16 bit A data unit that is a maximum of 16 bits in width. 24 bit A data unit that is a maximum of 24 bits in width. A to D converter An analogue-to-digital converter (ADC, A/D, A to D) converts signals to digital numbers. Generally, an ADC converts a voltage to a certain digital number. The digital-to-analogue converter (DAC, D/A, D to D) executes the opposite procedure. Modern ADCs can currently sample up to a rate of 192 kHz (192,000 samples per second). AIFF Audio Interchange File Format Developed by Apple, based on Electronic Arts' IFF file format (Interchange File Format). The audio data in an AIFF file is not compressed and the file size is much larger than lossless (APE) and lossy (MP3) file formats. Analogue An analogue signal means any continuously variable signal. Noise in the signal is decreased electronically by shielding, good connections and cables. Attenuation The decrease of level or strength of something, for example an analogue signal. Bandwidth For an analogue signal, this is the width, measured in Hertz (Hz) of a frequency range. The bandwidth of a signal reflects how quickly it fluctuates in relation to time. So, higher bandwidth means a faster variation in the analogue signal. For a digital signal, bandwidth can also mean the quantity of data transferred over a certain time period - this is generally measured in bits per second. BPM (Beats Per Minute) The number of beats per minute in a piece of music. Typical BPMs of some music styles: Hip Hop: 70-110 BPM House: 110-140 BPM Drum & Bass: 140-190 BPM Bit A bit is the most basic unit of information used in computing, derived from 'binary digit' or 'binary unit'. Bit Rate Bit Rate is the frequency at which bits pass a certain point. It is measured in bits per second. Compact Disc This is an optical disc which stores digital audio, as stereo tracks with 16 bit coding and a sampling frequency of 44.1 kHz, and is the standard format for the majority of contemporary music. CD Mastering Mastering audio onto a Compact Disc or other physical Production Master. CD-R Compact Disc Recordable - has a standard capacity of 74 minutes of audio or 650 megabytes of data, although CD-Rs with higher capacity are widely available. Clicks Noises that occur in a section of audio. These can be caused by any of the following: unstable digital clock source, distortion in recording a track, poor mains screening or electrical crossover/improper earthing. Clipping When audio reaches a certain level, the extremities of the waveform can be caused to 'clip', meaning that an audible reduction in the dynamics of the sound can occur if the sound is being limited, or it can distort, or 'go over'. Compression Reducing the gain of an audio signal if it exceeds a preset level, thus decreasing the dynamic range of a piece of music. Best used carefully to avoid making a track sound lifeless and crushed. DAT Tape Digital Audio Tape - audio records onto these without data compression, producing a clone of the source material. Tapes range from 15 minutes to 180 minutes in length. dB / decibel A unit of measurement that quantifies the intensity of sound relative to a reference of 0 dB. (The threshold of human hearing). De-Clicking The removal of audible clicks, pops and other noises that occur in a section of audio. De-Essing Removing the transients from a vocal, or other high frequency elements of audio that are unpleasant to the ear. This can be achieved with careful application of a high pass filter or a high frequency limiter. Digital A system that operates with numbers (or binary code), through input, processing and output. For example, a Digital to Analogue converter will take the digital signal from a CD player and convert the code that makes up the digital signal into an analogue signal, which can consist of current, volts or charges, for instance. D to A converter See A to D converter. Distortion This can occur in many ways, and is often applied as an effect on guitars, for example. It is achieved by either boosting the level of the waveform to the point where clipping occurs, for a harsher sound, or through boosting the level and compressing the top of the waveform, creating a smoother sound. Distortion can also be an undesirable result of too much level on an instrument, track or song, so it is an effect that must be very closely monitored! Dithering This is used to minimise the correlated errors that can occur through quantization and re-quantization of digital data, for example when compressing data to 16 bit resolution in order to put it on a CD. Dolby The first product released by Dolby Laboratories was Type A Dolby Noise Reduction, more commonly know as Dolby A. Dolby Noise Reduction (NR) works by decreasing the dynamic range of sound during recording and increasing it during playback. There are several other trademarked Dolby sound systems, such as Dolby Digital and Dolby Stereo. Dropout A temporary drop in signal level or audio volume, or overall sound of a section of audio. Dubplate DVD Digital Versatile Disc. These have the same dimensions as an ordinary Compact Disc, but they are able to hold a larger amount of information due to being encoded at a far greater density. DVD-Audio (DVDA) is the format of any audio that is placed upon a DVD, and can range from mono to 5.1 surround sound. Dynamics The volume of a note or a sound, from its lowest to highest range. In written music the symbols are f (forte) for loudness and p (piano) for quietness. Editing Changing a song or a segment of it, by removing/adding sections. For example, removing swear words and overlaying the instrumental version in the gaps to make a track suitable for the radio! Equally, removing sections of the track and piecing together the remainder, making sure it flows in time and that the edit points are unnoticeable to the ear. EP Extended Play - is it a single? Is it an album? No, it's an EP! These are sometimes extended singles with a few extra tracks on, ranging from 15 to 35 minutes in length, and are often released as demos, samplers to forthcoming albums, or as a collation of material to be released between albums. EQ/Equalization The dictionary tells us that this is 'the art of making equal'. Experience tells us that there's a lot more to it! In mastering terms, equalization means adjusting the various frequencies that constitute an audio signal through the use of various different equalizers, such as peak, shelf and graphic equalizers. To save filling the whole page with EQ theory, we'll let you find out for yourself by listening to how we can improve your music through equalization, amongst other things! Exabyte A unit of information equal to one quintillion bytes...and the company who manufacture Exatape, an 8mm digital tape that is used as a for a CD Production Master. 'Exabyte' has wrongly been adopted as the name for the actual physical tape, much like 'Hoover' for vacuum cleaners, and 'Tannoy' for a Public Address System! Ironically, nobody has yet created a tape that can hold a full Exabyte itself. FTP File Transfer Protocol A system for transferring any type of file, generally through a web browser with the prefix ftp://. Filter A means of processing sound, often by way of only altering certain frequencies within an entire audio signal. Filters can exist in various forms, such as a knob on a keyboard, a sound effect, or an Equaliser. One of the more common applications in mastering is that of a cut/pass filter. For example, a low cut at 40hZ filters out frequencies below 40hZ. Glass Master A glass plate onto which the master data is transferred during mass replication. This is taken from any available CD Master, such as a Red Book CD or Exabyte. Graphic Equalizer A form of equalizer consisting of several band pass filters, typically within the frequency range of human hearing (20hZ to 20kHz). Each band is at a set frequency with its own gain control, as opposed to a parametric equalizer which has variable frequency controls, gain controls and bandwidth settings. Headroom The difference between the maximum output of an audio signal and the level at which it is compressed or distorted. Hz The unit of frequency. One Hertz (Hz) means an event occurs once a second. An audio signal with a sampling frequency of 44.1 kHz (kilohertz) means that the audio is sampled 44,100 times per second. KHz A multiple of Hz (Hertz). 1kHz is equal to 1000 Hertz. Level The amplitude of a song, instrument or other element of a piece of music. In mastering an album all songs will need to have their levels matched so that there are no tracks that are too quiet or loud. Limiting Ensuring that an audio signal does not exceed a certain level. A brick wall limiter has a preset amplitude that is never exceeded, whereas a peak limiter will only have an effect if its threshold is set to a point where sections of the audio reach that level. Similarly, a high frequency limiter (or de-esser) will only limit high frequencies after a preset point. Mastering The art of processing and transferring recorded music onto a physical format to be used for mass production. This process goes through various stages, depending on the nature of the original audio, and involves equalisation, compression, editing, limiting, vinyl cutting, CD mastering and many other elements besides. Mastering Engineer A mythical warrior of music, wandering the gloomy caverns of time with only his ears to protect him against the wave of crushed, dynamically deficient noise that comes from the distant land they call 'America'. Or a person who sits in a studio and makes your music sound better. You decide! Monitors Speakers that are set up to enable the engineer to hear changes made to the audio during the mastering process. Also in any stage of music production/performing, the speakers that enable the performers to be able to hear what they are doing! Mono A monaural (single channel) format of sound. If being played through two monitors, the signal will generally be routed in such a way that it will sound like it is coming from directly between the two speakers. MP3 A common format of digital audio, compressed to reduce the amount of data needed to represent the audio. This generally means a cut of highest and lowest frequencies, although variations of quality can occur depending on the amount of compression. Noise Undesirable sound on a recording of music. Examples are hum (often machine noise/electrical crossover) and hiss (white noise or even a result of a noisy recording environment). Normalizing The application of a constant amount of gain to a piece of music in order to bring the audio up to a specified level. This is designed to produce maximum volume with minimum distortion, but can regularly reulst in clipping of the audio signal. EMasters do not normalize anything. Patch Bay An Inputs and Outputs board where all pieces of equipment in the studio can be connected and disconnected easily for a variety of paths for an audio signal. PQ Code Data on a CD master that contains information such as track IDs, ISRC codes and barcode. Production Master A physical format such as CD or Exabyte that contains audio and PQ data and is therefore fully prepared for manufacture. Remastering In short, mastering again! This is generally done from the original masters so that the engineer is working on unchanged material. For example, when Kevin remastered the Queen back catalogue, he had to search for the original analogue reels in an underground vault, then spent 6 months working on remastering about a dozen albums from the original tapes! Sampling Frequency The rate at which an audio signal is sampled per second, measured in Hertz. Session A period of time during which a mastering project is carried out. An attended session is where a person or people involved with the project come into the studio to participate (to a certain degree) in the mastering process. Stereo Stereophonic sound - a two channel audio signal that uses a pair of speakers designed to simulate the natural hearing of the ear. As opposed to mono, a stereo signal can contain sounds individually in either channel, thus giving the impression of sounds coming from variosu different directions. Surround Sound An expanded sound format consisting generally of six channels - three speakers at the front (left, centre, right) two rear speakers (left, right) and a low frequency channel usually in the form of a subwoofer. This has become a common format for live recordings on DVD as a way of creating a better impression of a live atmosphere in the listening experience. Vinyl In the context of mastering, a vinyl refers to an analogue disc that consists of grooves which, when played by a stylus or needle, play back the audio signal that was cut into the surface a vinyl lathe. Vinyl Cutting The art of transferring audio onto a vinyl disc. This can be done either onto a lacquer (which is the vinyl equivalent of a CD master and is used for mass production) or onto an acetate/dubplate (which is the vinyl equivalent of a CD listening copy). Sometimes the audio will need to be cut at 33rpm or 45 rpm, depending on the length of the song, the size of the disc, or the preference of the artist/record company. Vinyl Lathe The machine used by the mastering engineer to cut vinyl from an audio signal. The lathe in the eMasters studio is a customised Neumann VMS 82 lacquer lathe and is one of very few similar lathes in the country. Vinyl Mastering Simply, the mastering of audio onto a vinyl production master or acetate. The size and speed of the vinyl will need to be decided depending on the length of a track, due to the amount of space on vinyl being limited. There are so many other variations and aspects of vinyl mastering and cutting that there's nowhere near enough space to list them here! VU Meter Volume Unit Meter - used to display an analogue signal, and it looks nice too... WAV The standard audio file format for Microsoft and IBM computers, very similar to AIF in that it contains uncompressed audio. Waveform The visual representation of an audio signal. A good waveform display aids activities such as editing and de-clicking. Wavelength The distance in a sound wave between adjacent peaks. Word Clock A machine used to synchronise other devices through bit rate.