You may not know this, a full frequency speaker

Why even two "sound knowledge advanced" talking about the speaker unit? Simple, because you hear the sound is from the bottom of the unit. No matter the is how powerful the speaker (or no speakers), and how perfect minute sound, if less good unit, everything is in vain. So the unit is very important, it should admit of no doubt.
　　Then, a middle unit, ambiguous, what is it? But there are a lot of people say the most important is the Alto sound band, which I applaud. If you have like me so boring, try to sing a song with a separate a treble unit listen Tsai, or listen to Paganini's Violin Concerto with a separate bass unit, will be deeply recognize the mediant unit cute. I think you will agree, if forced you can listen to music with a unit, you will choose a look something like the mediant unit. Because without him, because you know (or suspect) speakers will be issued in range of the frequency bands, and we the people of earth's hearing is mainly in the range, music constitute the main body is in here.
　　The design of the mediant unit
　　Gyrus said "refers to the concept of Jiang" treble, can continue to extend to the Alto range. Because the sound to any unit can be deconstructed to voice diaphragm, diaphragm suspension and drive system. But because of the different frequency of work, these elements are gradually evolved to a specific range in the evolution of so many years. However, its shape and material etc. there are many changes, especially the diaphragm material in recent years, it is full of tricks.