Music Gizmo

A loudspeaker, speaker, or speaker system is an electromechanical transducer that converts an electrical signal. The term loudspeaker can refer to an individual device or driver, and a complete system consisting of an enclosure corporating one or more drivers and additional electronics.

Loudspeakers are the most variable elements in any audio system, and are responsible for marked audible differences between otherwise identical sound systems. Loudspeaker performance or accuracy in reproducing a signal without adding distortion is significantly poorer than that of other audio equipments.

Some important men who made history
Ernst W. Siemens was the first to describe the dynamic or moving coil transducer, with a circular coil of wire in a magnetic field and supported so that it could move axially. He filed his U. S. patent application for a Magneto electric Apparatus for obtaining the mechanical movement of an electrical coil by electrical currents transmitted through it was granted patent No.149797 on April 14, 1874.

Oliver Lodge filed for British patent No.9712 on Apr. 27, 1898, for an improved loudspeaker with nonmagnetic spacers to keep the air gap between the inner and outer poles of a moving coil transducer. This was the same year he applied for a patent on his famous radio tuner.

Thomas Edison was issued a British patent during 1881, for a system using compressed air as an amplifying mechanism for his early cylinder phonographs, but he ultimately settled for the familiar metal horn driven by a membrane attached to the stylus.

Harold Arnold around 1925 began program at Bell Labs to improve phonographic sound recording. The first priority was the electronic amplifier using the new vacuum tube, second was the microphone, and third was the loudspeaker that would improve the balanced armature units developed for public address.

Bell Laboratories in 1931 developed the two way loudspeakers, called divided range for the demonstration by H. A. Frederick of vertically cut records. The high frequencies were replaced by a small horn with a frequency response of 3000 to 13,000 hz, and the low frequencies by a 12 inch dynamic cone direct radiator unit with a frequency response within 5db from 50 to 10,000 hz.

How the loudspeakers used to work
The first loudspeakers used electromagnets because large, powerful permanent magnets were not available at reasonable cost.

The coil of an electromagnet, called a field coil, was energized by current through a second pair of connections to the driver. This winding usually served a dual role, acting also as a choke coil filtering the power supply of the amplifier to which the loudspeaker was connected.

AC ripple in the current was attenuated by the action of passing through the choke coil. However, AC line frequencies tended to modulate the audio signal being sent to the voice coil and added to the audible hum of a powered up sound reproduction device.

The quality of loudspeaker systems until the 1950s was, by modern standards, poor. Continuous developments in enclosure design and materials have led to the significant audible improvements. The most notable improvements in modern speakers are improvements in cone materials, the introduction of higher temperature adhesives, improved permanent magnet materials, improved measurement techniques, computer aided design and finite element analysis.

About the Author: Victor Epand is an expert consultant for music gear, speakers, and microphones. You can find the best marketplace for music gear, speakers, and microphones at these 3 sites: music gear, music equipment, speakers, loud speakers, and laser microphones, parabolic microphone.
Source: http://www.articlesbase.com

One of the oldest forms of loudspeakers are the horn loudspeakers that not only provide pure, high efficient, natural music but also fast and accurate transient response.

Basically what happens in the horn loudspeakers is that the diaphragm that is run by an electromagnet is supported by a horn, which improves the coupling efficiency between the speaker driver and the air. However, the horn is like an acoustic transformer that usually gives impedance matching between the diaphragm material and the air, having a low density. This will show the difference in density and motion of the air and of the driving element.

The first horn speaker that was invented looked very simple. It was a horn attached to a receiver and the sound quality was just awful. But it was better than that of the triode tube that was the base concept behind the horn speakers. Actually, this triode tube amplified the electric signal to the possible level and it could also produce audible output while driving the receiver. But the output power was really low. And later this conception gave birth to high efficiency loudspeakers, which produced high sound pressure level. It was in 1927 when Wente and Thuras, two Bell Laboratory engineers invented the compression horn driver, or rather say a driver.

Talking about the qualities of horn loudspeakers, the first thing that attracts is the harmonic, distortion less sound. It also offers a dramatic increase in dynamic capability in comparison to other such speakers, which suffered from dynamic compression. Horn loudspeakers have the capability to run efficiently with low powered amplifiers like single ended triode amps. Moreover, they can be designed to reproduce a wide range of frequencies using a single and small driver.

But the problem with horn speakers was that they were quite big and heavy. And soon after World War II more powerful and portable systems came into the market. But it will be wrong to say that they were completely out of demand because, although the horn loudspeakers lost the major demand but they survived in movie theatres.

These speakers are used for audio application due to the fact that horn reduces the need for exotic speakers. They are even used by audiophiles for sound reproduction. But there is a fact that not all type of horn speakers are used for this purpose. As there are ample designs that differ in length, material, drivers and many such things, so it is very confusing to state that which form is the best.

Horn loudspeakers are also used for public address and concerts. As it is mentioned earlier they provide high sound pressure level that is basically necessary for sound reinforcement and thus used for public address applications. They are used in concerts due to the high volume bass reproduction so that the bass can be heard as well felt by the concertgoers. And for this reason sometimes multiple loudspeakers in a group are used. But it should be noted that they give the same benefit as a single horn loudspeaker with a big mouth area. But off course, it should include greater power of multiple drivers.

About the Author: Victor Epand is an expert consultant for music gear, speakers, and microphones. You can find the best marketplace for music gear, speakers, and microphones at these 3 sites: music gear, music equipment, speakers, horn loudspeakers, horn speakers, and laser microphones, parabolic microphone.
Source: http://www.articlesbase.com

Whether it is home theater or movie theater, high fidelity speakers are the ones always in demand and in use too. These are the speakers that produce high quality, crystal clear sound with no distortion at all. Not only this, the frequency response too is unexpectedly accurate.

The system of High fidelity speakers generally includes digital audio signal sources like CD players; digital audio broadcasting, digital audiotape and HD radio tuners and amplifier. Infact, they also include components such as television, projector, DVD player and multi channel loud speakers. These together are often known as home theaters that are quite common in every home now a day.

These high fidelity speakers are not the new ones. The story began in 1920 with the introduction of electronic amplification and other sound reproducing systems like microphones. All the acoustically recorded disc records were getting replaced by the electrically recorded records, which proved to have better frequency response as compared to the disc records.

Meanwhile with the rise of radio, increased the popularity of loudspeakers and amplifiers. And thus radio receivers started using loudspeakers and electronic amplifiers to produce sound but phonographs remain mechanical and acoustic. But later, electronic phonographs were introduced which were played through listener’s radio.

Specifically speaking, there was an audio revolution going on which resulted in the development and popularity of the sound producing equipments. However, came 1930s and with it sound films developed. The movie industry felt that better fidelity, i.e., optical sound, better amplifiers and exclusive speakers can bring exciting effect to the sound track. The motion picture companies began developing amplification and loudspeakers to fill the theaters with high quality sound system.

This experimentation gave birth to woofers and tweeters, the different sections of loudspeakers for low and high frequencies. This development finally resulted into better fidelity sound equipment that can be used in homes too as homes equipment. But the cost of the whole equipment was high and not possible to own for people with average income.

After World War II ample technological experimentations and innovations took place that developed the condition of the audio system, especially the home audio system. Before there were only AM radio, but then came FM radio with wide audio bandwidth and better signal upgradation. Lower speakers were amplified and distortion free amplifier with wide dynamic range were used in the theater systems, sound reinforcement and then developed radio sets. Not only this, these speakers were attentive to higher frequency response and had higher power output capability.

The development story of the high fidelity speakers also includes innovations for musical artists. The reel-to-reel audio tape recording helped the artists make and distribute recordings with better fidelity.

Next period that is from 1950 to 1960 was the golden period for high fidelity speakers as they became popular with the audio manufacturers who used them as a marketing term to sell the equipments, which provide good quality sound reproduction. The system was later improved with the development of the Westrex single groove stereophonic record. Since then gradually the system of high fidelity speakers never looked back and are even now considered to be a highly accurate sound reproduction system.

About the Author: Victor Epand is an expert consultant for music gear, speakers, and microphones. You can find the best marketplace for music gear, speakers, and microphones at these 3 sites: music equipments, amplifiers, high fidelity speakers, woofers, and microphone.
Source: http://www.articlesbase.com