Audio Video Production

1. Audio Basics Mr. Patricia Audio VideoProduction 1

2. Sound • Sound has two basic characteristics: • Loudness - measured in decibels • Frequency - measured in Hertz 2

3. Loudness • dBSPL (sound pressure loudness) • Measure of acoustic power • Sounds we can hear with our ears • 135 dB is considered “threshold of pain” • Ears ring • Point at which hearing damage can occur 3

4. Loudness • dBm • Unit of electrical power • Measured with VU meters • Digital VU meter • Analog VU meter • In live production, “0” is considered the maximum desirable sound level • 0 is also called “Unity” • In post-production, the audio levels are between -12 and -6 dB. • “0” should NOT to be reached 4

5. Frequency • Basic pitch of sound (how high/low it is) • Audible (hearing) range: 20Hz - 20,000Hz • 20Hz - extremely low pitch, rumble • 20,000Hz - extremely high pitch, higher than highest note of a violin • Common hearing range: 50Hz - 15,000Hz 5

6. Acoustics • Most sound booths incorporate different types of soundproofing materials • Hard walls; tile floors will allow too much reverberation • Reverb - sound remaining after the original sound stops • Too much soundproofing causes a dead, lifeless sound • Ideal room for recording and listening has free-standing, sound-absorbing items (furniture, rugs) 6

7. Types of mics • Dynamic microphone • Uses a small coil that moves within a magnetic field when activated by sound • Pros: • Rugged and durable • Can withstand weather and rough handling • Great for ENG (electronic news gathering) • Low Cost • No power necessary • Cons: • Larger and heavier • Not the best choice for quality audio 7

8. Types of mics • Condenser microphone • Has a plate that moves against another plate to produce a signal • Pros: • More sensitive • Better quality • Can be small • Cons: • Fragile and sensitive to shock and temperatures • Needs power • Battery • Phantom power supplied by camera or audio mixer • Expensive 8

9. Types of mics • Ribbon microphone • Uses a small ribbon (rather than coil) moving in a magnetic field • Similar to condenser mics in pickup quality and sensitivity • Produce warm, rich sound • Very sensitive to rough handling and moving air • Rarely used outside an audio booth 9

10. How microphones “hear” • Microphone Pickup Patterns • Omnidirectional • Picks up sound in all directions • Unidirectional (cardioid) • Focused hearing in one direction • Cardioid - “heart-shaped” pickup pattern • Hypercardioid - narrow pickup pattern with a “long reach” (for distances) Omnidirectional Cardiod Unidirectional 10

11. How mics are used • Handheld mic • Lavalier (lapel) mic • Boom (shotgun) mic • Desktop mic • Headset mic 11

12. Handheld Microphone • Held by the talent • Allows for talent to control mic’s location • Reporter can easily move it closer to interview • Singer can control intimacy of the sound by holding it closer • Field reporters - need dynamic handheld (rugged, durable) • Singers - need condenser handheld (better sound quality) • Disadvantages • Can be distracting (takes up visual space) • Talent’s hands are not free • Quality of sound depends on proper placement by talent

13. Lavalier Microphone • Small, rugged, omnidirectional • Usually clipped to shirts six to eight inches below talent’s chin • Advantages • Talent can move freely • Mic never moves • Sound is consistent • Disadvantages • Each on-camera subject requires mic • Requires proper setup and placement • Clothing may rub mic or muffle sound 13

14. Lavalier Microphone • “Dressing” lapel mics (hiding wires) • Under clothing • Have talent run microphone under the shirt • Clip mic to tie, lapel, collar or button flap • Careful of material rubbing mic or obstructing sound • Outside clothing • Run mic up the back of talent (outside clothing) and over the talent’s shoulder near the collar (under collar if possible) • Clip mic to lapel, collar, or button flap • Use gaffers tape (on talent’s back) to keep the mic cable from moving 14

15. Boom Microphone • Unidirectional mics intended to pick up sound without being seen on camera • “Shotgun” microphone mounted to the end of a telescoping boom pole • Pole has shock-mount to absorb all movement • Can be held above talent or at low angle below 15

16. Desktop Microphone • Microphone mounted on a small stand • Used for fixed positions • Often seen in: • Game shows • Speeches • Board rooms • Churches 16

17. Headset Microphone • Gives talent the freedom of movement while keeping the mic close to the mouth • Sometimes includes an earphone for talkback • Important for loud arenas and stadiums • Used by sportscasters, musicians/performers and public speakers • Small, wireless headsets with no earphone are sometimes called “countryman” mics 17

18. Wireless Microphones • Involves a microphone with a transmitter and a wireless receiver • Can come in any style • Lav, headset, hand • Allows complete freedom of movement without wires • Transmits through frequency bands • UHF • Least interference • More expensive • VHF • Cheaper • Most interference 18

19. Windscreens • Designed to let normal sound frequencies through and filter out wind noise • Made of acoustic foam rubber • Windsock • Used for shotgun mics • Ragged cloth that is pulled over the windscreen 19