| what does the Greek ‘micro’ and ‘phon’ stand for |
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| who coined the name microphone |
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| what does a transducer do |
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| convert acoustic energy into electrical energy |
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| another name for carbon mics |
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| contain a section filled with carbon granules and the vibration of the diaphragm |
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| the vibration of the diaphragm of a carbon mic causes teh granules to be compressed over time |
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| what were carbon mics used for |
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| military applications and telephone handsets |
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| what does piezin stand for |
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| who discovered the Piezoelectric effect |
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| how do Ceramic/Crystal miss operate |
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| quartz, tourmaline, Rochelle salt, cane sugar, barium titanate |
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| can you apply Phantom Power to a crystal mic |
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| what mics use Piezoelectric materials |
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| what principle operates Magnetic/dynamic/ribbon mics |
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| FaraDays Law of Magnetic Induction |
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| what does the ‘e’ of e=Blv stand for? |
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| electromotive force in volts |
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| what does the ‘B’ of e=Blv stand for? |
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| what does the ‘l’ of e=Blv stand for? |
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| what does the ‘v’ of e=Blv stand for? |
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| velocity of the conductor moving through the magnetic field |
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| what is the combination of ribbon and magnets considered |
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| what will doubling ribbon length do |
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| yield a 6dB increase in output, but causes a loss of high frequency |
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| can you use Phantom Power with a Ribbon mic |
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| how thick is a ribbon in a ribbon mic |
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| another name for condenser mics |
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| who developed condencer mics |
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| who first mass produced condencer mics |
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| before placing a mic on a stand ensure: |
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the boom is extended over a leg
body screwed into boom tightly |
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| how to store mics with magnetic structures |
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| in their protective felt bags |
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carbon
ceramic/crystal
magnetic/dynamic
ribbon
condeser |
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| the size of carbon granules in carbon mics |
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| approximately 100 microns |
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| how to fix packing problem in carbon mics |
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| gently rap against a hard surface |
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| what does piezein stand for |
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| when was the Piezoelectric effect discovered |
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| what is the piezoelectric effect |
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| an electrical voltage is created when the piezoelectric material is subjected to mechanical stress |
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| how does a crystal mic operate |
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| sound waves hitting the diaphragm put pressure on the piezoelectric material causing a voltage |
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| type of transducer found in acoustic guitar pickups |
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| Another name Magnetic-Dynamic Microphones |
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| electrodynamic or electromagnetic mics |
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| how do magnetic-dynamic mics operate |
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| the principles of magnetic induction |
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| who discovered magnetic induction |
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| Faraday’s Law of Magnetic induction states…. |
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| moving a conductor (coil of wire) through a magnetic field will cause a voltage to be induced across the conductor |
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| amount of voltage induced in magnetic induction is proportional to… |
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magnetic field strength
length of the conductor
velocity of conductor moving through the magnetic field |
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| shape of modern dynamic mics |
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| what are dynamic mic diaphragms usually made of |
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| plastic or coated with aluminum |
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| coil of wire wrapped around the dome |
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| sensitivity of dynamic mics |
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| less responsive to transient frequencies due to the size of the diaphragm |
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| outside measurement range |
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| size of the ribbon in ribbon mics |
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| sensitivity of the ribbon mic determined by: |
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ribbon thickness
corrugations per inch
tensioning |
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| where is the ribbon of a ribbon mic suspended |
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| between the poles of a strong magnet |
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| output of a ribbon mic dependent on: |
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conductor length
movement of the conductor in the magnetic field
magnetic field strength |
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| only practical means of increasing output voltage of a ribbon mic |
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| increasing magnetic field strength |
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| transient response of a ribbon mic |
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| 8.5lbs (due to size of magnet) |
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| a nano-enabled material or acoustic nano-film that makes the ribbon extremely strong |
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| Soundwave Research Laboratories |
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| how does a condenser mic operate |
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two parallel metal plates, each holding an opposing charge, creates a capacitor
sound hits the diaphragm changing the distance causing change in capacitance
sent to a circuit taht translates this change into an electrical signal that is analoguous to the sound wave |
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| what are the two metal plates of a condenser mic |
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| the diaphragm and the backplate |
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| what is the diaphragm in a condenser mic made of |
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| thin piece of metal or plastic, such as Mylar, coated with gold or nickel |
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| thickness of the diaphragm in a condenser mic |
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| how is the backplate of a condenser mic constructed |
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| usually made of milled brass with a number of holes drilled into it |
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| what are the holes in the diaphragm of a condenser mic for |
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| provide damping, acting as a spring of sorts |
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| what does a condenser mic require |
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| what can the preamp of a condenser mic be |
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| how does an electret condenser mic make capacitance |
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| permanent static electric charge |
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| what is power from battery or phantom used for in an electret condenser mic |
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| power the mics internal pre-amp |
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| what is used to power a condenser mic |
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external power supply unit (PSU)
phantom power
battery |
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| what are the 3 voltages for phantom power |
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| what does the basket of a condenser mic do |
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protect the capsule from physical damage
protect from stray RFI |
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| a plot that describes the sensitivity of a mic to sounds arriving from any direction over a 360 degree range |
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| sounds that arrive at the 0 degree position relative to the mic capsule |
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| sound that arrive from angels other than the 0 degree position relative to the mic capsule |
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| equal sensitivity to sounds from all directions |
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| sensitive to sounds arriving from the front and rear |
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pressure microphone: omni
pressure gradient: bidirectional |
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| Altec/Western Electric 639 |
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| has both a ribbon and a diaphragm |
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figure 8 (bi)
Super-Cardioid
Hyper-Cardioid
Cardioid
Sub-Cardioid
Omnidirectional |
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| how polar patterns are created electrically in condensers |
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a pair of cardioid capsules are mounted back-to-back
(outputs are combined to create other polar patterns) |
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| creating omni pattern electrically |
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| equal amount + from each cardioid capsule |
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| creating bidirectional pattern electrically |
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| equal amount + from one and – from the other |
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| creating cardioid electrically |
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| creating super/hyper cardioid patterns electrically |
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| more + from one and less – from the other |
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| creating sub cardioid electrically |
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| more + from one and less + from the other |
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| as the distance from the source decreases, microphones with directional polar patterns will exhibit an increase in low frequency response |
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| amount of dB increase in Shure 57 at 100 Hz when placed 1/4″ from the sound source |
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has extended low frequency pickup
less proximity effect than directional mics |
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pattern usually very even except at highest freqs
more proximity effect than cardioid or hyper-cardioid |
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| most sensitive to sounds arriving from the front while rejecting sounds from the rear |
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| sensitive in a slightly narrower pattern in the front than a cardioid and has a small lobe at the rear |
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| sensitive in a narrower pattern in the front than a cardioid and has a prominent lobe at rear |
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| extremely narrow area of sensitivity in front with extended “reach” also has multiple lobes which vary in position with frequency |
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| how is the shotgun pattern created |
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| using an interference tube |
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| coverage angle of cardioid |
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| coverage angle of supercardioid |
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| coverage angle of hypercardioid |
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| coverage angle of bidirectional |
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| angle of max rejection in cardioid |
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| angle of max rejection in supercardioid |
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| angle of max rejection in hypercardioid |
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| angle of max rejection in bidirectional |
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| rear sensitivity (relative to front) of onmi |
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| rear sensitivity (relative to front) of supercardioid |
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| rear sensitivity (relative to front) of hypercardioid |
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| rear sensitivity (relative to front) of bidirectional |
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| ambient sound sensitivity of omni |
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| ambient sound sensitivity of cardioid |
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| ambient sound sensitivity of supercardioid |
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| ambient sound sensitivity of hypercardioid |
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| ambient sound sensitivity of bidirectional |
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| distance factor of cardioid |
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| distance factor of supercardioid |
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| distance factor of hypercardioid |
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| distance factor of bidirectional |
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| distance factor of sub-cardioid |
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| max level possible with a certain amount of measured distortion |
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| total dynamic range of the mics internal pre-amp |
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| measured in millivolts per Pascal |
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| pressure and pressure variations are expressed in Pascals (Pa) or N/m2 |
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| comparing sound pressure levels in decibels to pascals |
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Real Time Analyzers
FFT analyzers |
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used to maintain safe working conditions
used to prevent violation of sound level and noise pollution laws |
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| what is generated commonly by calibration devices |
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| what is less commonly generated by calibration devices |
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| allow sound to reach the rear of the capsule/diaphragm, to create cardioid, super cardioid, and hyper cardioid patterns |
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| measurement similar to how our hearing works |
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| measurement close to overall sound level |
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| small diaphragm electret condensers, extremely flat frequency response omnidirectional pattern |
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| used to calibrate sound pressure measurement devices |
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