SOUND BASICS

Drop the “techno babble” what do I need to know?

Wavelength: The distance between any point on a wave and the equivalent point on the next phase. Literally, the length of the wave.

Amplitude: The strength or power of a wave signal. The "height" of a wave when viewed as a graph.

Frequency: The number of times the wavelength occurs in one second. Measured in kilohertz (Khz), or cycles per second. The faster the sound source vibrates, the higher the frequency.

Sound Wave Properties

Microphone Basics

Microphone = Transducer

Device which converts one form of energy to another.

Types:• Dynamic• Condense

r• Ribbon • CrystalMic Level & Line Level• Mic level – small current• Line level – 0.5 -2V• Same level used by CD players

VCR/DVD players, etc.

Types of MicrophonesDynami

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The dynamic microphone uses a wire coil and magnet to create the audio signal

Diaphragm vibrates in response to incoming sound waves, the coil moves backwards and forwards past the magnet, creating a current in the coil which is channeled from the microphone along wires

Condenser A capacitor has two plates with a voltage between them. In the condenser mic, one of these plates is made of very light material and acts as the diaphragm. The diaphragm vibrates when struck by sound waves, changing the distance between the two plates and therefore changing the capacitance.

Phantom Power – Charge of between 12 and 48 volts components take as much as it needs.

Directional Patterns

OmnidirectionalPicks up sound evenly from all directions (omni means "all" or "every").

Uses: Capturing ambient noise; Situations where sound is coming from many directions; Situations where the mic position must remain fixed while the sound source is moving.

UnidirectionalPicks up sound predominantly from one direction. This includes cardioid and hypercardioid microphones.

Cardioid (heart-shaped)Sound is picked up mostly from the front, but to a lesser extent the sides as well.

Hyper cardioid (Shot gun mics)Very directional and eliminates most sound from the sides and rear