Home Glossary of Terms

Glossary of Terms

Signal / Technological Terms

  • FM – Frequency Modualted, typically refering to FM or HiFi audio (also called AFM) but also FM modualated video like VHS (colour-under) or LaserDisc (composite)
  • Baseband – This is a raw signal waveform like audio going to a speaker or composite video going to a CRT.
  • Bit Rate – The number of bits used to represent one second of audio. Calculated by multiplying the bit depth by the sample rate.
  • Bit Depth – The number of bits used to represent each sample of audio (CD’s are 16 bit, that old scratchy audio from your Commodore 64 computer was 8 bit, archival quality (now generally referred to as high definition audio) is typically 24 bit, with modern audio recorders using 32 bit float.
  • Sample Rate – The number of samples taken per second. e.g 44.1kHz 16-bit is what a CD uses, 48khz 24-bit being the standard for video camaras, alongside older consumer standard of 32khz 12-bit from Digital8/MiniDV tapes is not rare. Today 48/96/192kHz is common in what is now referred to as high definition audio but video normally has a track, but
  • Audio Channel – A single, mono stream of audio, two channels make up the term stereo, 6 channels make up the term 5.1 surround
  • Balanced Audio – a particular way of wiring audio to reduce noise in the signal. This requires an extra wire (e.g. 3 wires in total for a single mono signal) which is run out of phase to create a balanced output. Two common connection types are XLR and 3-Poll 1/4inch TRS support.
  • Noise Floor – The underlying lowest level of noise from a (usually) analogue audio track that you can not traditionally remove (though these days with digital you can)
  • Tape Hiss – The high frequency noise present on analog magnetic tape recordings. Caused by the size of the magnetic particles. Basically the same as the noise floor.
  • SNR – Signal to Noise ratio – this is the ratio of clean or clear information to noise or static unwanted information.

Hardware Terms

  • XLR – The name of a professional audio connector used in live sound and high end amps. Usually includes a balanced signal reducing noise through the audio chain
  • RCA – Typical audio phono connector found in typical home audio gear. Unbalanced only.
  • 6.35mm or 1/4″ Jack – The bigger connection often found on broadcast/radio/studio style headphones
  • 3.5mm or 1/8″ jack – The smaller connection often found on consumer headphones and field portable equipment (Phones, MP3 players, Camcorders etc)

Common/Consumer Terms

  • High Definition Audio – A consumer term for higher than CD quality. CD quality is 16 bit, 44.1kHz, HD Audio formats typically start at 24 bit, 96kHz.
  • IPS (In Plane Switching) – A type of monitor display
  • LCD (Liquid Crystal Display) – Common Digital Display
  • CRT (Cathode Ray Tube) – Universal analouge display (PC/Video/Ossiliscopes etc with diffrent phosphers for diffrent TV systems and applications)
  • OLED
  • QLED

MISC Terms

  • 3-head cassette deck – A name for a cassette deck that has a dedicated play head which is perceived to be of higher quality
  • Demagnetiser – A tool to take the undesired magnetism from a tape head, caused by flowing magenetic tapes across it
  • Capstan – The name of the system that clamps the tape and pulls it through to play it
  • Open Format – Best for archiving as the format has no restrictions (such as licencing) for its use and will be readable for generations to come. E.g. FLAC.

Digital Media Terms

  • Dolby Digital – A standard for multi-channel audio
  • Container Format – A wrapper file can includes audio, video, subtitles, chapters, images
  • Encoding Format –
  • Compression – For purposes of Audio and video, a lossy way of making the file smaller without losing ‘perceptable’ quality
  • FLAC – Free Lossless Audio Codec – Confusingly this can be both a codec and a container, but typically think of it as a codec
  • Uncompressed Audio – Audio that hasn’t lost any detail from it’s original and is of it’s original size
  • DAW – Digital Audio Workstation – I.e. Adobe Audition, Davinci Resolve (OCENAudio/Audacity also)
  • DAC – Digital Analog Converter, converts digital to audio and vice versa, can be a chip in a CD player, or a device on your deskVideo Codec – The computational method used to compress video into a file such as h264, h265 / HEVC
  • MPEG-2 – Used by DVD to Broadcast with varing bitrates and depths making the major diffrances in quality, considered legacy but well supported.
  • H264 MPEG4 – The most compressible high quality codec available today for older devices, typically at least twice the file size of H265, often considered as higher quality than H265
  • H265 HEVC – The most compressible high quality codec available today with broad hardware support, typically 50-70% more efficient than H264
  • H266 – The next generation codec after H265 which again reduces the file size by another 50-70 % for the same perceivable quality, almost no hardware support available today