F1. A two-track recording format that stored digital audio on Beta or VHS videotape.

factory preset. A program or patch created for a synthesizer, effects processor, or other device by the manufacturer and included with the device when it ships. In some cases, factory presets are stored in ROM and cannot be changed; in others, they are stored in RAM and can be modified by the user. Factory presets are intended to provide the user with a working library of useful sounds as well as a set of sounds that show off the capabilities of the device to potential purchasers in stores.

fade in. A gradual increase in volume level, starting from silence. See Figure F.1.

Figure F.1. Most DAWs provide a fade function that can fade an audio file in and out.

fade out. A gradual decrease in audio level, ending at silence. See Figure F.1.

fader. Another name for a potentiometer, though most engineers use the term to refer to a volume control that slides in a linear fashion instead of turning in a rotary fashion. Faders are typically used in mixers.

fader flip. 1. A function of some analog mixers that have two input signal paths and faders per channels. (Often one path is the regular input path, and the other path, with a smaller fader, is used as a tape return for bringing recorded signals from a multi-track tape machine into the mixer.) Fader flip reverses which signal path is using the main faders and which is using the “small” secondary tape return faders. 2. A function found in many digital mixers that allows one set of faders to control additional channels or other functions in the mixer.

fader group. A function of some mixers that can link the operation of faders so they move together—when one fader in the group is moved, the rest of the faders follow along, maintaining the relative differences in their settings.

fall time. The time it takes for a signal or voltage to change from a high value to a low value, typically measured as the time it takes to go from 90% to 10% maximum level.

FAQ. Frequently Asked Questions. A feature of the documentation or support web pages for a device that lists and answers common questions from users.

far field. Speakers or a sound source placed beyond the near-field range (more than three to four feet or so from the listener). Far-field speakers typically are substantially larger and more powerful than near-field monitors and are more influenced by room acoustics, reflections, and reverberations.

Faraday shield (a.k.a. Faraday cage). A type of electromagnetic shield named for physicist Michael Faraday and created by placing grounded conductive material, such as copper or aluminum, around the object being shielded. Faraday shields are used in a variety of applications, such as around MRI machines, microwave ovens, and others. In audio, one example of a Faraday shield is the shielded wire used in coaxial cables; shields are also used around a variety of sensitive electronic components and circuits.

fast forward. A transport control that causes a tape to fast-wind toward the end of the tape or a DAW or audio program to quickly scroll toward the end of the song or project.

Fast Fourier transform (a.k.a. FFT). An efficient algorithm for calculating a Fourier transform. See also Fourier transform.

FAT. File Allocation Table. A file stored in Sector 0 on a disk or other media containing information about the media, which areas of the media are unused and which contain data, and where each file is stored. See also sector.

FAT-32. A type of file allocation table that supports drives larger than two gigabytes in size. See also FAT.

feathering. A technique in which equalization is spread out over a range of frequencies rather than focused on a single frequency. For example, instead of a large boost at 500 Hz, a small boost is added at 500 Hz, a smaller boost at 480 and 520 Hz, a still smaller one at 460 and 540 Hz, and so on.

feedback. 1. A problem caused by the sound from a speaker entering a microphone, being amplified, coming out of the speaker, being picked up by the microphone, being amplified, coming out of the speaker...a loop occurs, resulting in a runaway signal at a particular frequency and the familiar howl or squeal of feedback. See Figure F.2. 2. A runaway signal that results when the output of a device is inadvertently connected to its input, resulting in screaming out-of-control frequencies. 3. Also known as regeneration. With an echo or delay device, a portion of the echo output being sent back to the input of the processor, where it is delayed again, producing an additional repeat. The amount of feedback determines the number of echo repeats that are heard. 4. With a modulation device, such as a flanger or phase shifter, a portion of the output signal that is sent back to the input of the device, resulting in a more intense effect. 5. A guitar performance technique where an electric guitar’s strings vibrate in response to high volume levels from its amplifier, causing infinite sustain and the emphasis of different harmonic frequencies.

Figure F.2. Feedback results when a signal loops repeatedly through a device or system, increasing in intensity until it is out of control.

feedback eliminator. A device that combines a spectrum analyzer and notch equalizer that can automatically detect acoustic feedback and adjust the equalizer to reduce the level of the frequency that is feeding back.

ferrofluid. An oil-like substance that contains magnetic material. Ferrofluid is used in speaker drivers to draw heat away from the voice coil, allowing the coil to handle more power.

FET. Field-Effect Transistor, a.k.a. Unipolar Transistor. A type of transistor that uses an electronic field between the substrate layers in the semiconductor material to control voltage. FETs have linear response and high input impedance, making them ideal for microphone electronics and for power amps, among other things. See also transistor, JFET, MOSFET.

FFT. See Fast Fourier transform.

Fibre Channel. A network technology standardized by ANSI and used for storage systems, including SANs (Storage Area Networks). Fibre Channel offers high-speed connections for hard drives, RAIDs, and other storage devices. Fibre Channel and SANs are usually used by large production installations in which multiple operators require access to the same information and drives.

FIFO. First In, First Out. A computer data storage and processing paradigm where the first data to enter a buffer or other memory is the first to be read, processed, and output.

figure 8 (a.k.a. bi-directional). A microphone polar pattern resembling a sideways “8” shape (see Figure F.3). Figure-8 microphones are bi-directional, picking up sound nearly equally well from the front and from the rear, and not at all from the sides of the mic. Figure-8-patterned microphones are mainly used for studio applications, where they can be positioned to reject sound from the side, but still pick up ambience from the rear. They are less commonly used for live applications, as the rear lobe makes them susceptible to feedback problems. Figure-8 microphones, like all directional microphones, are subject to proximity effect. See also pressure-gradient microphone.

Figure F.3. A figure-8 polar pattern consists of two spherical pickup lobes, one in front of the microphone and the other behind it.

filament. A short tungsten wire in a vacuum tube that is used to heat up the cathode to make it easier for electrons to cross to the anode.

file. A collection of computer data stored on a drive or other media. There are a variety of types of files: data, program, directory, and more.

file path. The location of a file on a computer hard drive. The path describes all the steps that are necessary to navigate through nested folders and directories to find the file. For example, Macintosh HD/Applications/Digidesign/Pro Tools/Pro Tools LE would tell the user or computer to look in the hard drive named Macintosh HD, inside the Applications folder, which contains the Digidesign folder, which contains the Pro Tools folder, which contains the Pro Tools LE program file. Paths can be very simple or very long and complex, depending on how many folders are nested together.

file server. See server.

filter. A type of audio processor that reduces or attenuates the level of a range of frequencies. In many cases, a filter is combined with an amplifier so that frequencies can be boosted as well as cut. A number of filters can be combined into one device or processor to create an equalizer. There are a variety of types, including:

filter slope. See slope.

filter sweep. A technique in which the cutoff frequency of a filter is increased or decreased in real time, while the filter is passing signal. The sonic effect depends on the type of filter being swept and the amount of filter resonance applied.

finalize. 1. Also known as fix-up. The process of converting an Orange Book CD into a closed Red Book–compatible CD. 2. A mastering-style process taking its name from the TC Electronic Finalizer family of digital audio devices, which provide equalization, compression/limiting, and other processes used in mastering stereo mixes.

fine. The opposite of coarse. Fine refers to small increments of change or measurement, usually in reference to a control or parameter movement.

fingerprint EQ. A type of digital equalizer that analyzes the frequency spectrum of one signal, then applies that spectrum to another signal.

FIR filter. Finite Impulse Response filter. A type of digital filter that uses the average of several samples to create its output. Because they do not cause phase distortion, FIR filters are used for critical applications, such as anti-aliasing and anti-imaging applications in analog-to-digital and digital-to-analog converters. See also IIR filter.

FireWire (a.k.a. IEEE 1394). A serial communication protocol developed by Apple and now available in a wide variety of professional and consumer audio and video equipment. FireWire supports asynchronous and isochronous transfers, allows up to 63 devices per bus, and is hot-swappable. FireWire does not require communication through the CPU or system memory. There are several types, including emerging standards that are not yet in widespread use. FireWire hard drives have become a popular choice for data storage and recording in studios.

firmware. Basic software and instructions for a device that are stored in one of several types of ROM or programmable ROM chips or in flash memory. Firmware is used to load the operating system (occasionally the OS may be stored as firmware) and contains other instructions necessary for the device to set up and operate.

first reflection. Sound waves that reach the listener’s ears after one bounce from a surface, less than 20 milliseconds after the direct sound from the source. First reflections are often the most destructive in terms of acoustic cancellations and reinforcements in a room. See Figure F.4.

Figure F.4. A first reflection is a sound wave that reaches the listener immediately after the direct sound, after reflecting off of one surface.

fixed pattern. A microphone that has a single polar pattern.

fixed point. A computer number and math system that has a set number of digits after the decimal point. For example, if the system has two digits after the decimal point, numbers such as 1.15 can be accurately represented. However, a disadvantage is that a number such as 1.0143 would have to be rounded to 1.01. See also floating point.

FLAC. Free Lossless Audio Codec. A lossless open-source audio data compression/decompression file format. FLAC can result in file size reductions up to 50% without loss of data.

flam. 1. A percussion technique in which a grace note is played immediately before the actual note. 2. Two identical sounds that occur very close together in time. Depending on the time difference between them, this can produce a “doubled” effect or can result in phase cancellation.

flange. The rim, or sides, of a tape reel, which attach to the reel’s hub.

flanging. An effect created in the 1960s using two analog reel-to-reel tape decks playing back the same audio slightly out of sync. The signals were mixed together, and the speed of one of the decks was changed by pressing on its tape reel flange, creating a continuously moving comb-filter cancellation and reinforcement. Analog and digital electronic versions of the effect have been created, which allow for greater control over the effect—as well as portability! See also through-zero flanging.

flash. See flash RAM.

flash drive. A drive that records to flash memory. See also jump drive.

flash memory. See flash RAM.

flash RAM (a.k.a. flash memory, FEPROM [Flash Erasable, Programmable, Read-Only Memory]). A type of RAM (Random Access Memory) that retains its contents when power is removed. Flash RAM can be written and read by a computer or other device, just like a hard drive or other storage media. A variety of forms are available, including flash drives and others.

flat. 1. Having an even frequency response, without dips or peaks due to electronic or physical characteristics. 2. A device or room in which all frequencies are outputted at unity gain—that is to say, at the same output level as they came in. Since a flat device or room doesn’t emphasize or deemphasize any frequencies, it provides a true picture of the signal that will translate well to other systems and rooms. 3. Setting all the boost/cut controls on an equalizer to zero so there is no change to the signal.

flat response. A device that outputs all the frequencies in a signal at the same level they were at when the signal was inputted.

Fletcher-Munson Curve (a.k.a. equal-loudness contours). A series of response curves developed by American physicists Harvey Fletcher and W. A. Munson to show the human ear’s response to frequencies at different volume levels.

float. To suspend the floor of a studio on hard rubber “pucks,” springs, or other material to isolate it from the rest of the structure. 2. An unconnected electrical ground. An example is a telescoping shield.

floating floor. A studio floor that is isolated from the surrounding structure.

floating point. A technique used to represent large numbers in computers. There are three parts to a floating-point number: the sign (positive or negative), the mantissa (the value represented as a fraction), and an exponent (indicates the position of the decimal point). For example, 192,000 would be represented as 1.92 times 10 to the power of five. This type of representation allows computers to very efficiently process data, especially for DSP and other operations. Floating-point math and value representation are also used in DAWs to increase headroom for certain operations. See also fixed point.

floating window. A window in a computer program that always remains on top of the program’s other windows. Examples might include a tool palette, a video playback window, or another window that needs to remain visible and accessible at all times.

floppy disk. A type of data storage medium using a thin Mylar disk encased in a plastic envelope or shell. A variety of sizes and capacities were introduced over the years. Floppy disks have been replaced by flash drives, CD-RWs, and other more durable media with higher storage capacities.

flutter. A fast variation or fluctuation in the playback speed of a tape recorder, resulting in an audio artifact resembling vibrato. See also wow.

flutter echo. A fast echo effect cased by sound waves bouncing between two parallel hard surfaces in a room and creating fast, discrete echoes. The resulting effect is a very short “rattling” type of echo often described as fluttering.

flux. 1. Magnetic energy, measured in webers or nanowebers. 2. A gel-like substance used during soldering to lower the melting temperature of the solder.

FM. See frequency modulation.

FM synthesis. Frequency Modulation synthesis. A type of digital synthesis developed by John Chowning and first utilized by New England Digital for the Synclavier and Yamaha for the DX7. FM synthesis uses one or more oscillators to modulate one or more audible oscillators. The audible oscillators are called carriers, while the oscillators used to produce modulation are called modulators. Early types of FM oscillators (called operators) produced only sine waves, but through intricate modulation routings were capable of creating extremely complex waveforms. Later synthesizers built upon the FM concept allowed the use of operators producing additional waveforms. FM synthesizers are quite flexible, but are especially adept at producing bell-like tones.

foil shield. A type of shielding used in some cables, in which a metal foil (usually aluminum) is used in place of braided strands of wire. Foil shielding provides more complete coverage and therefore better shielding than stranded types.

foldback (a.k.a. monitor system). A system that is intended to feed a mix back to the musicians in a studio or onstage so they can hear themselves and each other while recording or playing.

fold down. Reducing a multichannel surround mix to a smaller number of channels, such as stereo.

folder. A graphical representation of a computer directory. A computer folder is analogous to a physical folder that is used to store paper documents, except that virtual folders are used to store computer files.

foot pedal (a.k.a. expression pedal). A foot-operated control device—often a rocking platform that turns a potentiometer. Foot pedals are used to control volume and continuous controllers with keyboards and to control certain parameters in effects processors and other devices.

footswitch. A switch that is designed to be operated by foot. Footswitches are used for a variety of purposes, but are mainly used to bypass and enable effects processors during live performance.

formant. A resonance produced by a vocal tract or other sound generator—the formants in a voice or instrument are what make it identifiable. The formants remain the same regardless of the pitch or frequency the sound generator is creating. Since manufacturers started providing formant processing in devices and plug-ins that transpose or shift pitch, much more realistic-sounding results have been possible.

format. 1. The “type” of a file—the file format—describes the protocol used to write the data. 2. To format a disk or other media is to prepare it for use with a particular operating system. There are two types of formatting, low level (usually handled by the drive manufacturer) and high level (which is done by the end user). 3. The particular host protocol that a software plug-in conforms to; examples include RTAS, VST, MAS, and Audio Units.

formatted capacity. The amount of storage space available on a drive after it has been formatted. The advertised capacity of many hard drives is the unformatted capacity, which looks better since it is bigger. But the formatted capacity is a far more useful spec because it reveals how much actual space is available for storing data.

Fourier analysis. A mathematical method named for French mathematician Jean Baptiste Joseph Fourier for analyzing the frequency spectrum of a waveform. See also Fast Fourier transform, Fourier transform.

Fourier transform. A mathematical method for analyzing a waveform that allows for transfer between the time and frequency domains. In audio, a Fourier transform is based on the fact that audio waveforms can be represented as the sum of many component single-frequency waves (sine waves). A Fourier transform is both the graph showing the frequency content of a waveform and the mathematical equation that can be used to represent it. An inverse of the Fourier transform can be used to synthesize the sound that was analyzed.

FPU. Floating Point Unit. A “coprocessor” or supplemental processing chip in a computer dedicated to handling and speeding up floating-point math operations.

fragmentation. As a computer writes, erases, and rewrites data onto a hard disk, areas appear on the disk where no data is stored. When new data is written, it will fill in the existing holes first, sometimes breaking up a single file into multiple parts spread across different locations on the drive. This is called fragmentation. Fragmentation can be a problem when it becomes so widespread that the drive mechanism is forced to constantly jump around to find all the parts of each file, significantly slowing down the read process. Various disk utilities can be used to defragment, or defrag, a drive to restore its performance.

frame. A single image in a video or film. SMPTE time code represents each frame in a video or film with one word of data, indicating an exact time location.

frame accurate. A device or system that synchronizes with timing accurate to the frame level.

frame rate. The speed of the time code, usually expressed in frames per second (FPS). A number of rates are in common use, including 25, 29.97 drop frame, and 30 FPS. Note that the time code frame rate is not related to the tempo of the music. Rather, it is a timing constant for synchronized gear to reference.

free field. An area with no reflective surfaces. The only true free field space is outer space, since even outdoors the earth causes reflections.

free space. See free field.

freeware. Software created by an individual and offered for free download. Freeware is copyrighted, though the author requests no payment or licensing fees. See also shareware.

freewheel. A function of some time code readers that can continue to operate as if locked to time code even if the incoming time code signal is interrupted.

freeze. A function of some DAWs that renders a virtual instrument or audio track using real-time plug-ins to an audio file in order to free up the system’s DSP resources. Once a track is rendered or frozen, it plays from hard disk instead of consuming CPU power for real-time processing. In most cases the track can be unfrozen in order to make changes to it, then re-frozen at any time.

frequency. The number of times a sound wave vibrates, or moves through a complete cycle, in a second.

frequency doubling. A phenomenon caused by harmonic distortion that makes a low-frequency signal seem to sound an octave higher than it actually is.

frequency modulation (a.k.a. FM). A technique for modulating an audio waveform’s frequency (the carrier) with another audio waveform (the modulator). The most common audio example is vibrato, where a low-frequency signal is used to slightly change the pitch of another signal, creating a wavering pitch. Frequency modulation is used to encode a signal for radio broadcast and is used in various types of synthesis—in particular, FM synthesis.

frequency range. The span of frequencies a device can reproduce.

frequency response. 1. How a device or space responds to a range of frequencies. 2. Maximum and minimum frequencies a device can pass with full level.

frequency response curve. A graph of the difference in the output amplitude of the range of frequencies versus the input amplitude of the range of frequencies when passed through a device. In other words, a graph of how well a device reproduces the range of frequencies. A flat frequency response curve indicates that the output amplitude of a given frequency will be the same as the input amplitude of the same frequency. See Figure F.5.

Figure F.5. A frequency response curve is a graph of how well a device reproduces the frequency range. In this case, a microphone manufacturer has provided two curves, one (solid line) for the normal response, and the other (dotted line) for the microphone with low-frequency roll-off engaged.

frequency sweep. See sweep.

front address. See end address.

front loaded. A speaker cabinet in which the driver is mounted on the front of the cabinet, on a baffle. See also horn loaded.

front side bus. See FSB.

Fs. Frequency, Sampling, a.k.a. fs, FS, fS. An abbreviation for sampling rate.

FSB. Front Side Bus. A data bus that connects a computer’s CPU to its RAM, motherboard, and other items. The FSB is critical to the speed of the system because it is responsible for shuttling virtually all of the data in the system to and from the CPU.

FSK. Frequency Shift Keying. A system that uses an audio frequency modulated by a square wave to represent data as well as for synchronizing some sequencers and drum machines to other gear. Other systems that use FSK include modems and fax machines.

full code. See full scale.

full duplex. A circuit that is able to send and receive data at the same time. Computer audio systems are said to be full duplex if they can record and play audio simultaneously.

full normal. A type of normal connection in a patch bay in which a signal fed into the top back jack of the bay will be automatically connected to the bottom back jack of the bay. Plugging a cable into either the front top or front bottom jack will break the “normal” connection, allowing the signal to be re-routed. See also normal.

full range. Technically, a speaker that is able to reproduce the entire audio frequency range, though in practice, the actual range will be somewhat limited at the high and low ends.

full scale. The highest signal level that can be represented by a digital system, where all the bits in a sample word have a value of one. A signal of any higher level will result in clipping.

full track. A tape recorder head format in which a single monophonic channel covers the entire width of the tape.

function generator. An electronic device used to generate waveforms, such as triangle or sine waves, at various frequencies. Function generators are used to provide signals to test and analyze other equipment.

fundamental. The base, core, or primary frequency of a pitched sound. The fundamental is almost always the lowest-frequency component of a given sound.

fuse. An electronic component designed to protect a device from damage or fire by failing if the amount of electrical current exceeds a certain point.

fuzz. A buzzy, highly distorted effect often used with electric guitar.

FX. Short for effects.

FX return. See effects return.

FX send. See effects send.