Sound and Microphones

Resonance

waves bouncing off of walls over and over to reinforce themselves (sustain pitch)

Harmonic

full numbers of Hertz (1, 2, 3)

Enharmonic

not full numbers of Hertz (1.5, 2.5, 3.5)

Formant

fixed resonant peak in a sound that stays put regardless of pitch (vowel sounds - the way you shape your mouth or instrument producing a different sound)

Amplitude

• objective version of loudness

• we can hear between 0-120 db

• how high or low the top of the wave gets from zero

• measured in decibels

loudness

• subjective version of loudness

• depends on person and frequency

dB SPL

decibels of sound pressure level (objective measurement above the threshold of hearing)

Fletcher Munson Equal Loudness Curve

• our ears are more sensitive to frequencies 1 khz to 5khz (harder to hear super low and high)

Envelope

• change in sound over time

• ex. violin sneaks in then dies out

• ex. snare drum immediate quick sound and immediate release

• attack, release, decay, sustain

phase

the relationship of sound waves from two or more sources (how sound waves work together → when they work together you get overtones

• in phase - waves peaks and troughs align

• out of phase - waves peaks and troughs do not align

Intonation

• more hz and harder to tune when higher (faster waves)

• slower waves less hard to tune lower notes

why do we use cents

• lower notes are slower and higher notes are faster and

doppler effect

• moving toward you fast enough so sound waves are getting smooshed together and the pitch gets higher

• moving away makes waves stretch, lowering the pitch

Pitch

• Cents = pitch

• hertz = frequency

frequency

• quality of sound dependent on rate of vibrations that produce it

• to create octave you double hertz

fundamental

prominent note (is not the overtones) - the pitch you hear

tranducer

converts one kind of energy into another (mics are transducers)

Diaphragm

a thin membrane that catches the sound waves vibrating and amplifies the sound

omnidirectional

pics up sounds everywhere

cardioid/ unidirectional

sound everywhere but back

super cardioid

picks ups top and small park of bottom

hyper cardioid

more from top and more from bottom

figure 8 mic

picks up all top and all bottom

frequency response

what you put in is what you get out

proximity effect

if the sound source is closer to you and the amount of room sound (the more directional (figure 8) the more proximity effect

off axis coloration

talking into the side of the mic changes frequency response and off axis picks up less high frequencies

gain staging

• if there are several places to turn up and down have them set at about all the same

XLR cables

• mic cable

• has three conductors - ground, signal, signal phase flipped

• signal goes out of prongs and into sockets

what three and used to actually record

ribbon, condensor, dynamic

carbon

• needs power

• high sensitivity

• high distortion

• poor frequency response

• used for home phones

ceramic/crystal

• creates power

• low sensitivity

• high distortion

• poor frequency response

• walkie talkies

dynamic

• makes own power

• high sensitivity

• low distortion

• great frequency response

• durable and inexpensive

• slow transient response (less pingy)

Ribbon Mic

• makes own current

• high sensitivity

• low distortion

• great frequency response

• great transient response

• very very expensive

• used in studios

Condenser Mics

• require +48V phantom power

• high sensitivity

• low distortion

• great frequency response

• great transient response