Glossary of Audio Terms: F - I
FADER: Used to increase or decrease volume level by a sliding potentiometer. Penny And Giles being the most popular manufacture.
FEEDBACK: A sound loop from a audio input and output. Most common example being a guitar pick up ( audio input) and speaker ( audio output) Signal from the pickup is amplified and sent to the speaker. The output from the speaker is then sent back to the pickup and re-amplified further etc.
FERRIC: Refers to iron coating materials such as magnetic tape
FET: Field Effect Transistor.
FIGURE-OF-EIGHT: Polar response of microphone that picks up audio from the front and back but rejects from the sides. Ribbon Microphones are usually figure of 8.
FILTER: An electronic circuit designed to emphasize or attenuate a specific range of frequencies.
FIREWIRE: Serial bus interface standard for high speed communications and data transfer.
FIXED POINT AND FLOATING POINT: The two categories in which digital signal processing is divided. They refer to the format used to manipulate numbers within the devises.
FLANGING: Modulated delay effect using feedback to create a dramatic, sweeping sound.
FLOPPY DISK: Computer disk that uses a flexible magnetic medium encased in a protective plastic sleeve. The maximum capacity of a standard High Density disk is 1.44Mbytes. Earlier Double Density disks hold only around half the amount of data. Early SSL console’s used the 8” size floppy.
FLUTTER ECHO: Resonant echo that occurs when sound reflects back and forth between two parallel, reflective surfaces.
FOLDBACK: System for feeding one or more separate mixes to the performers for use while recording and overdubbing. Also known as a Cue mix.
FORMATING: Is the process of preparing a storage device for use, such as a hard drive, floppy disk etc. Make sure you have any previous data backed up at least twice.
FRAGMENTATION: The process by which the available space on a disk drive gets split up into small sections due to the storing and erasing of files.
FREQUENCY: Indication of how many cycles of a repetitive waveform occur in 1 second. A waveform which has a repetition cycle of once per second has a frequency of 1Hz (pronounced Hertz).
FREQUENCY RESPONSE: A measurement of the frequency range that can be handled by a specific piece of electrical equipment or loudspeaker.
GAIN: The amount by which a circuit amplifies a signal.
GATE: An electronic device designed to mute low level signals so as to improve noise performance during pauses in the wanted material.
GENERAL MIDI: An addition to the basic MIDI spec to assure a minimum level of compatibility when playing back GM format song files. The specification covers type and program number of sounds, minimum levels of polyphony and multitimbrality, response to controller information and so on.
GLASS MASTER: Is used to punch all of data pits into a CD or DVD in replication.
GLITCH: Unwanted sound in audio signal or an unwanted error in a audio device.
GM ( GENERAL MIDI) RESET: A universal sysex command which activates the General MIDI mode on a GM instrument. The same command also sets all controllers to their default values and switches off any notes still playing by means of an All Notes Off message.
GRAPHIC EQUALISER: An equaliser whereby several narrow segments of the audio spectrum are controlled by individual cur/boost faders. The name comes about because the fader positions provide a graphic representation of the EQ curve.
GROUND: Electrical earth or 0 Volts. In mains wiring, the ground cable is physically connected to the ground via a long conductive metal spike.
GROUND LOOP ( or EARTH LOOP): Electrical wiring fault due to multiple ground connections causing audible mains hum to be picked up.
GROUP: A collection of signals within a mixer that are mixed, then routed through a separate fader to provide overall control. In a multitrack mixer, several groups are provided to feed the various recorder track inputs.
GROUND LOOP: A condition likely to lead to the circulation of currents in the ground wiring of an audio system. When these currents are induced by the alternating mains supply, hum results.
HARD DISK: Storage device used to store and receive digital information using magnetic coating rotating disks
HARMONIC: High frequency component of a complex waveform.
HARMONIC DISTORTION: The addition of harmonics that were not present in the original signal.
HEAD: The part of a tape machine or disk drive that reads and/or writes data to and from the storage media.
HEADROOM: The safety margin in dBs between the highest peak signal being passed by a piece of equipment and the absolute maximum level the equipment can handle.
HERTZ (Hz): Unit of frequency
HIGH PASS FILTER (HPF): A filter which passes high frequency signals but attenuates frequencies below its cutoff frequency.
HUM: Signal contamination caused by the addition of low frequencies, usually related to the mains power frequency.
HYPERCARDIOD: Microphone polar pattern similar to cardioid but with less sensitivity at the sides.
IC: Integrated Circuit.
IMPEDANCE: Is the measure of the opposition that a circuit presents to the passage of a current when a voltage is applied.
INDUCTOR: Is a passive electrical device employed in a electrical circuit for its property of inductance. Inductance (measured in henry) is an effect which results from the magnetic field that forms around a current carrying conductor.
INITIALISE: To automatically restore a piece of equipment to its factory default settings.
INSERT POINT: A connector that allows an external processor to be patched into a signal path so that the signal now flows through the external processor.
INSULATOR: Material that does not conduct electricity.
INTERFACE: A device that acts as an intermediary to two or more other pieces of equipment.
INTERMODULATION DISTORTION: A form of distortion that introduces frequencies not present in the original signal. These are invariably based on the sum and difference products of the original frequencies.
I/O: The part of a system that handles inputs and outputs, usually in the digital domain.
IPS: Inches Per Second. Used to describe tape speed. Common speeds being 7 1/2in/s, 15in/s and 30in/s.
ISOPROPYL ALCOHOL: Type of alcohol commonly used for cleaning and de-greasing tape machine heads and guides.