A speaker is an electro acoustic transducer that converts an electrical signal into sound. The speaker moves in accordance with the variations of an electrical signal and causes sound waves to propagate through a medium such as water or air.
After the acoustics of the listening space, speakers and other electro acoustic transducers are the most variable elements in a modern audio system and are usually responsible for most distortion and audible differences when comparing sound systems. The term “loudspeaker” may refer to individual transducers known as “drivers” and to complete speaker systems consisting of an enclosure including one or more drivers. Adequately reproducing a wide range of frequencies, most loudspeaker systems employ more than one driver, particularly for higher sound pressure level or maximum accuracy. The drivers are named subwoofers for very low frequencies; woofers for low frequencies; mid-range speakers for middle frequencies; tweeters for high frequencies; and sometimes super tweeters optimized for the highest audible frequencies. The terms for different speaker drivers differ depending on its application.
A full-range driver is designed to have the widest frequency response possible as these drivers are small, typically 3 to 8 inches (7.6 to 20 cm) in diameter to permit reasonable high frequency response, and carefully designed to give low-distortion output at low frequencies, though with reduced maximum output level. Full-range or more accurately wide-range drivers are most commonly heard in public address systems like television. In hi-fi speaker systems, the use of wide-range drive units avoids undesirable interactions between multiple drivers caused by non-coincident driver location or crossover network issues device.
A subwoofer is a woofer driver used only for the lowest part of the audio spectrum below 200 Hz for consumer systems. A woofer is a driver that reproduces low frequencies and the driver combines with the enclosure design to produce suitable low frequencies. A mid-range speaker is a loudspeaker driver that reproduces middle frequencies and the mid-range driver diaphragms can be made of paper or composite materials, and can be direct radiation drivers rather like smaller woofers.
A tweeter is a high-frequency driver that reproduces the highest frequencies in a speaker system and many varieties of tweeter design exist, each with differing abilities with regard to frequency response, output fidelity, power handling, maximum output level, etc.
The basic technology behind speakers is quite simple; a speaker is just a device that converts electrical energy into mechanical energy. More specifically, a speaker is made up of a several combination including a voice coil, a speaker cone, and the cabinet that holds all the parts inside. Sound reproduction begins when your receiver or amplifier sends audio signals to your speakers and when the electrical signal reaches the voice coil inside of the speaker, it creates a magnetic field. This electromagnetic energy causes the speaker’s cone to vibrate and move the air in front of it to which our ears perceive as sound.