Microphone types and characteristics essayDocument Transcript
Unit 17 Audio Production Processes Assignment 3Microphone types and characteristicsHistory of the microphone;1876 - The year in which the first microphone was invented using an earlytelephone device, the inventor Emile Berliner had created by using the bellcompany telephones, he was looking for different way to improve thetelephone and created a new type of transmitter which allowed you to increasethe volume of speech when spoken into. “A loose contact transmitter”1878 – The later development of microphones after Emile Berliner’s invention, David Edward Hughescreated the first carbon microphone; along with many other inventors who tried to expand on theoriginal discovery of microphone technology.1931 - As radio broadcasts were becoming more popular and the carbon microphone did not fit theneeds as well as would be liked, the first ribbon microphone was introduced, the RCA PB-31designed by Harry F Olson.1964 – James West & Gerhard Sessler released the electric microphone, the most commonly usedand reliable microphone, used a lot in current times because of the device being more portable ,still with a high precision microphone.How a microphone works –Microphone – “an instrument capable of transforming sound waves into changes in electric currentsor voltage, used in recording or transmitting sound.” 1. When a microphone is spoken into the sound waves which are made by your voice travel towards the microphone using the vibrations in the air. 2. “Inside the microphone, the diaphragm (much smaller than you would find in a loudspeaker and usually made of very thin plastic moves back and forth when the sound waves hit it.” 3. The coil inside the microphone moves backwards and forwards due to the vibrations from the sound waves. 4. “The permanent magnet produces a magnetic field that cuts through the coil. As the coil moves back and forth through the magnetic field, an electric current flows through it.”
Unit 17 Audio Production Processes Assignment 3 5. The current which flows through the microphone due to the above actions, the original sound waves are turned into electricity, due to this happening it is possible to amplify the electric current and then play out of a loudspeaker.Types of microphones;Dynamic microphone – This style of microphone uses vibrations of the sound waves. The soundwaves travel through the microphone which has a metallic coil with a magnetic field around itcaused by a magnet, this allows the current to flow.Electret/condenser microphone - These two types of microphones are both similar in the way thata collected charge of electricity is created between two pieces of metal. “Condenser micsmake use ofa thin piece of metal foil that is stretched above another piece of metal, as the foil moves it changesthe capacitance of the system. This can be detected and turned into a current.” Whereas an Electretmicrophone keeps the back piece of metal with a constant flow of electricity flowing through it.Electret microphones are used in mobile phones because they can be mad extremely small and havea good response to frequencies.
Unit 17 Audio Production Processes Assignment 3Ribbon – The type of microphones are similar to dynamic microphones, using air particle movementcreated by the sound waves when they reach the aluminium ribbons which are surrounded by amagnetic diaphragm, a fixed ribbon unlike the dynamic which is allowed to vibrate, the downside ofthis is that the ribbon microphone produces a lower electrical signal so and output transformer isoften used to boost the power.Carbon - The first microphone design, still used to this day but not for recording music or soundswith high frequency’s. These types of microphones worked well when the were invented due tobeing durable and cheap, so all radio stations could afford them, the same design was used inphones. Sound waves when they hit the microphone reach carbon particles, which vibrate creating acurrent.
Unit 17 Audio Production Processes Assignment 3Crystal - “Sound vibrates the diaphragm that moves the armature that bends the crystal. Smallcopper foil strips attached to the Rochelle salt crystal transmit the electricity out to the amplifierconnector.”Lavalier - A microphone used by reporters, singers and many more circumstances, the type ofmicrophone used in it is either a dynamic or electret because the microphone can be reduced tosuch a small size making it easy to use.Rifle – This type of microphone is for recording something far away, undercover surveillance etc.,has to be a high frequency microphone so that it picks up conversation from a long distance, eitherplaced on the end of a camera or on a beam.Boom – A boom microphone is used for television programs, for recording conversation from a shortdistance , usually placed on a rod and put in the air out of shot on camera.Radio – This is a wireless microphone, used a lot in day to day life, by singers on stage, radiopresenters, most things broadcasted live on television or too a audience these are used, it works bya wireless channel transmitter fitted to both the microphone and the receiver, when set to the samechannel what is said into the input (the microphone) is transferred to the output (the receiver).Boundary microphone (PZM) – A boundary microphone is used in many situations, in a office whencommunicating between offices, on the stage of a theatre so that dialogue can be picked up and putforward to the crowd. A high frequency microphone is used inside the design so that sounds from adistance can be picked up, used for its amplification of acoustics.
Unit 17 Audio Production Processes Assignment 3Polar patterns;Omni – a commonly used microphone design, able to pick up sound from a 360 degree radius andnot alter the definition of the sound taken in.Bi-Directional – this polar pattern only picks up sound waves from the front and the back of themicrophone, all sounds coming in from the sides won’t be heard or will be distorted, cannot be usedwhen recording a lot of things has to be for a select cause e.g. Recording instruments.Cardioid – this polar pattern is used for live broadcasting or for singer’s performances on stagebecause the sound waves can only be picked up from the front, so the audience’s noise does notaffect the quality of the sound coming from the microphone.Hyper-Cardioid – much like the cardioid but due to having the small back sound pickup it produces abetter sound because it has the all-round frequency response.Shotgun – “A "shotgun" mic carries these techniques to extremes by mounting the diaphragm in themiddle of a pipe. The shotgun is extremely sensitive along the main axis, but possesses pronouncedextra lobes which vary drastically with frequency. In fact, the frequency response of this mic is sobad it is usually electronically restricted to the voice range, where it is used to record dialogue forfilm and video.”Purpose of Different Microphones;It is important that when planning to record a subject or recording a subject that you have thecorrect microphone which is suitable for the job, depending on the Omni directional patterns whichpick up sounds from different parts of the circumference of the microphone which is more suitablefor recording. In a studio the main types of microphones are Dynamic & Condenser.Dynamic – This type of microphone is used when recording particularly instruments and vocalsbecause the microphones can withstand high-pressure levels, useful when recording with loud guitaramps in the background. The problem with them is that the sound achieved is not as clear as from acondenser.Condenser – This is the most commonly found microphones, chosen for studio work due to it abilitytoo produce a louder sound than other microphones. A more delicate expensive microphone so hasto be taken care of, dynamics are used instead because of there rugged ness. When looking intobuying condenser’s you have either large diaphragm microphones which is for recording deeperpitch sounds with some sounds causing distortion because of theresensitivity and small diaphragm
Unit 17 Audio Production Processes Assignment 3microphones have the best response to sound converting the sounds quickly also the microphoneisn’t as sensitive to some sounds so the sound coming from the output isn’t distorted, very clear.
Unit 17 Audio Production Processes Assignment 3References –Microphone definition - http://dictionary.reference.com/browse/microphonePolar patterns - http://artsites.ucsc.edu/EMS/Music/tech_background/TE-20/teces_20.htmlHow a microphone works - http://www.explainthatstuff.com/microphones.html2 & 4, how a microphone works - http://www.explainthatstuff.com/microphones.htmlShot gun polar pattern - http://artsites.ucsc.edu/EMS/Music/tech_background/TE-20/teces_20.htmlDynamic & Condenser microphone picture -http://artsites.ucsc.edu/EMS/Music/tech_background/TE-20/teces_20.htmlCarbon Microphone diagram -http://upload.wikimedia.org/wikipedia/en/4/4e/Carbon_microphone.svgCondenser microphone definition - http://www.jt30.com/jt30page/howmicswork.htmlRibbon Microphone diagram -http://www.ustudy.in/sites/default/files/images/ribbon%20microphone.jpgCrystal microphone diagram & description - http://www.jt30.com/jt30page/howmicswork.html