduce them fairly well. For instance, if you watched a live performance of a flute orchestra, there would not be much bass for any speaker to deliver. Much of the entertainment world, however, consists of music, sound effects and other types of audio that do contain low bass frequencies that subwoofers can bring out. Most home theater systems and 5.1 A/V receivers dedicate a channel to those low frequencies. The "1" in the term "5.1" refers to that channel. The four other speakers in a 5.1 surround sound system handle the left and right stereo fields.
You can purchase two types of subwoofers: active and passive. Most consumers use active subwoofers because they have built-in amplifiers. Subwoofers need amplifiers and you'll find it more convenient to simply plug in a active subwoofer that already has an amp. Active subwoofers can produce excellent sound and have amplifiers that come in different power ratings. Gene DellaSala, president of Audioholics Online A/V, notes that a single subwoofer may produce distortion as it strains to generate sufficient output in rooms larger than it can handle. When considering a subwoofer, chat with a store representative, explain your room size and listen to floor room models that lie within your budget. If you have a larger area to fill with sound, the representative may recommend using two subwoofers. You’re always free to use an external amp to drive a passive subwoofer, but you don't have to go that route to achieve quality sound.
Placement and Crossover
Where you position a subwoofer is often as important as having one. After hooking up a subwoofer, try moving it to different parts of the room and listening to a song that has bass. Some areas of the room may not allow it to produce clear deep bass sounds as others because of acoustics, surrounding objects or phase interference caused by other speakers. Another way to achieve clearer, crisper sound is to adjust your subwoofer’s crossover frequency so its value is equal to the lowest frequency output by your other speakers. This ensures that your speakers don’t compete to reproduce the same low-frequency sounds and degrade audio quality. Your owner’s manual should show you how to perform this task.
The Polk Audio PSW10 subwoofer, a low-end alternative, according to CNET, "belts out tight home-theater bass and sounds sweet with music too." Housed in a sleek vinyl cabinet, the PSW10's internal amplifier cranks out 50 watts of power; this speaker is ideal if you have a small room or medium-sized room that you'd like to fill with high-quality audio. CNET lists the price for this subwoofer at $119 as of February 2012.
TopTenReviews gives the $499 BIC America Formula Series F-12 subwoofer a four-star rating. This 12-inch subwoofer mixes fashion with functionality by delivering powerful low-frequency audio that reproduces music in high fidelity. A wide frequency response of 25 to 200 Hz coupled with an adjustable 40 to 180 Hz crossover frequency helps the BIC deliver solid bass sounds. You can also adjust the speaker's crossover easily when needed. A 150-watt internal amplifier tops off the package and supplies the subwoofer with enough current to generate 116 decibels of sound -- more than enough to awaken the neighbors.
If you crave even more sonic thunder, take a look at the Hsu Research's VTF-15H subwoofer. Priced at $879 as of February 2012, this speaker packs a solid sonic punch while weighing in at over 100 pounds. A rosenut case encloses a 15-inch driver that belts out 350 watts of continuous power. Access the subwoofer's power, volume and phase controls easily from the back panel. You probably won't need such a powerful subwoofer for small or medium-sized rooms. However, if you need to fill a larger area with well-balanced audio that covers a wide frequency range, you'll have no problems doing that with this subwoofer handling your bass.
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