RTV 497 / THE 530 Sound and Audio

Sound in an environment Sound wave –Compression / rarefaction Frequency / Measured in hertz Amplitude / Measured in decibels (db-spl) –AM/FM, kHz / MHz (r.f.) Attack/sustain (internal dynamics)/decay -- sound envelope Acoustics / Psychoacoustics / binaural hearing Absorbed / Reflected Direct / Indirect (echo & reverberation)

Some issues with sound Equal loudness principle--depending on loudness we don’t hear low and high frequencies as well as we hear middle Masking--Hiding of some sounds by other sounds by other sounds when each is a different frequency and they are presented together. Loud over soft / lower-pitched over higher Acoustical phase--the time relationship between two or more sound waves at a given point in their cycles Timbre--a sound’s unique tone quality or tone color

Production Room Sound Design Ergonomics – human element in designing room Sound Absorption and Reflection Diffusion--scattering of sound waves Diffraction--spreading or bending Resonance--vibration of an object at the same frequency as the original body’s frequency Lively or Dead Room Isolation

Why Important? Equipment does not exactly re-create realistic, ‘natural’ sound You have to compensate Hidden close mic ADR / looping Recording voice track without ambient sound Record interviews w/o ambient sound

Sound Frequency Spectrum Bass –Low bass, 1st & 2nd octaves, Hz –Upper bass, 3rd& 4th octaves, Hz Midrange –5th, 6th & 7th octaves, ,048 Hz –Upper midrange: 8th octave, 2, ,096 Hz Treble –9th & 10th octaves, 4, ,384 Hz

Digital Recording Sampling: takes periodic samples (snapshots, voltages) of the analog signal and converts that information into digital data Sampling frequency: the rate at which the signal is sampled: 44.1 kHz, 48 kHz Think of film at 24 fps – each still frame is a ‘sample’ (snapshot) of information in 1/24 of a second

Digital Recording Quantization: how many ones and zeroes to represent each sample A quantity expressed as a binary number is called a digital word. 10 is a 2-bit word, 101 is a 3-bit, 1010 is a 4-bit etc. The greater the number of the quantizing level ( an 8 bit vs. 10, a 2 bit) the more accurate the representation of the analog signal.

Mics -- Review Sound Sound Frequency Spectrum –Bass, midrange, treble Frequency / Hertz Amplitude / decibels Acoustics Direct / indirect sound –Echo / reverberations

Microphone Directional Patterns Omnidirectional / nondirectional Unidirectional / Directional/ cardioid –Super, hyper, ultra Bidirectional (see reading for diagrams)

Cardioid range Cardioid Supercardioid Hypercardioid Compare to parabolic

Professional Mic types Moving coil/dynamic Ribbon Capacitor/condensor Transducer – changes energy from one form to another – in this case sound waves into an electrical current

More about mics and sound Common analog audio connectors –RCA (phono), ¼” (phone), mini-plug, XLR –Jack (‘female’) vs. plug (‘male’) Close vs. distant miking –Cross-pair, mid-side as some distant miking approaches Wide – range of frequencies Flat – accurately recreates frequencies Colored response – changes frequencies (lavaliere boosts high frequencies, for example

Common mic types lavaliere headset handheld studio/boom mounted, TV boom –Perambulator boom, giraffes, fishpole PZM (boundary mic)

Audio Mixing Equipment Three things you mix –Sources, techniques, aesthetics Audio console or DAW ProTools or Adobe Audition 5 console functions –Amplify, switch, route, mix, balance Various console inputs Routing: patch panel

Other console terms Program / Audition Monitor vs. cue Master pot VU meter / PPM (analog / LED) Muting system Foldback (IFB note) Pad / trim / gain / AGC Pan Pot Submixer & pre-amp

Other audio mixing terms Compressor Limiter Equalizer (EQ) Filters –High pass, low pass, band pass, notch Stereo vs. multi-track recording –Basics of multi-track / mixdown

Three things you mix... Music –Production library, royalty-free loops –BMI, ASCAP, SESAC –blanket license vs. ‘needle drop’ –SoundExchange fees SFX -- Production library, Foley Voice –Narration vs. dialogue –Walla difference

Audio layering Initially recording ‘clean’ / dry sound. No flubs in narration. No distracting sound bite content. Multitrack / mixdown You must view and set audio levels You must balance audio throughout All foreground at see outline link