Expensive receivers, DVD players, amplifiers, or HTPCs may produce high quality audio signals, but the speakers produce the actual sounds. In other words, all the expensive components in your home theater network would be worthless without quality speakers producing quality sounds.
The reverse is also true in that high quality speakers can produce distorted sounds if the audio signal is of low quality. Therefore, the overall system from source–components to cables to speakers must be taken into account to receive the desired high quality sounds produced by speakers.
The sounds speakers produce are very subjective and can only be judged by you, the listener. However, it can be very difficult to judge speakers with the many formats, sizes and types out there. To make things more difficult, speakers are highly dependent on their surrounding environment. Therefore, speakers may sound great when you are auditioning them at the store, but sound distorted when you bring them back home. If you can, make sure you can audition the speakers at home, and return them if they don’t perform as desired.
Inside A Speaker
Sounds are produced by vibrations in the air. The more vibrations per second (i.e. higher frequency), the more high pitch there is in a sound. The less vibrations per second (i.e. lower frequency), the more bass there is in a sound. An average person can hear sounds from 20 to 20,000 Hz; therefore, speakers have to produce sounds at a minimum from 20 to 20,000 Hz.
Drivers in speakers are how these frequencies are produced. However, it is difficult for one driver to produce lower frequency and higher frequency sounds at the same time. Therefore, speakers have multiple drivers with each driver producing a specific frequency range. The most common drivers are tweeters, midrange, woofers, and subwoofers.
Tweeters – produce the higher frequency spectrum sounds. High frequency sounds are in the range of 2000 Hz and up. Tweeters are very small and normally around 1 inch in diameter.
Midrange – as the name suggests, midrange drivers produce sounds in the midrange frequency. This is usually in the range of 200 – 500 Hz up to 2000 – 3000 Hz. Midrange speakers size range from 4 inches in diameter up to 8 inches in diameter.
Woofers – produce the lower frequency sounds, but don’t necessarily have to go to bottom of the spectrum as subwoofers do. Their frequency range is typically from 500 Hz down to 80 Hz or below. Woofers speakers size range from 8 to 12 inches in diameter.
Subwoofers – produce sounds in the lowest frequency range typically at 80 Hz and below. Ten inches and up are typical sizes for subwoofer speakers. Subwoofers are usually stand–alone speakers that get placed in a corner. The reason for their large size is the considerable amount of power required to produce low frequency sounds. Therefore, a large amplifier with its own power souce is needed to give enough power to the subwoofer.