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.