Thesis Abstract

Audio loudspeaker (output transducer) is on of the most essential and powerful device used in telecommunication system. This is device capable of converting electrical signal into sound and vice versa. It is made up of few time of non-magnetic wire wound on a light cylindrical former that is mounted so that it can move freely insides the magnetic field of a strong permanent magnet. The speaker cone it attached to the voice coil and attached with a flexible mounting to outer ting of the speaker support.The device was contracted and operated based on the principles of electromagnetic induction which was clearly stated by faradays and langue laws of electromagnetic induction. This speaker has power rating of low watts and 16ohms impedance.The materials used in made up of particle board of ¾ thickness tweeter and cross over network..This device constructed locally can compete favourably well with the imported one (with international standard) the information in this write up comprises of the construction operation a detailed information of each component parts and various used of output transducer (loudspeaker)

Thesis Overview

BACKGROUND INFORMATION OF STUDY Imagine the difficulty it would result in telecommunication system is not the invent of output transducer (loudspeaker) it cannot be over emphasized the vital role of loudspeaker in distant communication system A deceive capable of converting electrical signal to audio (sound) signal -As water is very vital to aquatic organisms so as transducer is very necessary in telecommunication system.The loudspeaker are almost always the limiting element on the fidelity of a reproduced sound in either home or theatre. The loudspeaker involve electromechanical process where the applied audio signal must move a cone or other mechanical device to produce sound like the original sound wave. The quality of sound produced by the loudspeaker is dependent on the quality of the loudspeaker (ie its Wattage impedance rating) the enclosure and the magnitude of signal input to the loudspeaker.Because there is a definite -home” or equilibrium position for the speaker cone and there is elasticity of the mounting structure there is inevitability a free cone resonant frequency like that of a mass on a spring. The frequency can be determined by adjusting mass and stiffness of the cone and voice coil and it can be damped & broadened by the nature of the construction. But that natural mechanical frequency of vibration is always there and enhances the frequency range near resonance.Enclosure: Enclosure employed in this construction comprises of ¾ particle board skilled with cloth materials to beautify its surface. A primary function of a speaker enclosure is to keep the sound coming from the back of a driver come from going into the room. The sound from the back of a driver is 180 degrees out of phase with the sound from the front destroying the low frequency performance.To limit all these deficiencies all loudspeaker enclosure must posses the following features since resonant frequency is a barrier to quality sound production1. It must be air tightHas walls that do not vibrate a lotDoes not have strong internal resonanceIsolates each driver (speaker) from the otherHas a gemmating compatible with good sound reproductionFor more efficiency and accurate sound reproduction this device is equipped with cross over network and tweeter.AIM AND OBJECTIVESThe aim of this work is to locally construct an audio speaker that will complete with the imported ones.