Home theater subwoofers are generally classified by their brand, their size and enclosure, and whether they are powered from a dedicated source. The size and shape of the enclosure, also known as the speaker box, play a large part in the quality of bass sound the subwoofer emanates. Many different speaker manufacturers make home theater subwoofers. Well-known brands of home theater audio include Sony, Bose, and Polk Audio. Non-powered subwoofers are called passive subwoofers.
The box that holds the speaker and the speaker cone are the basis of the sound qualities produced by home theater subwoofers. Types of speaker enclosures include sealed boxes, ported boxes, and bandpass boxes. Differences in speaker enclosure construction can influence the quality and frequency range performance of speakers. Some speaker enclosures have vents, while others are airtight, while others still use a combination of sealed and open chambers to sway the tone of the bass sound. Shapes of subwoofer cone include round, square, and hexagon.
Size variations in subwoofers can greatly impact the difference in the quality of the sound results. Generally, the size of the subwoofer needed for a room depends on the size of the room. A large subwoofer is usually able to produce a higher level of bass sound than a small subwoofer, but a too-large subwoofer can cause issues, including distortion in home theater sound and disruption in neighborhood relations. Rooms that naturally amplify bass might need smaller home theater subwoofers than usual, while a small room with a great deal of dampening material like carpet, rugs, and furniture may need a slightly larger subwoofer.
An easy way to tell whether home theater subwoofers are powered or not is to check for a power plug included with each subwoofer. If the subwoofer needs a power supply to operate, it is a powered subwoofer. If it relies on power from another component and does not use its own power source, it is not powered. Powered home theater subwoofers are important because the dedicated power supply gives the subwoofer the electrical energy needed to greatly amplify low audio tones.
While the brand of home theater subwoofers does not necessarily matter as much as choosing the right equipment for the installation space, some brands of home theater audio can provide better quality and customer service than others. Getting a subwoofer from a quality company can help increase the chance that the product was constructed well using superior components. When a product fails, a company with a reputation to protect will be more likely to remedy the problem than an unknown discount speaker manufacturer.