Digital Audio Basics

STUDY
PLAY
DAC
Digital to Analogue Converter
ADC
Analogue to Digital Converter
Firewire
connector designed to carry digital signals and available with 4 pin and 6 pin connections
Sample Rate
Number of samples taken per second in Digital Audio
Bit Rate
Number of 'bits' used per sample in Digital Audio
44.1kHz - 16Bit
CD Audio Quality
Hz
Samples per second in Digital Audio
kHz
x 1000 (eg 44.1kHz = 44,1000Hz)
Audio Interface
Item of equipment that connects between mixing console and computer. Carries out ADC and DAC
96kHz - 24Bit
Professional Digital Audio Quality
20hz - 20kHz
Frequency range of CD Digital Audio at 44.1kHz/16Bit
Optical In/Out
Digital ins and outs that use an optical cable or 'light pipe'
Digital Clock
The sample rate used by the audio interface and all other digital recording equipment in the studio.
MIDI In
Receives MIDI data from a keyboard and transmits it to the sequencing software or other sound source
MIDI Out
Transmits MIDI data from the keyboard or computer to play sounds on an external sound source
MIDI Thru
Transmits MIDI data directly from the MIDI In socket, through the device.
Main Out (Analogue) - on audio interface
Connects the sound from the computer back to the mixing console and/or monitors. (After DAC)
Mic/Line Input - on audio interface
Analogue socket that takes signal from an instrument or microphone and sends it to the ADC in the audio interface
Dynamic Range
A range between the quietest and the loudest sound that can be heard, recorded or played without distortion
Frequency range
A range of frequencies that can be heard, recorded or played back
SNR
Signal to Noise Ratio - The range between the noise floor and the loudest sound that can be recorded or played back without distortion. Similar to Dynamic Range
SNR of 96dB SPL
The Signal to Noise Ratio (Dynamic Range) available in a 44.1kHz/16Bit digital audio system
MP3
An audio file format used for Internet and iPods that is created by compressing the data to make it a small file
Lossy
A compressed audio file. data has been lost or taken away to make it smaller
Lossless
A high quality and uncompressed audio file format
PCM
Pulse Code Modulation
Pulse Code Modulation (Definition)
PCM. Pulse-code modulation (PCM) is a method used to digitally represent sampled analog signals. It is the standard form of digital audio in computers, Compact Discs, digital telephony and other digital audio applications.