（1）Speakers have two terminals (two leads). When using a single speaker two pins regardless of positive and negative polarity, the speaker also use two pins have polarity.

　　（2）The speaker has a paper bowl, its color is usually black, and white.

　　（3）The speaker's appearance has a round and oval shaped two categories.

　　（4）On the back of the speaker is a magnet, and the magnetic speaker will feel the presence of a magnetic field with a metal screwdriver.

　　（5）The speaker is mounted on a machine panel or in a sound box.