Transcript Audio and Sound Control

Audio Lesson
The Dynamics of Sound for Video
Production
Recording Audio
Designed to add drama
Designed to accurately recreate or
express a desired listening experience.
The sound engineer must create
selective hearing, or try and select the
sounds, the audience will hear and
eliminate the sounds you don’t want to
hear.
The mind can block out unwanted
sounds
Terminology
Audio: The Latin word for sound
Pick up pattern: The area a microphone
can hear
Frequencies: The vibration rate that
creates sounds
Range: (or Dynamic Range) the
frequencies of sound the microphone
can hear
Terminology (Cont.)
Amplitude: The intensity of the sound.
The relative loudness of the audio
signal.
Foley Art: The technique of recreating
sounds.
Cardiod: The shape of a microphone
that resembles a heart shaped pick up
pattern
Terminology (Cont.)
DAT: Digital Audio Tape. This is a format that
records sound onto an audio tape that
records ones and zeros onto tape.
HiFi: High Fidelity recording. Often refers to
the recording of differing signals for left and
right audio channels.
Mono: The recording of a single audio track.
Terminology (Cont.)
Mic Level: The signal is a low voltage
signal. Less than .1 volts
Line level: The signal is a little higher
voltage. Around 1 Volt
Acoustics: The ability of a material to
reflect sound.
Impedance: the resistance of the
microphone.
Terminology (Cont.)
Unidirectional: pick up of sound from
one direction
Omnidirection: The pick up of sound
from all directions
The Characteristics of
Sound
Sound is invisible but can be
diagrammed by the ratio of voltage/time
Wave is called a Sine wave
0
Amplitude
TIME
= 1 cycle or hertz
Audio Signal Levels
Low Level – Microphone level. Very low
voltage (signal) levels
High Level – the voltage output level of some
microphones, audio mixers, VCR’s, etc.
PA Level – Very high Amplitude output levels
produced by Power Amplifier output.
(Dangerous levels of electricity)
Always disconnect the power to audio
equipment when wiring!!!!
Audio Sources
Microphones
Recorded sound devices
Phonograph
 CD/DVD
 MP3 players
 Tape
 VCR/Cassette
 Cart Machines

Types of Microphones
Dynamic
Ribbon
Condenser
Dynamic
Dynamic microphone is like a tiny
speaker
Tends to be rugged
Reliable and most used type
Good for hand-held microphone use
Used by singers in concert
Ribbon Microphone
Very sensitive to touch – fragile
Used in professional recording studios
Can be hand held but not usually used
as a live performing microphone
Extremely expensive
Extremely fragile
Extremely sensitive
Condenser Microphone
Requires a battery
Wide range of quality and cost
Used were size is a factor
Can be made to fit a very small
enclosures
Can be used for recording, hand-held,
lapel, and for portable recording
Classifications of
Microphone Pick up
Patterns
Omnidirectional
Unidirectional
 Cardiod
 Supercardiod
 Hypercardiod
Omnidirectional
The Microphone has a circular pick up
pattern.
Found on most lapel, stage, and
general pickup microphones.
Microphone
Pick up
area
Cardiod
Heart-shaped Pick up pattern
Most common type
Microphone
Super Cardiod
Used for more directional pick up needs
Hyper Cardiod
Extremely directional.
Often used on the side lines of a
sporting event to hear the action on the
field
Sound Control
An audio mixer combines audio sources
Combines and adjust for different sound
level inputs. I.e.: A microphone level is
lower than a CD input. The Gain for the
Microphone must be adjusted higher
than the CD level input.
Summary
Audio is just as important than video
Audio has many different levels or
voltages
There are many types of microphones
There are many types of pickup
patterns used in audio
Sound control is as important as mic
selection.