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Different Types of Speaker

Different Types of Speakers
 
All loudspeakers operate by moving a mass of air in a way to create a sound that people can hear. There are 5 main ways this is achieved:
 
 
The dynamic enclosure
The Electrostatic speaker
The Horn-type
The Planar-Magnetic speaker
The Subwoofer
 
 
For most music listeners, the dynamic enclosure is the type of speaker that you will most likely purchase. It will have at least one woofer (low-frequency, or bass) driver, and one tweeter (high-frequency, or treble) driver arranged along the face of the speaker cabinet. Higher-performance speakers may have those drivers arrayed on the rear of the speaker enclosure as well.
 
The electrostatic speaker is a radical change from the dynamic speaker concept.
 
Where the dynamic speaker has a series of different drivers to provide sound, the electrostatic uses one driver, a thin membrane stretched between two conductive, stationary panels, and then charged with an electrical current. And where the dynamic speaker is typically a passive device, the electrostatic speaker must have an outside power source: it must be plugged into an electrical outlet. To produce sound the membrane receives an alternating current from the amplifier. This alteration of polarity (positive or negative charge) combined with the power of the current running through the diaphragm cause it to be moved between these conductive panels, causing sound waves to be created. The sound created by electrostatic speakers provides for crisp, detailed high-frequency reproduction. However, because the thin membrane moves so little, it cannot produce realistic low-frequency (bass) sound.
 
A speaker similar to the electrostatic is the Planar-Magnetic type of speaker. Planar-magnetic speakers replace the wide, tall, thin diaphragm of an electrostatic design with a thin, tall, narrow metal ribbon. The thin ribbon then suspended between a pair of powerful magnets instead of charged metal panels. Planar-magnetic speakers operate by passing a current through the metal ribbon. As the current passes along, the ribbon is attracted to or repelled from the magnets surrounding it. The resultant movement generates sound waves in the air surrounding the ribbon. This process is similar to the electrostatic design without the need for charged panels. In addition, the speaker need not be plugged in to the house electrical system.
 
The next type of speaker, the Horn type, is actually a modified version of typical dynamic speakers. They make use of traditional dynamic drivers placed at the small end of a cone-type structure, or wave-guide, to produce sound more efficiently than traditional drivers. The combination of the driver and the attached structure (wave-guide) is often referred to simply as a horn. Horn speakers are typically more efficient (in other words, have a higher sensitivity) and can fill even large areas with impressive sound volumes.
 
The final variety of speaker is the subwoofer. Usually, a "sub" are just one-driver dynamic loudspeakers. They have one large woofer (bass, or low-frequency driver) from 8" to as much as 20" in diameter. The enclosure most likely has a bass port to increase the sub's low-frequency performance. A sub has a difficult life, despite its relative simplicity. Its sole job is to provide low-frequency sound to the listener. Its performance is centered only on bass sounds close to the lower limit of human hearing. But it has to do this job of supplementing the bass-handling of the main speakers in your system while not muddying the sound or being overpowering and non-musical.

Brass & Granite Audio

www.Oregondv.com
Salem, OR 97303

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