Dynamic speakers are constructed using the same principles as the dynamic
microphone. These are the common speakers you see almost everywhere. They range
in size from the size of microphones (for example, earbuds) to several feet in
diameter. Usually, they range in size from about 3 inches in diameter to 12
inches in diameter. The diaphragm is usually made of stiff, heavy paper. The
voice coil may be several inches in diameter with very powerful permanent
magnets. Electromagnets may be used, but this is very rare.
A dynamic speaker. This is the same diagram as that used for the dynamic
microphone. The dynamic microphone and dynamic speaker work on the same
principle in reverse.
Here is a more detailed diagram
Horn speaker
A Horn speaker
A horn
speaker uses a relatively small dynamic speaker element that is directed through
a horn-shaped conduit. The horn structure itself does not amplify but improves
the coupling between the speaker and the air. Horns can help control dispersion[1]
at higher frequencies, which is useful in some applications such as sound
reinforcement[2]. The type of horn speaker known as a megaphone or bullhorn
consists of a series of nested horns.
Cut-away view of a bullhorn or megaphone speaker.
Piezoelectric speakers
The piezoelectric
speaker works on the same principle as the piezoelectric microphone.
Piezoelectric speakers are typically used for the high audio frequency ranges
(tweeters) or ultrasonic applications.
