Mastering or Production Mastering -- Transfer of sound material to a production master, while preserving the sound quality of the original and conforming to the technical considerations of the mass production format.
Pre-Mastering or Re-Mastering -- Transfer of sound material with a conscious effort to improve the sound quality of the original through the use of processing such as EQ, compression, etc. Generally performed in a sonically neutral environment. Also referred to as Mastering.
Master -- A Mono or Stereo recording. Can refer to the final mix-down from a recording session, a "pre-mastered" or processed recording, or a recording used in the mass production of copies.
Production Master -- A Master created specifically for the production process. For cassettes, there are two types of masters:
Analog Masters are a single four track analog tape containing the A-side stereo material in the forward direction, and B-side stereo material recorded in the reverse direction. The tape is spiced end to end in a bin-loop player, and all four tracks are recorded on to bulk cassette tape at high speed, which is then loaded into tape shells.
Digital Masters are recorded as a .WAV file, and stored on CD-ROM. They are played back at high speed by a Digital Bin player, and recorded on to bulk cassette tape, which is then loaded into tape shells
DAT -- Digital Audio Tape. Originally meant as a consumer format, it has been adopted as a standard in the Professional Audio community. It is susceptible to various problems, so care should be taken in its use to avoid problems.
Analog Bin -- In cassette production, a tape player in which an analog tape is spliced end to end and played continuously at high speed.
Digital Bin -- In cassette production, a digital audio playback device replaying sound representing both sides of a cassette repeatedly at high speed.
Slave -- A tape recorder, recording from an analog or digital bin, onto long hubs of cassette tape at high speed.
Loader -- A machine which winds cassette tape into a cassette shell, after the tape has had the audio material recorded onto it.
Dolby B -- The kind of noise reduction most commonly used with cassettes. If a tape is recorded with Dolby B, it must be played back with Dolby B. And if it is recorded without Dolby B, it should not be played back with Dolby B.
Ferric -- A kind of tape made using Iron Oxide.
Chrome -- A kind of tape made from Chromium Oxide. It has a higher maximum output level and more dynamic range than Ferric.
HX-PRO -- A system to extend high-frequency response of tape. It reduces bias (an ultrasonic signal necessary for analog recording) during periods of greater high frequencies in the recorded material in order to reduce distortion.
CD and CD-ROM Terms
CD-R -- Recordable CD. A high power laser burns inks held in the beneath the surface of a CD, causing a change of reflectivity. A lower power laser can then read the changes in reflectivity translating to ones and zeros, which ultimately represents the digital audio or data encoded on the disc. It differs from a pressed disc by the fact that on CD-R the information is stored by changing the reflectivity of ink within the disc, while pressed CDs have physical pits etched in the disc to represent the information.
Glass Master -- A master for CD Production. Pits representing the digital information on a CD are physically etched as pits in the glass. A mold is made from the glass master, in which the CD's are subsequently molded. A reflective metal layer is then added to the molded CDs, and the presence or absence of a pit changes the reflectivity of the disc to the laser reading the disc, translating to ones and zeros, which ultimately represents the digital audio or data encoded on the disc.
Glass Mastering - The process of creating a glass master, a required step in the creation of a replicated disc. It involves taking the already properly formatted and encoded information from a Red Book CD-R master or other master format and etching the pits on the glass master.
Red Book or CD-R Master -- Recordable CD with audio recorded on it according to "Red Book" specifications, which allow it to play on any Audio CD Player. Must be recorded in one continuous session, or "disc at once" mode.
PMCD -- A specific type of Red Book Master created by the Sonic Solutions Digital Audio Workstation. Also often used as a general term for any Red Book Master created specifically for use as a replication master.
Orange Book -- Another name for Recordable CD, named after the specification book of standards for the format.
CD-ROM -- A CD recorded with data file for use in a computer.
Yellow Book -- Another name for CD-ROM
CD-G -- A CD with graphical information, such as pictures or lyrics, embedded in the subchannel codes, readable by specially designed players. Most commonly used for karaoke.
Enhanced CD or ECD -- Sometimes refers to any multisession CD containing both audio and data content (see CD-Plus), but more specifically to a particular method of encoding graphical and video information, such as cover art.
CD-Plus or CD-Extra -- A Multisession CD containing Audio in the first session and data in the subsequent session. Will play audio in all CD players, but may not play data in some very early CD-ROM drives.
CD-I -- A particular for of interactive CD, not currently used much anymore.
Mixed Mode CD -- A CD containing both audio and data by putting data in the index zero "lead-in" to track one. Will play in all CD-ROM drives, but may play loud distortion in some audio CD players. Because of this, CD-Plus is preferred.
Multisession CD -- A CD containing multiple "sessions" recorded at different times. Normally multiple data sessions will not be readable by CD-ROM drives (it will see only the last). However, may be used to create CDs with both audio and data content, readable on both audio CD players and CD-ROM drives (see CD-Plus)
Hybrid CD -- A CD-ROM designed to be readable by both PC and Macintosh computers.
1630 Master - A CD Mastering Tape Format using 3/4" U-Matic tape containing both digital audio and PQ Codes for creation of a CD glass master. This was the original format for CD masters, but it is not used much anymore.
Exabyte Master -- A CD Mastering Tape Format containing both digital audio and PQ Codes as data for creation of a CD glass master. This is currently considered the most reliable CD master format. Also known as DDP
Disc-At-Once (DAO) -- A method of burning a CD-R in which the laser is never turned off or paused, so that absolutely no gaps occur in the writing of the disc. It is analogous to writing a novel in cursive while never taking the pen off the paper. Audio CD's, in order to be mass-replicated, must be written disc-at-once. Also, the audio portion of Multisession CDs must be written disc-at-once. Many CD burning programs, especially those offering both data and audio burning capabilities, and those which come "bundled" with CD Burners, can not write disc-at-once, or must be specifically set to write disc at once.
Track-At-Once (TAO) -- A method of burning a CD-R in which a portion of the CD is written, then another portion is written at a later time, even if the disc is burned all a the same time. This allows gaps in the continuous flow of information on the disc, which will cause problems with some CD players. This includes writing all of the audio first, then returning to write the Table-Of-Contents (TOC) Audio discs written track at once cannot be mass replicated without re-mastering.
TOC (Table of Contents) -- A guide, written at the beginning (inside) of a CD, telling the CD player where each track and index starts and ends.
Lead-In -- The beginning of the CD (inside) containing the Table of Contents repeated until the place where Track 1 is supposed to begin.
Lead-Out -- The portion of the disc after the end of the audio program (outside diameter of disc). This is written with unused random data in order that the outer portion does not change appearance.
Subchannel -- Codes embedded in the stream of information on a CD, identifying track number, index number, and elapsed and remaining time. Certain formats encode additional information in the subchannel.
PQ Codes -- Information encoded onto an audio CD, identifying the start and end of tracks and indexes. There are also R, S, T, U, V, and W codes, which usually go unused.
Track -- An indicator of which song you on the disc you are in.
Index -- An additional indicator, used to identify portions within a track. Although designed into the original "Red Book" audio specifications, this feature was so rarely used, that most players have dropped it from their displays and controls. It is most often used with longer classical works and on Sound Effects CDs. The gap between songs in which some players count down is specified as "Index 0", and the main track, if multiple indexes are not used, is "Index 1".
A-Time -- Time code recorded directly onto DAT tape by all current DAT recorders. A-Time is the only way to get accurate times on DAT tapes. The tape must be recorded from the beginning of the DAT, or from the end of a previously recorded section. It will not be recorded if a section of tape is skipped, so any intentional gaps in audio should be recorded silence.
EQ or Equalization -- Selective boosting or reduction of specific frequencies in an audio program.
Compression -- Reduction in level of "peak" or loud portions of an audio program, reducing its dynamic range. Usually done so that quiet portions of a recording can be made louder without making loud portions too loud to record.
Multi-Band Compression -- Separating sound into frequency ranges or "bands" and compressing each band separately before recombining them.
Limiting -- A form of compression in which the sound level is not allowed to exceed a set limit.
Expansion -- Reduction in level of quiet portions of an audio program. Usually done to reduce the apparent noise level of a recording.
De-Essing -- Reduction of high frequencies in a recording only when they become too loud. Usually done to remove overly sibilant "S" sounds from voice recordings.
Noise Reduction -- The process of reducing noise, or the listeners perception of noise, in a recording. While some systems can operate on just playback, most must be encoded on recording, and decoded on playback.
F1 -- an early digital format, using a converter to record digital audio onto a Beta or VHS video tape.
Dropout -- A momentary absence or reduction of recorded sound, usually due to a problem with the tape.
Analog -- The continuous representation of sound as an electronic voltage, or as a corresponding amount of magnetism stored on tape.
Digital -- Representation of sound as numbers corresponding to the level of an analog waveform over time.
Two Track -- A mix-down or master of a recording session.
Multi-Track -- A tape containing more than two tracks, with separate instruments or microphones recorded on separate track. It can only be played back in a recording studio. It must be mixed down to create a master suitable to use outside the studio or for mass duplication.
Dynamic Range -- The difference in level between the loudest sound recordable on a tape, and the noise floor of the tape.
Noise Floor -- The level of noise naturally occurring on a tape. No tape, even digital, is completely without noise.
Masking -- When a louder sound is played with a softer sound causing the softer sound not to be heard.
Hydrolyzed -- Older tapes can absorb moisture from the air, especially when stored in less than ideal conditions. After they've absorbed moisture they will frequently stick or shed oxide onto stationary parts of the tape player on playback. Such a tape is considered hydrolyzed.
Tape Baking -- A careful process of heating hydrolyzed tape under low heat over a long period of time to remove moisture. This makes the tape playable for a short time during which it can be re-mastered to a new tape.
Computer and CD-ROM Content Terms
ISO9660 File System -- A convention for naming files in which a file name can consist of up to 8 characters, followed by a period, followed by up to 3 characters. For example: myfile01.txt Files may need to be named under this system in order to be read properly on certain computers, or in order to be burned onto Hybrid (Mac/PC cross platform), or Enhanced CDs or CD-Extras.
Joliet File System -- The file system used by Windows 95 and above computers. It allows for long file names (up to 64 characters) which may include spaces. However, Windows is still dependent on the "extension" (the characters after the period) to understand what kind of file it is. In addition, any Joliet-named file, that is used on certain non-Windows, or pre-Windows95 systems, or is burned to a Hybrid or Multisession CD-ROM may be truncated to conform to ISO9660 naming. For instance the file: This Is My File.doc, would truncate to THISIS~1.doc
Apple HFS -- The Apple "Hierarchical File System". It allows long file names, but the file type is imbedded in the file itself, not in the name of the file. Apple files to be burned to a hybrid (dual platform) disc, should be made to conform to the ISO9660 standard in order to be compatible with, and correctly interpreted by the most computers.
Quicktime -- A Video format created by Apple. It may be used on all formats of computers.
MPEG1, MPEG2, MPEG3 --- Video Formats as defined by the "Motion Pictures Experts Group (MPEG) for encoding and compressing video into data.
MP3 -- A specific sub-definition of the MPEG video format, dealing with the storage and compression of sound. In order to save space, it employs, a "lossy" compression scheme, which, in accordance with psycho-acoustic laws, "throws away" parts of the sound, which the listener is not supposed to be able to notice. This has become a popular format for Internet delivery of music. Reactions to the format range from "can't tell the difference between MP3 and a CD" to "sounds worse than AM radio".
New Media -- A catchall phrase for web design, and interactive CD-ROM design and programming, particularly involving graphics, video, and sound.
