Each speaker can reproduce a given frequency range. In some common usage typically use a speaker called the full-range speakers, because it has a relatively large frequency range, for example, can play 80-15000 Hz. Full-range Speakers are commonly used in portable radios, transistor radios, radio tubes, old console radio or television.
There are also speakers that can reproduce only a limited frequency range and are optimized for this then. Woofer has a large membrane and reproducing low frequencies (bass) optimized for high performance. Tweeter is optimized for reproducing of high frequencies (treble), which works with small diaphragms which work better than the large ones. Then there are the midrange speaker, which are optimized for medium-frequency.
Some speakers are integrated in a hi fi box, which are optimized for specific frequency ranges and produce only this, for example, a low, midrange and tweeter. In most cases the crossover is used, consists of different filters, which only allow the speaker to receive the frequency with which they can process. Since high and in the midrange compared to the woofers are too loud, is made at the crossover for this level adjustment with resistors, as is seen in the example circuit shown below.
During the manufacture of hi-fi speakers will be more things to consider. The most important thing in this case, known as Thiele Small parameters. With this, for example, the correct case size specified of woofer. But this is a specialized field that is not discussed further here. There are a lot of literature!
