- Speaker profile, introduction, photo, classification, advantages, history and notes are presented.
- With another name loudspeaker, speaker refers to devices to convert electrical or audio signals into sound. Equipped with a power amplifier, speaker can transform the sound to a louder one.
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- The photo of a general speaker of sound system
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Speaker or loudspeaker is the terminal of an entire sound system. With function of converting audio energy into corresponding sound energy and radiate it to the space, speaker is an extremely important part of sound system. It responsible for the task of converting electrical signals into acoustic signals for listening by human ears.
Normal loudspeaker integrate power amplifier and speaker sound system to be be directly matched with general audio sources to form a complete audio combination. Users do not need to worry about the reasonable selection of power amplifiers and speakers. So the loudspeaker is getting popular in users.
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Being an electromechanical device, loudspeaker is a must equipment in concert hall, meeting hall, cinema, dancing halls, theaters, auditoriums and stadiums.
Except the separate style, speakers is often be used on electric equipment, such as Walkmans, CD players, DVD players, video recorders, etc.
It is needed when you want to listen to a music in home.
They are often found in schools, sporting events, festivals, and other crowded places.
Loudspeaker is also used in various applications right from hearing aids to air raid sirens.
- Using occasion
- Speaker can be divided into two categories: professional speakers and home speakers.
- Audio frequency
- full-band speakers, bass speakers and subwoofer speakers
- Purpose
- Generally can be divided into main speakers, monitor speakers and back-to-listening speakers, etc.
- - Main speaker is generally used as the main sound box of the system to undertake the main sound reproduction task.
- - Monitor speaker is used for monitoring in control rooms or recording studios. It offers low distortion, wide and flat frequency response, and little modification of the signal.
- - Back-to-listening speakers, also known as stage monitor speakers, are generally used on the stage or dance hall for actors or band members to monitor their singing or performance.
- Cabinet Structure
- it can be divided into sealed speakers, inverted speakers, labyrinth speakers, sonic tube speakers and multi-cavity resonant speakers.
- - Closed Enclosure is the simplest speaker system. It was proposed by Frederick in 1923 and consists of a speaker unit installed in a fully sealed cabinet. This kind of small airtight speaker is also called air-cushioned speaker.
- - Bass-Reflex Enclosure) is also called Acoustical Phase Inverter. In its load, there is a sound outlet opening on a panel of the cabinet. There are various opening positions and shapes. But most of them also have acoustic conduits in the holes.
- - Acoustic Resistance Enclosure is deformation of a phase-inverted speaker. It is filled with sound-absorbing material or structure in the sound outlet duct, which acts as a semi-closed box to control the phase-inversion effect and reduce the anti-resonance frequency to broaden the bass frequency band.
- - Labyrinth Enclosure is named after the transmission line of the classical electrical theory. There is a sound tube made of sound-absorbing wall panels on the back of the speaker, the length of which is 1/4 or 1/8 of the wavelength of the low-frequency sound to be boosted .
- - Drone Cone Enclosure is a branch of bass reflex speaker, also known as empty cone speaker
- -Coupled cavity speaker is a cabinet structure between the closed type and the bass reflex type. It was published by Henry Lang in the United States in 1953. Its is output through the sound hole driven by one side of the cone.
- - Horn type Enclosure. Its horn mouth is coupled with a larger air load at the mouth, and the driving end has a small diameter. The back of this type of speaker is fully sealed, and the pressure in the chamber is mostly on the back of the speaker cone.
- Material
- wood, plastic, metal.
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Loudspeaker is basically composed of three parts: speaker, crossover, and cabinet.
The speaker is the weakest but the most important device in audio equipment. It covers types of electric, electromagnetic, piezoelectric and digital, etc. Single cones, composite cones and composite horns are both available.
The cabinet is used to eliminate the acoustic short circuit of the speaker unit, suppress its acoustic resonance, broaden its frequency response range, and reduce distortion. The cabinet shape covers desk and floor type. -
Audio is a kind of electrical energy. The loudspeaker has ability to keep the essential acoustical character of this energy.
The motor ( voice coil ) of a speaker convert the electrical energy into mechanical energy.
According to the pattern of the original audio signal, the voice coil vibrates a diaphragm that in turn vibrates the air in immediate contact with it and produced a sound.
Most loudspeaker consists of several speakers, from low-frequency to high frequency, because a single speaker cannot complete reproduce the entire frequency range of original sound. The low-frequency speaker is called a woofer. The high-frequency speaker is called a tweeter. Sub-woofers, super-tweeters or midrange speaker is included in some high end loudspeakers. -
On February 14, 1876, Alexander Graham Bell created a "telephone" in history. This device allowed human voices to reach farther places than shouts. Since then, humans understood the conversion relationship between sound and electricity.
By separating the driving force from the diaphragm, S. G. Brown invented armature headset in order to better replay the recorded sound in 1910.
In 1910, Baldwin invented 'balanced armature' headset. It is a movable iron piece (armature) set up in the middle of a U-shaped magnet. When the current flows through the coil, the armature will be magnetized and repelled by the magnet to drive the diaphragm to move. Being a low-cost design, this technology is mostly used in telephone tubes and small headsets.
In the mid-1930s, electrostatic speakers were created based on the principle of condenser microphones.
In the early 1950s,the'constant charge theory' was applied it to the Quad electrostatic speaker design. -
Most speakers are very easy to be installed, used and maintained.
Blue-tooth speaker is easy to install without hassles of wiring.
Speakers are available in different sizes for different locations and applications.
Loudspeakers are used to produce high amplitude sound waves to cover larger audience in open air or huge conference room or theater.
It is easy to be separated out from an Audio System.
Nowdays, speaker is a standard configuration of computers and mobile-phone, one of the most important component.
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Speaker is easy to be interfered by nearby radio equipments.
Wireless speaker has range limitations, which make it only available in part of occasions.
Part of outdoor loudspeaker annoy people nearly.
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Keep your speaker dry, because paper cones, circuit components, coils can be harmed in a humid environment.
Vibration or collision can disconnect circuit or cause the speaker magnet to lose magnetism.
Inappropriate impedance matching of speaker leads to bad performance or even damage.
Over-power-working may the audio to be burned out.
Avoid using the speaker under high temperature conditions, which lead to aging of the paper cone.