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Introduction: A simple speaker is made up of a short list of components with very specific functions. This makes it easier to explain how exactly it works. The components are: the basket, voice coil, stationary magnet, diaphragm, suspension, spider, and the wires. These parts are displayed and labeled in Figure 1.These components are a speaker’s most basic parts but they are also the most essential. If one of these parts malfunctions, the sound quality of the speaker will be severely affected. In this report, I will explain how all of these parts are put together to create sound.  What is Sound? To fully understand how a speaker works, sound must first be defined and explained. Sound is created when things come into contact with each other, and this even includes air particles. Air particles are the medium in which sound waves are usually received by people. When something moves quickly, it crashes into the air particles at a rapid rate and those particles crash into other adjacent ones, creating a sound wave. This vibration is composed of two states: when the air molecules are more compressed and when they are less compressed than the normal conditions (Robin, 2001). When this wave of air travels to a person’s eardrums, the vibration is interpreted by the brain and so we hear the sound (Harris, 2001).  The Basket: Everything needs a support system or a frame of some sort. In the case of a speaker, the basket fulfills that part. The basket is a casing that is usually metal which surrounds the whole speaker and its primary function is to keep all of the components attached together. The basket however also protects the speaker and is also there for looks. A basket would usually be made out of metal but any sturdy material could be used as a substitute. The design of the basket also varies. A simple design would suffice at creating clear crisp sound but a more elaborate design would not hurt. In figure three, you see that the speaker has a basket made out of half a coke can.  The Voice Coil: On one end of the wire from a speaker that is connected to the audio player while the other end is connected to the voice coil. The voice coil is the simplest form of an electromagnet. This is where an electric current is sent through a coil of wires to make the coil itself a magnet. The polarity of the coil depends on the charge of the electric current running through it and changes by the audio player (Harris, 2001). Along with the stationary magnet which would later be mentioned, this magnetic property of a coil plays a very key part in the science of a speaker. The coil itself is just made out of ductile wires and is glued onto a light weight hollow tube called the voice coil former (V.C. former). The size of the V.C. former is dependent on the size of the pole piece, found in the stationary magnet. It is slightly bigger that the pole piece. The V.C. former is made up of a ridged light weight material for two reasons: to have an absolute shape that would fit perfectly with the pole piece and so that it could with stand the heat from the voice coil.  The Stationary Magnet: There is a huge round magnet on the bottom of every speaker that is called the stationary magnet. The stationary magnet has two parts: the magnet and the pole piece (Harris, 2001), which are permanently attached to each other. The whole stationary magnet is connected to nothing but the basket which turns out to be very important. If it was attached the voice coil, the component of the speaker closest to the stationary magnet, the movement of the voice coil and the diaphragm would be restricted and the speaker would not work nearly as well as it could. The circular ring like shape of the magnet is also crucial to its job. The empty space in the middle of the magnet is where the voice coil is placed though. The voice coil has to be centered in the very middle of the magnet to function properly. When centered, the area between the end of the coil to the start of the magnet is called the magnetic gap. Unlike the voice coil, the stationary magnet’s polarity is permanently positive. The change in the polarity of the voice coil causes the stationary magnet to attract and reject the coil; pulled down when it is negative (negative cycle) and push up when it is positive (positive cycle) (Armstrong, 2004). The back and forth movement is carried out at a rapid rate.   The Diaphragm: When you look at a speaker, the diaphragm will probably be the first thing you will notice. The Diaphragm is what actually creates all of the sound because it is the part that causes the vibration in the air. The material that a diaphragm is made of is more important that anything else in the speaker. Due to its strenuous work, the diaphragm has to be made of a light, hard, durable and flexible material. In the case of the diaphragm, flexibility is just as important as durability. If it was not durable, as the diaphragm move back and forth at such a rapid pace, the air would rupture it after a short period of time. If it was not flexible, the sound quality would be sacrificed. There are a few different materials that are usually used to make diaphragms. Cheaper speakers use a type of paper while more expensive ones use plastic and metal. There are also top the line speakers that even use wood and Japanese washi paper to make the diaphragm to recreated instrumental sound at a new level.  The Suspension: A diaphragm moves back and forth but it could only do this freely because two of two things: the suspension and the spider. The suspension connects the diaphragm to the basket and it allows all of the movements done by the diaphragm. Like the diaphragm, the suspension has to be very durable, but as durable as it is, it has to be even more flexible. Unlike the diaphragm, the suspension should be soft, not hard (Armstrong, 2004). This allows it to cushion the diaphragm and it also prevents it from creating sound waves of its own.  The Spider: What the diaphragm does for the diaphragm on top, the spider does it on the bottom (Harris, 2001). The diaphragm needs a position where it is in rest and this is where the spider collaborated with the diaphragm. Spider suspends the diaphragm in the air to keep the rest of the speaker that might affect the sound away from it. As seen in figure 10, the spider is folded several times so it could be flexible enough to adapt to the movements of the diaphragm.  The Wires: The wiring of a speaker is important as the rest of it. If the wires are disconnected, no sound would be produced. The most important wires on a speaker are the wires used on the voice coil and the two short wires that are connected to the diaphragm. The wires used for the voice coil must be extremely thin but at the same time ductile. Due to its size, the voice coil wire could be wrapped around the V.C. former multiple times and with multiple layers so that when an electric current passes through, the magnetic property of the voice coil is enhanced. The two short wires connected to the diaphragm are also connected to the voice coil wire. These two wires are braided, meaning they are made up of multiple wires. This also means that they are very durable. When the diaphragm vibrates, the wires have to do the same. If they were not braided, they would rip after a few songs.
Citations: Harris, Tom. (2001) How Speakers Work. Retrieved February 27, 2006 from www.howstuffworks.com Armstrong, Anthony. (2004), Speakers: What They Do. Retrieved February 27, 2006 from http://stereos.about.com/cs/componentguide/a/loudspeakers.htm Robin, (2001) Sound Frequency. Retrieved February 27, 2006 from http://www.execulink.com/~robin1/da_freq.html |