Sound Reinforcement (V1 Appendix D) Flashcards
Electricity
Flow of electrons through a circuit
Voltage and Volts
Measure of electric potential, Volt is the unit. It measures the pressure required to send one ampere of current through a resistance of one Ohm.
Current and Amperes
Measurement of how many electrons pass through a reference point each second. Ampere is unit of measurement
Resistance, Ohms, and Impedance
Resistance determines the limit for current, Ohm is measurement for resistance. Impedance is measurement of resistance along with other factors
Ground
Electrical reference for voltage measurements. Earth ground is electrical potential of the earth as a reference, signal ground is signal potential of a specific piece of equipment.
Decibel
Unit for intensity of sound. 0 dB is the lower limit of human hearing, 130 dB is the threshold of pain.
Standard Operating Levels
Mic Level is no signal- -20dBu. Line Level (mixing console, processing equipment, and electronic keyboards is -20 - +30, speaker is above +30 (power amplifiers)
Gain
Increase in amplitude of a signal
Attenuation
Reduction in amplitude of a signal
EMI
Electromagnetic Interference, sources can include TV, Radio, Cell phones, weather, power lines, lighting, power tools, medical equipment, mass transit systems, and other sound equipment. Also known as RFI (radio frequency interference)
DI Boxes
Direct Injection Box, convert unbalanced high impedance signals to balance low impedance microphone level signal
Ethernet Cable
Cable used to send information at high speeds between electronic devices, such as computers, routers, and IP (internet protocol) networks, and is referred to as a cat 5 or cat 6 cable.
Multi-Channel Audio Snake
A single cable with houses several discrete dual conductor shielded audio cables. Can consist of several elements housed in one element, or breakouts going into a junction box.
XLR Connectors
Three-pin XLR connectors are most commonly used when connecting microphones to mixing board, as well as various outputs to powered speakers. Used with dual conductor cables that help create balanced signals.
Tip-Ring-Sleeve/Tip-Sleeve
TS uses a single conductor shielded cable, used for unbalanced connections, and have one insulator ring to separate sleeve and tip.
TRS look similar but have an extra conductor on the shaft just above the ground. TRS use dual-shielded cables and create balanced connections, and can run L/R mono signals for stereo output.
Neutral Speakon/Powercon connectors
Neutral Speakon: Bridges connection between amplifiers and loudspeakers. Handle higher current than TS, TRS, or XLR and feature a safety locking mechanism.
Neutrik Powercon: Used as AC power connectors. Three-pole connector for neutral, line, and premating safety grounds. Also have locking mechanism.
IEC connectors
Common power supply couplers with a number of different applications and configurations. Meet IEC (International Electrotechnical Commission) standards and are classified from C1-C24. Most common is C13 (female) and C14 (male) for audio and computer equipment. These are rated up to 250V AC.
RJ45 Connectors
Registered Jack are a standard connector for network and telecommunication connections. They have 8 pin configuration and are similar to RJ11 (telephone jack).
Neutrik Ethercon Connectors
Essentially an RJ45 connector specially designed for audio, video, and lighting applications.
Dynamic Microphone
Most commonly used for live sound, largely because they are more economical and rugged. They have a voice coil/magnet assembly that works in conjunction with a small plastic diaphragm which vibrates in response to sound waves. The vibration within magnetic field is translated to electrical signal.
Condenser Microphone
Can be more costly and more sensitive to temperature and humidity. Live sound is possible but not as common. But, they deliver much clearer and natural sound, especially within higher-frequencies.
They have an electronically charged diaphragm/back plate that forms a sound-sensitive capacitor. Sound waves vibrate a thin metal diaphragm, which is mounted in front of a fixed metal back plate. Electrical charge is created between the two, and signal is generated based on the spacing between the two.
