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1 Sound 1 -- Microphones

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Sound 1 -- Microphones 1 Sound 1 Microphones Sound 1 -- Microphones 2 Classification: Microphones are classified by: Sound 1 -- Microphones 3 Classification: Microphones are classified by: – Operating Principle Sound 1 -- Microphones 4 Classification: Microphones are classified by: – Operating Principle -- What physical principle is used to convert mechanical energy into electrical energy? Sound 1 -- Microphones 5 Classification: Microphones are classified by: – Operating Principle -- What physical principle is used to convert mechanical energy into electrical energy? – Directional Characteristic Sound 1 -- Microphones 6 Classification: Microphones are classified by: – Operating Principle -- What physical principle is used to convert mechanical energy into electrical energy? – Directional Characteristic -- How does the microphone respond to sound arriving from different directions? Sound 1 -- Microphones 7 Classification: Operating Principle -- What physical principle is used to convert mechanical energy into electrical energy? Sound 1 -- Microphones 8 Classification: Operating Principle -- What physical principle is used to convert mechanical energy into electrical energy? – Carbon Sound 1 -- Microphones 9 Classification: Operating Principle -- What physical principle is used to convert mechanical energy into electrical energy? – Carbon – Piezo Sound 1 -- Microphones 10 Classification: Operating Principle -- What physical principle is used to convert mechanical energy into electrical energy? – Carbon – Piezo (piezo-electric) Sound 1 -- Microphones 11 Classification: Operating Principle -- What physical principle is used to convert mechanical energy into electrical energy? – Carbon – Piezo – Dynamic Sound 1 -- Microphones 12 Classification: Operating Principle -- What physical principle is used to convert mechanical energy into electrical energy? – Carbon – Piezo – Dynamic (moving coil) Sound 1 -- Microphones 13 Classification: Operating Principle -- What physical principle is used to convert mechanical energy into electrical energy? – Carbon – Piezo – Dynamic – Ribbon Sound 1 -- Microphones 14 Classification: Operating Principle -- What physical principle is used to convert mechanical energy into electrical energy? – Carbon – Piezo – Dynamic – Ribbon – Condenser Sound 1 -- Microphones 15 Classification: Operating Principle -- What physical principle is used to convert mechanical energy into electrical energy? – Carbon – Piezo – Dynamic – Ribbon – Condenser (capacitor) Sound 1 -- Microphones 16 Carbon Microphone: Sound 1 -- Microphones 17 Carbon Microphone: The movement of the diaphragm compresses carbon granules, varying the electrical current. Sound 1 -- Microphones 18 Carbon Microphone: Advantages: Sound 1 -- Microphones 19 Carbon Microphone: Advantages: • Cheap to manufacture Sound 1 -- Microphones 20 Carbon Microphone: Advantages: • Cheap to manufacture • Rugged Sound 1 -- Microphones 21 Carbon Microphone: Advantages: • Cheap to manufacture • Rugged Disadvantages: Sound 1 -- Microphones 22 Carbon Microphone: Advantages: • Cheap to manufacture • Rugged Disadvantages: • Requires external power source Sound 1 -- Microphones 23 Carbon Microphone: Advantages: • Cheap to manufacture • Rugged Disadvantages: • Requires external power source • Limited frequency range Sound 1 -- Microphones 24 Carbon Microphone: Advantages: • Cheap to manufacture • Rugged Disadvantages: • Requires external power source • Limited frequency range • Limited sensitivity Sound 1 -- Microphones 25 Carbon Microphone: Sound 1 -- Microphones 26 Piezo-electric Microphone: Sound 1 -- Microphones 27 Piezo-electric Microphone: The movement of the diaphragm bends a crystalline materiel, varying the electrical current generated. (Same principle as a BBQ starter wand.) Sound 1 -- Microphones 28 Piezo-electric Microphone: Advantages: Sound 1 -- Microphones 29 Piezo-electric Microphone: Advantages: • Cheap to manufacture Sound 1 -- Microphones 30 Piezo-electric Microphone: Advantages: • Cheap to manufacture Disadvantages: Sound 1 -- Microphones 31 Piezo-electric Microphone: Advantages: • Cheap to manufacture Disadvantages: • Fragile Sound 1 -- Microphones 32 Piezo-electric Microphone: Advantages: • Cheap to manufacture Disadvantages: • Fragile • High electrical impedance limits cable length Sound 1 -- Microphones 33 Piezo-electric Microphone: Sound 1 -- Microphones 34 Dynamic Microphone: Sound 1 -- Microphones 35 Dynamic Microphone: The movement of the diaphragm causes a small coil of wire to move in a magnetic field, varying the electrical current generated. (Same principle as bicycle dynamo.) Sound 1 -- Microphones 36 Dynamic Microphone: Advantages: Sound 1 -- Microphones 37 Dynamic Microphone: Advantages: • Good quality for reasonable price Sound 1 -- Microphones 38 Dynamic Microphone: Advantages: • Good quality for reasonable price Disadvantages: Sound 1 -- Microphones 39 Dynamic Microphone: Advantages: • Good quality for reasonable price Disadvantages: • Susceptible to external magnetic fields (hum) Sound 1 -- Microphones 40 Dynamic Microphone: Advantages: • Good quality for reasonable price Disadvantages: • Susceptible to external magnetic fields (hum) • Magnet is heavy Sound 1 -- Microphones 41 Dynamic Microphone: Advantages: • Good quality for reasonable price Disadvantages: • Susceptible to external magnetic fields (hum) • Magnet is heavy • Magnetic shielding is heavy Sound 1 -- Microphones 42 Dynamic Microphone: Advantages: • Good quality for reasonable price Disadvantages: • Susceptible to external magnetic fields (hum) • Magnet is heavy • Magnetic shielding is heavy • Inertia of coil limits sensitivity Sound 1 -- Microphones 43 Dynamic Microphone: Sound 1 -- Microphones 44 Ribbon Microphone: Sound 1 -- Microphones 45 Ribbon Microphone: The movement of the ribbon within a magnetic field varies the electrical current generated. Sound 1 -- Microphones 46 Ribbon Microphone: Advantages: Sound 1 -- Microphones 47 Ribbon Microphone: Advantages: • Good high frequency response Sound 1 -- Microphones 48 Ribbon Microphone: Advantages: • Good high frequency response Disadvantages: Sound 1 -- Microphones 49 Ribbon Microphone: Advantages: • Good high frequency response Disadvantages: • Fragile to mechanical shock, wind, voice pops Sound 1 -- Microphones 50 Ribbon Microphone: Advantages: • Good high frequency response Disadvantages: • Fragile to mechanical shock, wind, voice pops • Very low electrical impedance requires transformer Sound 1 -- Microphones 51 Ribbon Microphone: Sound 1 -- Microphones 52 Condenser Microphone: Sound 1 -- Microphones 53 Condenser Microphone: The movement of the charged diaphragm causes a change in electrical capacitance, varying the electrical current generated. Sound 1 -- Microphones 54 Condenser Microphone: Advantages: Sound 1 -- Microphones 55 Condenser Microphone: Advantages: • Thin diaphragm is light Sound 1 -- Microphones 56 Condenser Microphone: Advantages: • Thin diaphragm is light – good sensitivity Sound 1 -- Microphones 57 Condenser Microphone: Advantages: • Thin diaphragm is light – good sensitivity – good high frequency response Sound 1 -- Microphones 58 Condenser Microphone: Advantages: • Thin diaphragm is light – good sensitivity – good high frequency response • Can be made small Sound 1 -- Microphones 59 Condenser Microphone: Advantages: • Thin diaphragm is light – good sensitivity – good high frequency response • Can be made small Disadvantages: Sound 1 -- Microphones 60 Condenser Microphone: Advantages: • Thin diaphragm is light – good sensitivity – good high frequency response • Can be made small Disadvantages: • Requires external voltage source Sound 1 -- Microphones 61 Condenser Microphone: Advantages: • Thin diaphragm is light – good sensitivity – good high frequency response • Can be made small Disadvantages: • Requires external voltage source • Expensive to manufacture Sound 1 -- Microphones 62 Condenser Microphone: Sound 1 -- Microphones 63 Directional Characteristics: Sound 1 -- Microphones 64 Directional Characteristics: Omnidirectional Sound 1 -- Microphones 65 Directional Characteristics: Omnidirectional • Not directional Sound 1 -- Microphones 66 Directional Characteristics: Omnidirectional • Not directional • Diaphragm only exposed on one side (front) Sound 1 -- Microphones 67 Directional Characteristics: Omnidirectional • Not directional • Diaphragm only exposed on one side (front) • Sensitive only to pressure variation Sound 1 -- Microphones 68 Directional Characteristics: Omnidirectional • Not directional • Diaphragm only exposed on one side (front) • Sensitive only to absolute pressure variation • “Pressure microphone” Sound 1 -- Microphones 69 Directional Characteristics: Bidirectional: Sound 1 -- Microphones 70 Directional Characteristics: Bidirectional: • Directional Sound 1 -- Microphones 71 Directional Characteristics: Bidirectional: • Directional • Diaphragm exposed on both sides (front and back) Sound 1 -- Microphones 72 Directional Characteristics: Bidirectional: • Directional • Diaphragm exposed on both sides (front and back) • Sensitive to difference in pressure between front and back Sound 1 -- Microphones 73 Directional Characteristics: Bidirectional: • Directional • Diaphragm exposed on both sides (front and back) • Sensitive to difference in pressure between front and back • “Pressure gradient microphone” Sound 1 -- Microphones 74 Directional Characteristics: Bidirectional: • Directional Sound 1 -- Microphones 75 Directional Characteristics: Bidirectional: • Directional – Responds to sound from front and back Sound 1 -- Microphones 76 Directional Characteristics: Bidirectional: • Directional – Responds to sound from front and back – Rejects sound from sides Sound 1 -- Microphones 77 Directional Characteristics: Sound 1 -- Microphones 78 Directional Characteristics: Sound 1 -- Microphones 79 Directional Characteristics: Sound 1 -- Microphones 80 Directional Characteristics: Sound 1 -- Microphones 81 Directional Characteristics: Sound 1 -- Microphones 82 Directional Characteristics: Sound 1 -- Microphones 83 Directional Characteristics: Sound 1 -- Microphones 84 Directional Characteristics: Sound 1 -- Microphones 85 Directional Characteristics: Sound 1 -- Microphones 86 Directional Characteristics: Sound 1 -- Microphones 87 Directional Characteristics: Sound 1 -- Microphones 88 Directional Characteristics: Sound 1 -- Microphones 89 Directional Characteristics: Distance Factor: Sound 1 -- Microphones 90 Directional Characteristics: Distance Factor: • Microphones with higher distance factor can work farther from source. Sound 1 -- Microphones 91 Directional Characteristics: 3:1 Rule: Sound 1 -- Microphones 92 Directional Characteristics: 3:1 Rule: • Microphones should never be placed closer together than three times the distance between mic and source. Sound 1 -- Microphones 93 Directional Characteristics: 3:1 Rule: • Microphones should never be placed closer together than three times the distance between mic and source, to prevent comb-filtering. Sound 1 -- Microphones 94 Proximity Effect: Sound 1 -- Microphones 95 Proximity Effect: All directional microphones Sound 1 -- Microphones 96 Proximity Effect: All directional microphones exhibit a boost in bass (low frequencies) when working close. Sound 1 -- Microphones 97 Proximity Effect: All directional microphones exhibit a boost in bass (low frequencies) when working close. 2 feet Sound 1 -- Microphones 98 Proximity Effect: All directional microphones exhibit a boost in bass (low frequencies) when working close. 2 inches Sound 1 -- Microphones 99 Proximity Effect: All directional microphones exhibit a boost in bass (low frequencies) when working close. ¼ inch Sound 1 -- Microphones 100 Boundary Effect: Sound 1 -- Microphones 101 Boundary Effect: 1. Sound waves reflected from the floor or other surface cause phase cancellation at some frequency. Sound 1 -- Microphones 102 Boundary Effect: 1. Sound waves reflected from the floor or other surface cause phase cancellation at some frequency. 2. The closer to a surface the microphone is mounted, the higher the frequency at which the phase cancellation takes place. Sound 1 -- Microphones 103 Boundary Effect: 1. Sound waves reflected from the floor or other surface cause phase cancellation at some frequency. 2. The closer to a surface the microphone is mounted, the higher the frequency at which the phase cancellation takes place. 3. With the microphone mounted close to or directly on a large surface, any phase cancellation occurs at frequencies beyond the limit of hearing. Sound 1 -- Microphones 104 Boundary Effect: Advantages of placing a microphone close to a large boundary: Sound 1 -- Microphones 105 Boundary Effect: Advantages of placing a microphone close to a large boundary: • comb-filtering is inaudible Sound 1 -- Microphones 106 Boundary Effect: Advantages of placing a microphone close to a large boundary: • comb-filtering is inaudible • doubling of SPL since direct and reflected sound waves add. (+6 dB) Sound 1 -- Microphones 107 Boundary Effect: Advantages of placing a microphone close to a large boundary: • comb-filtering is inaudible • doubling of SPL since direct and reflected sound waves add. (+6 dB) • reverberation caused by surface eliminated at mic (direct to reverberant ratio improved by 3dB) Sound 1 -- Microphones 108 Boundary Effect: Advantages of placing a microphone close to a large boundary: • comb-filtering is inaudible • doubling of SPL since direct and reflected sound waves add. (+6 dB) • reverberation caused by surface eliminated at mic (direct to reverberant ratio improved by 3dB – mic sounds closer) Sound 1 -- Microphones 109 Boundary Effect: Advantages of placing a microphone close to a large boundary: • comb-filtering is inaudible • doubling of SPL since direct and reflected sound waves add. (+6 dB) • reverberation caused by surface eliminated at mic (direct to reverberant ratio improved by 3dB – mic sounds closer) • overall improvement of 9dB Sound 1 -- Microphones 110 Boundary Effect: Sound 1 -- Microphones 111 Microphone Inventory: Sound 1 -- Microphones 112 Microphone Inventory: Sound 1 -- Microphones 113 Microphone Inventory: Sound 1 -- Microphones 114 Microphone Inventory: Sound 1 -- Microphones 115 Microphone Inventory: Sound 1 -- Microphones 116