Audio System Basics Flashcards
analog signal definition
electrical current flowing through a device or cable, that directly represents sound vibrations in air.
Basic Analog Signal Flow: Stage Inputs
instrument, di box, (amp), stagebox, FOH mixer
Basic Analog Signal Flow: PA Outputs
mix outputs (returns), crossover, LF amp, HF amp, monitors/speakers
gain staging
- Maintaining optimal gain at each stage of the signal chain to minimize noise and distortion
- as much signal to noise ration as possible
distortion occurs when…
the signal exceeds the maximum level of any
amplifying stage.
SNR means…
Signal to Noise Ratio
Signal levels: 3 types
mice level, line level, speaker level
types of mics
dynamic, condenser, ribbon, Electret-condenser microphones
Phantom Power
Power supplied to microphones through a balanced microphone cable
which devices require phantom power
Needed by condenser mics, electret-condenser mics, and some other devices such as D.I. boxes.
which mics ignore phantom power?
dynamic mics
which mics get damaged by phantom power?
ribbon mics
which cable has 1 signal carrying conductor?
unbalanced cable
which cable has 2 signal carrying conductors/
balanced cable
how long can a balanced cable be?
up tp 100m
how long can an unbalanced cable be?
shorter than 10m
Common Mode Rejection
This is the ability of an amplifier to reject the effect of voltage applied to. both input terminals simultaneously.
high impedance means…
high likely hood of picking up noise
anything that changes the signal level is called a…
gain stage
distortion is..
anytime you change the audio (tone, equalization, normally negative change)
headroom
difference between our signal level and the maximum limitation of our sound system
dynamic range
difference between the and the softest possible useful signal
dBu is used to…
measure differences in signal level
what does the “u” on mixing consoles refer to?
unity; zero decibels, will cause no change in signal level
