W
Wavelength
The distance the sound wave travels to complete one cycle. The distance between one peak or crest of a sine wave and the next corresponding peak or crest. The wavelength of any frequency may be found by dividing the speed of sound by the frequency. (Speed of sound at sea level is 331.4 meters/second or 1087.42 feet/second).
WDM driver (Windows Driver Model)
32-bit driver architecture for Windows. MIDI interfaces and audio hardware that run on Windows 2000 WDM drivers.
Woofer
A speaker, (driver), used for low-frequency reproduction. Usually larger and heavier than a midrange or tweeter.
X
XLR
A type of connector used for balanced lines. Used for microphones, balanced audio components and the AES/EBU digital connection.
Friday, November 2, 2007
U-V
U
Unity gain:
A circuit with unity gain will not increase or decrease the volume level.
USB (Universal Serial Bus)
An easy way to connect external computer accessories such as MIDI interfaces and audio hardware, among others.
USB port
Connector designed to take USB-enabled devices.
V
Vb
The total box volume, usually in cubic feet or liters. Used specifically in sealed and ported designs.
Vf
The front volume of a bandpass design.
Vr
The rear volume of a bandpass design.
Velocity Engine
Additional arithmetic unit in the G4 processor. It does require special support on the part of music software, but given this support, it boosts performance markedly.
Verse
The more subdued musical passages between refrains or choruses.
Voice coil
The wire wound around the speaker former. The former is mechanically connected to the speaker cone and causes the cone to vibrate in response to the audio current in the voice coil.
Voicing
The process of shaping a signal's characteristic tone, that is the relative intensity of its low, middle and high frequency components.
VST Instruments
Software sound generators that are plugged into a sequencer. The sounds of VST instrument are computed by the computer in real time.
Unity gain:
A circuit with unity gain will not increase or decrease the volume level.
USB (Universal Serial Bus)
An easy way to connect external computer accessories such as MIDI interfaces and audio hardware, among others.
USB port
Connector designed to take USB-enabled devices.
V
Vb
The total box volume, usually in cubic feet or liters. Used specifically in sealed and ported designs.
Vf
The front volume of a bandpass design.
Vr
The rear volume of a bandpass design.
Velocity Engine
Additional arithmetic unit in the G4 processor. It does require special support on the part of music software, but given this support, it boosts performance markedly.
Verse
The more subdued musical passages between refrains or choruses.
Voice coil
The wire wound around the speaker former. The former is mechanically connected to the speaker cone and causes the cone to vibrate in response to the audio current in the voice coil.
Voicing
The process of shaping a signal's characteristic tone, that is the relative intensity of its low, middle and high frequency components.
VST Instruments
Software sound generators that are plugged into a sequencer. The sounds of VST instrument are computed by the computer in real time.
S-T
S
Sampling CD
Sound library in which digitized musical phrases, drum loops, vocal recordings, instruments or natural sounds are archived for use in self-produced songs.
SCSI (Small Computer Systems Interface)
This standard interface serves to connect hard disks and end devices such as scanners or samplers to the computer.
Sealed enclosure:
An air tight enclosure that completely isolates the back wave of the driver from the front. Very tight, defined sound (with Qtc = 0.707) with very good transient response and power handling.
Send effect
An effect that is applied to several tracks at the same time.
Sensitivity:
A measurement of how much power is required for a loudspeaker to achieve a certain output level. The general standard used is on-axis SPL(Sound Pressure Level) at 1 watt input, 1 meter distance.
Sequencer
Music software application for creating, editing and arranging music to create finished songs.
Signal-to-noise (SN) Ratio:
The range or distance between the noise floor (the noise level of the equipment itself) and the music signal.
Sine wave
The waveform of a pure alternating current or voltage. It deviates about a zero point to a positive value and a negative value. Audio signals are sine waves or combinations of sine waves. The waveform of a pure alternating current or voltage. It deviates about a zero point to a positive value and a negative value. Audio signals are sine waves or combinations of sine waves.
Single-ended
Type of amplification often, (but not always), using vacuum tubes. Typically low power output, low damping factor and relatively high distortion. Single-ended enthusiasts claim that the sound quality is more "real".
Song tempo
Describes the speed at which the notes of a song are played. Largely dictated by the choice of musical style, tempo is indicated in BPM.
Sound generator
Device or software that produces sounds suitable for use in musical applications.
Sounds
Generic term that in this term describes the auditory effects produced by instruments.
Sound Pressure Level (Spl):
Given in decibels (DB) is an expression of loudness or volume. A 10db increase in SPL represents a doubling in volume. Live orchestral music reaches brief peaks in the 105db range and live rock easily goes over 120db.
Soundstage
A listening term the refers to the placement of a stereo image in a fashion that replicates the original performance. A realistic soundstage has proportional width, depth and height.
Sound Waves
Sound waves can be thought of like the waves in water. Frequency determines the length of the waves; amplitude or volume determines the height of the waves. At 20Hz, the wavelength is 56 feet long! These long waves give bass its penetrating ability, (why you can hear car boomers blocks away).
Speaker Level
Taken from the speaker terminals. This signal has already been amplified.
Spectral balance
Balance across the entire frequency spectrum of the audio range.
Standing wave
A buildup of sound level at a particular frequency that is dependent upon the dimensions of a resonant room, car interior, or enclosure. It occurs when the rate of energy loss equals the rate of energy input into the system. This is what you hear when you listen into a sea shell.
Stereo
From the Greek meaning solid. The purpose of stereo is not to give you separate right and left channels, but to provide the illusion of a three-dimensional, holographic image between the speakers.
Step sequencer
A device or software function that facilitates the process of coming up with melody lines or rhythmic phrases intuitively by experimentation.
Studio equipment
All the gear in a music studio. This includes mixers, effects and synthesizers and a bunch of other fun toys.
Studio environment
The entirety of all devices required for a musical production, for example, mixers, instruments and effects.
Subwoofer
A speaker designed exclusively for low-frequency reproduction. A true subwoofer should be able to at least reach into the bottom octave (20-40Hz). There are many "subwoofers" on the market that would be more accurately termed "woofers".
Surround (suspension)
The outer suspension of a speaker cone; holds the diaphragm in place but allows it to move when activated. Usually made of foam or rubber.
Surround Sound
Sound extracted from the stereo signal sent to smaller rear or side speakers used in a home theater.
Synthesizer
An electronic musical instrument that generates sounds unobtainable from ordinary musical instruments. It can be manipulated in variety of ways.
T
THX
Refers to a series of specifications for surround sound systems. Professional THX is used in commercial movie theaters. Home THX specifications are not published and manufacturers must sign non-disclosure waivers before submitting their products for THX certification. Manufacturers that receive certification for their products must pay a royalty on units sold.
Timbre
The quality of a sound that distinguishes it from other sounds of the same pitch and volume. The distinctive tone of an instrument or a singing voice.
Timbral
Refers to the overall frequency balance of a system. In a perfect world, all systems would have complete tonal neutrality. With current technology, this ideal is approached but not met. Listening to many equally "good" speakers will reveal that some sound warmer than others, some sound brighter etc... In a surround sound system it is important that all speakers have a close timbral match for the highest degree of sonic realism.
Toolbox
Menu containing editing tools for arranging and editing audio and MIDI editors.
Total harmonic distortion (THD)
Refers to a device adding harmonics that were not in the original signal. For example: a device that is fed a 20Hz sine wave that is also putting out 40Hz, 80Hz etc. Not usually a factor in most modern electronics, but still a significant design problem in loudspeakers.
Tracks
Tracks contain the individual musical elements and MIDI or audio data.
Transducer
A device that converts one form of energy to another. Playback transducers are the phono cartridge, which changes mechanical vibrations into electrical energy, and the loudspeakers, which change it back, from electrical energy coming from the amp to mechanical movement of the diaphragm, causing audible pressure changes in the air.
Transmission Line
Also referred to as a T-line. A type of bass cabinet in which the back wave follows a relatively long, usually damped path before being ported to the outside. T-lines are usually rather large and costly cabinets to manufacture. Opinions vary widely over the "best" type of bass cabinet, but much has to do with how well a given design, such as a transmission line is implemented.
Transient response
The ability of a component to respond quickly and accurately to transients. Transient response affects reproduction of the attack and decay characteristics of a sound.
Transparency
Listening term. An analog that can be best "pictured" in photography. The more "transparent" the sound, the clearer the auditory picture.
Transients
Instantaneous changes in dynamics, producing steep wave fronts.
Transport bar
Central control panel of a sequencer. Among other things, it lets you start record, play back and navigate through the arrangement.
Tuning Frequency
The helmholtz resonant frequency of a box. Also refers to the resonant frequency of other types of systems.
Tweeter
A speaker, (driver), used to reproduce the higher range of frequencies. To form a full-range system, a tweeter needs to be combined with a woofer, (2-way system), or a woofer and midrange, (3-way system).
Sampling CD
Sound library in which digitized musical phrases, drum loops, vocal recordings, instruments or natural sounds are archived for use in self-produced songs.
SCSI (Small Computer Systems Interface)
This standard interface serves to connect hard disks and end devices such as scanners or samplers to the computer.
Sealed enclosure:
An air tight enclosure that completely isolates the back wave of the driver from the front. Very tight, defined sound (with Qtc = 0.707) with very good transient response and power handling.
Send effect
An effect that is applied to several tracks at the same time.
Sensitivity:
A measurement of how much power is required for a loudspeaker to achieve a certain output level. The general standard used is on-axis SPL(Sound Pressure Level) at 1 watt input, 1 meter distance.
Sequencer
Music software application for creating, editing and arranging music to create finished songs.
Signal-to-noise (SN) Ratio:
The range or distance between the noise floor (the noise level of the equipment itself) and the music signal.
Sine wave
The waveform of a pure alternating current or voltage. It deviates about a zero point to a positive value and a negative value. Audio signals are sine waves or combinations of sine waves. The waveform of a pure alternating current or voltage. It deviates about a zero point to a positive value and a negative value. Audio signals are sine waves or combinations of sine waves.
Single-ended
Type of amplification often, (but not always), using vacuum tubes. Typically low power output, low damping factor and relatively high distortion. Single-ended enthusiasts claim that the sound quality is more "real".
Song tempo
Describes the speed at which the notes of a song are played. Largely dictated by the choice of musical style, tempo is indicated in BPM.
Sound generator
Device or software that produces sounds suitable for use in musical applications.
Sounds
Generic term that in this term describes the auditory effects produced by instruments.
Sound Pressure Level (Spl):
Given in decibels (DB) is an expression of loudness or volume. A 10db increase in SPL represents a doubling in volume. Live orchestral music reaches brief peaks in the 105db range and live rock easily goes over 120db.
Soundstage
A listening term the refers to the placement of a stereo image in a fashion that replicates the original performance. A realistic soundstage has proportional width, depth and height.
Sound Waves
Sound waves can be thought of like the waves in water. Frequency determines the length of the waves; amplitude or volume determines the height of the waves. At 20Hz, the wavelength is 56 feet long! These long waves give bass its penetrating ability, (why you can hear car boomers blocks away).
Speaker Level
Taken from the speaker terminals. This signal has already been amplified.
Spectral balance
Balance across the entire frequency spectrum of the audio range.
Standing wave
A buildup of sound level at a particular frequency that is dependent upon the dimensions of a resonant room, car interior, or enclosure. It occurs when the rate of energy loss equals the rate of energy input into the system. This is what you hear when you listen into a sea shell.
Stereo
From the Greek meaning solid. The purpose of stereo is not to give you separate right and left channels, but to provide the illusion of a three-dimensional, holographic image between the speakers.
Step sequencer
A device or software function that facilitates the process of coming up with melody lines or rhythmic phrases intuitively by experimentation.
Studio equipment
All the gear in a music studio. This includes mixers, effects and synthesizers and a bunch of other fun toys.
Studio environment
The entirety of all devices required for a musical production, for example, mixers, instruments and effects.
Subwoofer
A speaker designed exclusively for low-frequency reproduction. A true subwoofer should be able to at least reach into the bottom octave (20-40Hz). There are many "subwoofers" on the market that would be more accurately termed "woofers".
Surround (suspension)
The outer suspension of a speaker cone; holds the diaphragm in place but allows it to move when activated. Usually made of foam or rubber.
Surround Sound
Sound extracted from the stereo signal sent to smaller rear or side speakers used in a home theater.
Synthesizer
An electronic musical instrument that generates sounds unobtainable from ordinary musical instruments. It can be manipulated in variety of ways.
T
THX
Refers to a series of specifications for surround sound systems. Professional THX is used in commercial movie theaters. Home THX specifications are not published and manufacturers must sign non-disclosure waivers before submitting their products for THX certification. Manufacturers that receive certification for their products must pay a royalty on units sold.
Timbre
The quality of a sound that distinguishes it from other sounds of the same pitch and volume. The distinctive tone of an instrument or a singing voice.
Timbral
Refers to the overall frequency balance of a system. In a perfect world, all systems would have complete tonal neutrality. With current technology, this ideal is approached but not met. Listening to many equally "good" speakers will reveal that some sound warmer than others, some sound brighter etc... In a surround sound system it is important that all speakers have a close timbral match for the highest degree of sonic realism.
Toolbox
Menu containing editing tools for arranging and editing audio and MIDI editors.
Total harmonic distortion (THD)
Refers to a device adding harmonics that were not in the original signal. For example: a device that is fed a 20Hz sine wave that is also putting out 40Hz, 80Hz etc. Not usually a factor in most modern electronics, but still a significant design problem in loudspeakers.
Tracks
Tracks contain the individual musical elements and MIDI or audio data.
Transducer
A device that converts one form of energy to another. Playback transducers are the phono cartridge, which changes mechanical vibrations into electrical energy, and the loudspeakers, which change it back, from electrical energy coming from the amp to mechanical movement of the diaphragm, causing audible pressure changes in the air.
Transmission Line
Also referred to as a T-line. A type of bass cabinet in which the back wave follows a relatively long, usually damped path before being ported to the outside. T-lines are usually rather large and costly cabinets to manufacture. Opinions vary widely over the "best" type of bass cabinet, but much has to do with how well a given design, such as a transmission line is implemented.
Transient response
The ability of a component to respond quickly and accurately to transients. Transient response affects reproduction of the attack and decay characteristics of a sound.
Transparency
Listening term. An analog that can be best "pictured" in photography. The more "transparent" the sound, the clearer the auditory picture.
Transients
Instantaneous changes in dynamics, producing steep wave fronts.
Transport bar
Central control panel of a sequencer. Among other things, it lets you start record, play back and navigate through the arrangement.
Tuning Frequency
The helmholtz resonant frequency of a box. Also refers to the resonant frequency of other types of systems.
Tweeter
A speaker, (driver), used to reproduce the higher range of frequencies. To form a full-range system, a tweeter needs to be combined with a woofer, (2-way system), or a woofer and midrange, (3-way system).
Q-R
Q
Q or Quality Factor
Is a measure of damping. Modern home speaker systems have Q values ranging from <>
Quantize
An editing function of the sequencer. Out-of-time notes that don't fall into the desired rhythmic pattern are automatically shifted so they are in time.
R
RAM (Random Access Memory)
Term for the main memory of a computer.
RCA Connector
"Phono" plugs, used primarily as low-level connections between Phonographs/CD players/Tuners/Recievers/Amplifiers
Real time
In this context, real time means that an event - changes in pitch, sound or volume - is rendered as it occurs.
Recording Level
Volume setting of the recorded audio signal.
ReCycle
Software tool for adjusting the tempo of drum loops and other sampled phrases, distributed by Steinberg.
Red Book
Specification developed by Sony and Philips that sets forth the format of an audio CD.
Refrain (Chorus)
A musical phrase normally based on a single-note melody line. A key component of an arrangement, it is a song's central motif that ups its recognition factor.
Resonant frequency
Any system has a resonance at some particular frequency. At that frequency, even a slight amount of energy can cause the system to vibrate. A stretched piano string, when plucked, will vibrate for a while at a certain fundamental frequency. Plucked again, it will again vibrate at that same frequency. This is its natural or resonant frequency. While this is the basis of musical instruments, it is undesirable in music-reproducing instruments like audio equipment.
Ribbon Speaker
A type of speaker that uses a pleated conductor suspended between magnets. Most true ribbons are tweeters only. Sometimes confused with magnetic-planar speakers.
RMS (root-mean-square)
The square root of the mean of the sum of the squares. Commonly used as the effective value of measuring a sine wave's electrical power. A standard in amplifier measurements.
Roll-off (cut-off)
The attenuation that occurs at the lower or upper frequency range of a driver, network, or system. The roll-off frequency is usually defined as the frequency where response is reduced by -3 dB.
O-P
O
Octave
An octave is a doubling or halving of frequency. 20Hz-40Hz is often considered the bottom octave. Each octave you add on the bottom requires that your speakers move four times as much air!
Ohm
A unit of electrical resistance or impedance.
Ohm's Law
The basic law of electric circuits. It states that the current [I] in amperes in a circuit is equal to the voltage [E] in volts divided by the resistance [R] in ohms; thus, I = E/R.
OMS (Open Music System)
System expansion for Mac OS that allows MIDI devices and Apple computers to communicate.
Out of Phase
When speakers are mounted in reverse polarity, i.e... one speaker is wired +/+ and -/- from the amp and the other is wired +/- and -/+. Bass response will be very thin due to cancellation.
Output
The sound level produced by a loudspeaker.
Overload
A condition in which a system is given too high of an input level. A common cause of distortion or product failure.
Overtones
See Harmonics.
P
PCM
Pulse Code Modulation. A means of digital encoding.
Partitions
Subdivisions of the data area on a hard disk. Every partition has its own disk drive ID.
Parts
Individual sections of a MIDI or audio track.
Passive Radiator
A device that looks just like an ordinary driver, except it has no magnet or voice coil. A passive radiator is usually a highly compliant device, with a similar cone material and surround found on regular active drivers. The radiator must usually be at least as large (or larger) than the driver it is aligned with. The passive radiator is tuned to Fb and used in place of a port.
Patch editor
Software application that provides the means to process and exchange the instrument sounds of an audio card's MIDI sound generator.
PC Card (formerly PCMCIA)
Standardized slot designed to connect hardware accessories to mobile computers.
PCI bus (Peripheral Component Interface)
Slot in the PC or Mac (bus) designed to take internal expansion cards.
Phase Cancellation
Where two oscillating frequencies move in and out of phase with each other. Chorus effects attempt to emulate this behaviour. Imagine two people playing a guitar riff. It would be very rare indeed for them to play exactly in time with each other. Where they don't, phase cancellation occurs.
Phase Coherence
The relationship and timing of sounds that come from different drivers (subs, mids, tweets) mounted in different locations.
Phase Distortion
A type of audible distortion caused by time delay between various parts of the signal.
Planar Source
Most electrostatics and magnetic planars have a large surface area. Think of a wide board dropped flat onto the water surface. The sound can be extremely coherent, but the listening window is effectively limited to being directly on-axis of both the left and right planar speaker.
Plug-ins
Unable to run on their own, these software modules plug into a sequencer, adding new sound generators or effects to it.
Point-Source
Most multi-unit loudspeakers try to approximate a point-source. Think of a pebble dropped into the water and the expanding wave pattern away from impact. Obviously it is difficult to integrate multiple point-sources into a truly coherent expanding wave. The best designs do quite well with careful driver engineering and crossover development.
Polarity
A speaker, for example, has a positive and a negative input terminal. Connecting a battery directly to the speaker will result in the diaphragm moving outward. If you reverse the battery leads, the diaphragm will move inward.
Caution: Too high of a voltage battery will also burn out the speaker!
Ported Enclosure:
A type of speaker enclosure that uses a duct or port to improve efficiency at low frequencies.
Power (P)
The time rate of doing work or the rate at which energy is used. One equation for Power:
P = Volts^2 / Impedance
PowerBook
Product name for mobile Apple computers.
Processor
Highly complex arithmetic unit built into a chip - the brain of a computer, so to speak.
Push-Pull Configuration
One driver is mounted normally, the second is mounted so that it faces into the enclosure, both sharing the same internal volume and wired out of phase with one another. Although electrically out of phase with one another, the drivers are acoustically in phase since they move in the same direction. This alignment theoretically reduces second order harmonic distortion.
Push-pull
Most common type of amplification that amplifies the negative and positive sides of the waveform separately. Allows for much higher power output than single-ended.
Pre-amplifier
Or Pre-amp is a device that takes a source signal, such as from a turntable, tape-deck or CD player, and passes this signal on to a power-amplifier(s). The pre-amp may have a number of controls such as source selector switches, balance, volume and possibly tone-controls.
Octave
An octave is a doubling or halving of frequency. 20Hz-40Hz is often considered the bottom octave. Each octave you add on the bottom requires that your speakers move four times as much air!
Ohm
A unit of electrical resistance or impedance.
Ohm's Law
The basic law of electric circuits. It states that the current [I] in amperes in a circuit is equal to the voltage [E] in volts divided by the resistance [R] in ohms; thus, I = E/R.
OMS (Open Music System)
System expansion for Mac OS that allows MIDI devices and Apple computers to communicate.
Out of Phase
When speakers are mounted in reverse polarity, i.e... one speaker is wired +/+ and -/- from the amp and the other is wired +/- and -/+. Bass response will be very thin due to cancellation.
Output
The sound level produced by a loudspeaker.
Overload
A condition in which a system is given too high of an input level. A common cause of distortion or product failure.
Overtones
See Harmonics.
P
PCM
Pulse Code Modulation. A means of digital encoding.
Partitions
Subdivisions of the data area on a hard disk. Every partition has its own disk drive ID.
Parts
Individual sections of a MIDI or audio track.
Passive Radiator
A device that looks just like an ordinary driver, except it has no magnet or voice coil. A passive radiator is usually a highly compliant device, with a similar cone material and surround found on regular active drivers. The radiator must usually be at least as large (or larger) than the driver it is aligned with. The passive radiator is tuned to Fb and used in place of a port.
Patch editor
Software application that provides the means to process and exchange the instrument sounds of an audio card's MIDI sound generator.
PC Card (formerly PCMCIA)
Standardized slot designed to connect hardware accessories to mobile computers.
PCI bus (Peripheral Component Interface)
Slot in the PC or Mac (bus) designed to take internal expansion cards.
Phase Cancellation
Where two oscillating frequencies move in and out of phase with each other. Chorus effects attempt to emulate this behaviour. Imagine two people playing a guitar riff. It would be very rare indeed for them to play exactly in time with each other. Where they don't, phase cancellation occurs.
Phase Coherence
The relationship and timing of sounds that come from different drivers (subs, mids, tweets) mounted in different locations.
Phase Distortion
A type of audible distortion caused by time delay between various parts of the signal.
Planar Source
Most electrostatics and magnetic planars have a large surface area. Think of a wide board dropped flat onto the water surface. The sound can be extremely coherent, but the listening window is effectively limited to being directly on-axis of both the left and right planar speaker.
Plug-ins
Unable to run on their own, these software modules plug into a sequencer, adding new sound generators or effects to it.
Point-Source
Most multi-unit loudspeakers try to approximate a point-source. Think of a pebble dropped into the water and the expanding wave pattern away from impact. Obviously it is difficult to integrate multiple point-sources into a truly coherent expanding wave. The best designs do quite well with careful driver engineering and crossover development.
Polarity
A speaker, for example, has a positive and a negative input terminal. Connecting a battery directly to the speaker will result in the diaphragm moving outward. If you reverse the battery leads, the diaphragm will move inward.
Caution: Too high of a voltage battery will also burn out the speaker!
Ported Enclosure:
A type of speaker enclosure that uses a duct or port to improve efficiency at low frequencies.
Power (P)
The time rate of doing work or the rate at which energy is used. One equation for Power:
P = Volts^2 / Impedance
PowerBook
Product name for mobile Apple computers.
Processor
Highly complex arithmetic unit built into a chip - the brain of a computer, so to speak.
Push-Pull Configuration
One driver is mounted normally, the second is mounted so that it faces into the enclosure, both sharing the same internal volume and wired out of phase with one another. Although electrically out of phase with one another, the drivers are acoustically in phase since they move in the same direction. This alignment theoretically reduces second order harmonic distortion.
Push-pull
Most common type of amplification that amplifies the negative and positive sides of the waveform separately. Allows for much higher power output than single-ended.
Pre-amplifier
Or Pre-amp is a device that takes a source signal, such as from a turntable, tape-deck or CD player, and passes this signal on to a power-amplifier(s). The pre-amp may have a number of controls such as source selector switches, balance, volume and possibly tone-controls.
M-N
M
Magnetic-Planar Speakers
A type of speaker that uses a flat diaphragm with a voice coil etched or bonded to it to radiate sound. If the magnets are both in front of and behind the diaphragm, it becomes a push-pull magnetic-planar.
Mastering
A process by which a mixed-down piece of music is given a final sonic and electronic buff; the final step before the track is burned onto CD.
Maximum power rating
A meaningless specification.
Megacycle
A unit of measure for processor clock frequency. This is a benchmark specification that provides some insight into the computing speed and performance capability of a computer.
Melody line
Single-note, instantly recognizable motif that conjures up a specific musical atmosphere.
MIDI (Musical Instrument Digital Interface)
Created in 1982, this is the industry standard governing the transmission of control commands for electronic music instruments and studio devices.
MIDI adapter
A cable connector that turns the game-port of an audio card into a MIDI port.
MIDI event
A term used to describe an individual command or message sent via MIDI.
MIDI hardware
Any MIDI-compatible device.
MIDI instruments
Sound generators that can be played via MIDI.
MIDI interface
Accessory that connects MIDI devices to the computer.
MIDI keyboard
A keyboard used to play MIDI sound generators. It may or may not be equipped with an audio generator.
Midrange
A speaker, (driver), used to reproduce the middle range of frequencies. A midrange is combined with a woofer for low frequencies and a tweeter for high frequencies to form a complete, full-range system.
Mixer
A device that lets you voice or shape the signals of several audio sources and converge them into a single master audio signal.
Mixman
Software for the arrangement of music tracks on the basis of drum loops and other sampled phrases, distributed by Steinberg.
Monitoring environment
Combination of loudspeakers and amp by which audio signals are made audible.
Monopole
Any speaker that encloses the backwave of the speaker device even though part of this backwave may be released via a port or duct. The primary radiation at most frequencies will be from the driver front. If the driver is not enclosed it becomes a dipole.
MOSFET
Metal Oxide Semiconductor Field Effect Transistors. Used in most modern, quality car audio amplifiers in the power supply (and sometimes in the output stage). MOSFET's run cooler than normal bipolar transistors, and have a faster switching speed.
MP3 (MPEG 1 Layer 3)
A data reduction process for audio files developed by Fraunhofer Institute; it has become the established format for distributing music over the Internet.
Muddy
Listening term. A sound that is poorly defined, sloppy or vague. For example, a "muddy" bass is often boomy with all the notes tending to run together.
Muting
To greatly decrease the volume level. Many receivers and pre-amplifiers have a muting control which allows the volume level to be cut way down without changing the master volume control. Great for when the phone rings.
Multimedia software
Programs for playing back or processing static images, audio and video.
Multi-tracking
This describes a process in which several tracks are played back simultaneously, which allows a song to be recorded step by step rather than all at once.
Musician's portal
Website on which musicians can publish music and swap stories with other musicians.
Music production
The full sweep of musical activity involved in going from an idea to a finished song.
N
Noise
Any background noise, hissing, or interference caused by other computer components such as hard disks.
Non-destructive editing
Audio data on the hard disk remains in its original state, meaning that it is not physically changed during the editing.
Nonlinearity
What goes into a system comes out changed by its passage through that system-in other words, distorted. The ideal of an audio component and an audio system is to be linear, or nondistorting, with the image on one side of the mirror identical to the image on the other side.
Normalize
A process by which the volume of an audio file is boosted to peak level.
K-L
K
Kevlar
Material developed by Dupont that is has an exceptional strength to weight ratio. Used extensively in bullet-proof vests, skis, sailboat hulls, etc. In audio, used in many variations for speaker cones.
Kilohertz (kHz)
One thousand hertz.
L
Latency
This term describes the amount of time computers and audio hardware take to generate or process audio signals. It is the delay between the actual start of an event and the moment in which it becomes audible.
Linear frequency response
This means that the frequencies that make up an audio signal are rendered by audio hardware at levels that are directly proportionate to the input volume.
Line Level
CD players, VCRs, Laserdisc Players etc... are connected in a system at line level, usually with shielded RCA type interconnects. Line level is before power amplification. In a system with separate pre-amp and power-amp the pre-amp output is line level. Many surround sound decoders and receivers have line level outputs as well.
Line-Source
A speaker device that is long and tall. Imagine a narrow dowel dropped flat onto the water's surface. The line-source has very limited vertical dispersion, but excellent horizontal dispersion.
Lobing
Any time more than one speaker device covers the same part of the frequency range there will be some unevenness in the output. (Picture the waves from one pebble dropped into a calm pool vs. two pebbles dropped several inches apart.) Lobing means that the primary radiation pattern(s) is at some angle above or below the centerline between the two drivers. Good crossover design takes this into account.
Loudness
Another term for volume.
Low Frequency Extension
Manufacturers, writers and salespeople toss around all kinds of numbers and terminology that can be very confusing and misleading. "This $300 shoebox sized sub is flat to 20Hz". Right, in your dreams . . . How is that cheap, tiny box and driver going to reproduce a 56 foot wavelength with enough power to be heard?
It will not. Good bass reproduction requires moving a lot of air and playback at realistic volumes. Remember the rule of needing to move four times the air to go down one octave.
Example: You have a pair of good quality tower speakers with 10" woofers that produce good bass down to around 40Hz. The salesman is telling you that his little subwoofer with a single 10" woofer will extend your system down to 20Hz.
If you've been paying attention, you know that his woofer will have to move eight times as much air as each of your 10" woofers, not likely. Adding that subwoofer to your system might give you more apparent bass energy, and in fact may help a little with movie special effects, but it is unlikely to extend bass response significantly.
Low-Pass Filter
A circuit that allows low frequencies to pass but rolls off the high frequencies. Most subwoofers have low-pass filters built in and many surround sound decoders have subwoofer outputs that have been low-pass filtered.
Kevlar
Material developed by Dupont that is has an exceptional strength to weight ratio. Used extensively in bullet-proof vests, skis, sailboat hulls, etc. In audio, used in many variations for speaker cones.
Kilohertz (kHz)
One thousand hertz.
L
Latency
This term describes the amount of time computers and audio hardware take to generate or process audio signals. It is the delay between the actual start of an event and the moment in which it becomes audible.
Linear frequency response
This means that the frequencies that make up an audio signal are rendered by audio hardware at levels that are directly proportionate to the input volume.
Line Level
CD players, VCRs, Laserdisc Players etc... are connected in a system at line level, usually with shielded RCA type interconnects. Line level is before power amplification. In a system with separate pre-amp and power-amp the pre-amp output is line level. Many surround sound decoders and receivers have line level outputs as well.
Line-Source
A speaker device that is long and tall. Imagine a narrow dowel dropped flat onto the water's surface. The line-source has very limited vertical dispersion, but excellent horizontal dispersion.
Lobing
Any time more than one speaker device covers the same part of the frequency range there will be some unevenness in the output. (Picture the waves from one pebble dropped into a calm pool vs. two pebbles dropped several inches apart.) Lobing means that the primary radiation pattern(s) is at some angle above or below the centerline between the two drivers. Good crossover design takes this into account.
Loudness
Another term for volume.
Low Frequency Extension
Manufacturers, writers and salespeople toss around all kinds of numbers and terminology that can be very confusing and misleading. "This $300 shoebox sized sub is flat to 20Hz". Right, in your dreams . . . How is that cheap, tiny box and driver going to reproduce a 56 foot wavelength with enough power to be heard?
It will not. Good bass reproduction requires moving a lot of air and playback at realistic volumes. Remember the rule of needing to move four times the air to go down one octave.
Example: You have a pair of good quality tower speakers with 10" woofers that produce good bass down to around 40Hz. The salesman is telling you that his little subwoofer with a single 10" woofer will extend your system down to 20Hz.
If you've been paying attention, you know that his woofer will have to move eight times as much air as each of your 10" woofers, not likely. Adding that subwoofer to your system might give you more apparent bass energy, and in fact may help a little with movie special effects, but it is unlikely to extend bass response significantly.
Low-Pass Filter
A circuit that allows low frequencies to pass but rolls off the high frequencies. Most subwoofers have low-pass filters built in and many surround sound decoders have subwoofer outputs that have been low-pass filtered.
I-J
I
Imaging
Listening term. A good stereo system can provide a stereo image that has width, depth and height. The best imaging systems will define a nearly holographic re-creation of the original sound
Impedance
Impedance is a measure of electrical resistance specified in ohms. Speakers are commonly listed as 4 or 8 ohms but speakers are reactive devices and a nominal 8 ohm speaker might measure from below 4 ohms to 60 or more ohms over its frequency range. This varying impedance curve is different for each speaker model and makes it impossible to design a really effective "generic" speaker level high-pass filter. Active devices like amplifiers typically have an input impedance between about 10,000-100,000 ohms and the impedance is the same regardless of frequency.
Inductance (L)
The capability of a coil to store energy in a magnetic field surrounding it. It produces an impedance to an ac current. Inductors are commonly used in audio as low pass crossovers.
Infinite Baffle
A baffle that completely isolates the back wave of a driver from the front without a standard enclosure.
Infrasonic (Subsonic) Filter
A filter designed to remove extremely low frequency (25Hz or lower) noise from the audio signal. Useful for Ported box designs.
Interconnects
Cables that are used to connect components at a low signal level. Examples include CD player to receiver, pre-amplifier to amplifier, etc. Most interconnects use a shielded construction to prevent interference. Most audio interconnects use RCA connections although balanced interconnects use XLR connections.
Isobarik Enclosure
A trade name for a compound enclosure.
Insert effect
An effect that is inserted between an audio track and the mixer.
Intro
The beginning of an arrangement. It gradually introduces the song and slowly builds up musical tension.
J
Jitter
A tendency towards lack of synchronization caused by electrical changes. Technically the unexpected (and unwanted) phase shift of digital pulses over a transmission medium. A discrepancy between when a digital edge transition is supposed to occur and when it actually does occur - think of it as nervous digital, or maybe a digital analogy to wow and flutter.
Imaging
Listening term. A good stereo system can provide a stereo image that has width, depth and height. The best imaging systems will define a nearly holographic re-creation of the original sound
Impedance
Impedance is a measure of electrical resistance specified in ohms. Speakers are commonly listed as 4 or 8 ohms but speakers are reactive devices and a nominal 8 ohm speaker might measure from below 4 ohms to 60 or more ohms over its frequency range. This varying impedance curve is different for each speaker model and makes it impossible to design a really effective "generic" speaker level high-pass filter. Active devices like amplifiers typically have an input impedance between about 10,000-100,000 ohms and the impedance is the same regardless of frequency.
Inductance (L)
The capability of a coil to store energy in a magnetic field surrounding it. It produces an impedance to an ac current. Inductors are commonly used in audio as low pass crossovers.
Infinite Baffle
A baffle that completely isolates the back wave of a driver from the front without a standard enclosure.
Infrasonic (Subsonic) Filter
A filter designed to remove extremely low frequency (25Hz or lower) noise from the audio signal. Useful for Ported box designs.
Interconnects
Cables that are used to connect components at a low signal level. Examples include CD player to receiver, pre-amplifier to amplifier, etc. Most interconnects use a shielded construction to prevent interference. Most audio interconnects use RCA connections although balanced interconnects use XLR connections.
Isobarik Enclosure
A trade name for a compound enclosure.
Insert effect
An effect that is inserted between an audio track and the mixer.
Intro
The beginning of an arrangement. It gradually introduces the song and slowly builds up musical tension.
J
Jitter
A tendency towards lack of synchronization caused by electrical changes. Technically the unexpected (and unwanted) phase shift of digital pulses over a transmission medium. A discrepancy between when a digital edge transition is supposed to occur and when it actually does occur - think of it as nervous digital, or maybe a digital analogy to wow and flutter.
G-H
G
Gain
To increase in level. The function of a volume control.
Game-port
Found on many PC audio cards, it is a connector designed to take joysticks. With a MIDI adapter, it can be used as a simple MIDI interface.
H
Haas effect
The discovery of this effect is attributed to Halmut Haas in 1949.
If sounds arrive from several sources, the ears and brain will identify only the nearest. In other words, if our ears receive similar sounds coming from various sources, the brain will latch onto the sound that arrives first. If the time difference is up to 50 milliseconds, the early arrival sound can dominate the later arrival sound, even if the later arrival is as much as 10 dB louder.
Hard disk recording
Process by which audio data is loaded to hard disk.
Harmonics
Also called overtones, these are vibrations at frequencies that are multiples of the fundamental.
Harmonics extend without limit beyond the audible range. They are characterized as even-order and odd-order harmonics. A second-order harmonic is two times the frequency of the fundamental; a third order is three times the fundamental; a fourth order is four times the fundamental; and so forth.
Each even-order harmonic: second, fourth, sixth, etc... is one octave, or multiples of one octave, higher than the fundamental; these even-order overtones are therefore musically related to the fundamental.
Odd-order harmonics, on the other hand: third, fifth, seventh, and up-create a series of notes that are not related to any octave overtones and therefore may have an unpleasant sound. Audio systems that emphasize odd-order harmonics tend to have a harsh, hard quality.
HDCD
High-Definition Compact Disc.
A proprietary system by Pacific Microsonics that requires special encoding during the recording process. Some observers report HDCD discs as having better sound. To gain the benefits requires having special HDCD in your CD player.
Headroom
The ability of an amp to go beyond its rated power for short durations in order to reproduce musical peaks without distortion. This capability is often dependent on the power supply used in the design.
Head Unit
The in dash control center of a car audio system, usually consisting of an internal low powered amp, AM/FM receiver, and either a tape or CD player (or both).
Hearing Sensitivity
The human ear is less sensitive at low frequencies than in the midrange. Turn your volume knob down and notice how the bass seems to"disappear". To hear low bass requires an adequate SPL level. To hear 25Hz requires a much higher SPL level than to hear 250Hz. In the REAL world, low frequency sounds are reproduced by large objects; bass drums, string bass, concert grand pianos, etc. Listen to the exhaust rumble of a 454 cubic inch V8 engine vs. the whine of the little four banger. The growl of a lion vs. the meow of your favorite kitty. As frequency decreases we perceive more by feel than actual hearing and we lose our ability to hear exact pitch.
Hertz (Hz)
A unit of measurement denoting frequency, originally measured as: Cycles Per Second (CPS): 20 Hz = 20 CPS. Kilohertz (kHz) are hertz measured in multiples of 1,000.
High-end music studio
Studio environment that is equipped with exceptionally high-quality, exorbitantly expensive devices.
High-Pass Filter
A circuit that allows high frequencies to pass but rolls off the low frequencies. When adding a subwoofer it is often desirable to roll-off the low frequencies to the main amplifiers and speakers. This will allow the main speakers to play louder with less distortion. High-pass filters used at speaker level are usually not very effective unless properly designed for a specific main speaker (see impedance below).
Home Theater
An audio system designed to reproduce the theater sound experience while viewing film at home. Minimally consisting of a Dolby Pro Logic® surround sound receiver, left and right front speakers, a center channel speaker, and two surround speakers. These plus optional subwoofer(s), surround speaker(s), and digital formats such as Dolby Digital® can enhance the viewing experience by drastically improving the sound quality of movie soundtracks.
Gain
To increase in level. The function of a volume control.
Game-port
Found on many PC audio cards, it is a connector designed to take joysticks. With a MIDI adapter, it can be used as a simple MIDI interface.
H
Haas effect
The discovery of this effect is attributed to Halmut Haas in 1949.
If sounds arrive from several sources, the ears and brain will identify only the nearest. In other words, if our ears receive similar sounds coming from various sources, the brain will latch onto the sound that arrives first. If the time difference is up to 50 milliseconds, the early arrival sound can dominate the later arrival sound, even if the later arrival is as much as 10 dB louder.
Hard disk recording
Process by which audio data is loaded to hard disk.
Harmonics
Also called overtones, these are vibrations at frequencies that are multiples of the fundamental.
Harmonics extend without limit beyond the audible range. They are characterized as even-order and odd-order harmonics. A second-order harmonic is two times the frequency of the fundamental; a third order is three times the fundamental; a fourth order is four times the fundamental; and so forth.
Each even-order harmonic: second, fourth, sixth, etc... is one octave, or multiples of one octave, higher than the fundamental; these even-order overtones are therefore musically related to the fundamental.
Odd-order harmonics, on the other hand: third, fifth, seventh, and up-create a series of notes that are not related to any octave overtones and therefore may have an unpleasant sound. Audio systems that emphasize odd-order harmonics tend to have a harsh, hard quality.
HDCD
High-Definition Compact Disc.
A proprietary system by Pacific Microsonics that requires special encoding during the recording process. Some observers report HDCD discs as having better sound. To gain the benefits requires having special HDCD in your CD player.
Headroom
The ability of an amp to go beyond its rated power for short durations in order to reproduce musical peaks without distortion. This capability is often dependent on the power supply used in the design.
Head Unit
The in dash control center of a car audio system, usually consisting of an internal low powered amp, AM/FM receiver, and either a tape or CD player (or both).
Hearing Sensitivity
The human ear is less sensitive at low frequencies than in the midrange. Turn your volume knob down and notice how the bass seems to"disappear". To hear low bass requires an adequate SPL level. To hear 25Hz requires a much higher SPL level than to hear 250Hz. In the REAL world, low frequency sounds are reproduced by large objects; bass drums, string bass, concert grand pianos, etc. Listen to the exhaust rumble of a 454 cubic inch V8 engine vs. the whine of the little four banger. The growl of a lion vs. the meow of your favorite kitty. As frequency decreases we perceive more by feel than actual hearing and we lose our ability to hear exact pitch.
Hertz (Hz)
A unit of measurement denoting frequency, originally measured as: Cycles Per Second (CPS): 20 Hz = 20 CPS. Kilohertz (kHz) are hertz measured in multiples of 1,000.
High-end music studio
Studio environment that is equipped with exceptionally high-quality, exorbitantly expensive devices.
High-Pass Filter
A circuit that allows high frequencies to pass but rolls off the low frequencies. When adding a subwoofer it is often desirable to roll-off the low frequencies to the main amplifiers and speakers. This will allow the main speakers to play louder with less distortion. High-pass filters used at speaker level are usually not very effective unless properly designed for a specific main speaker (see impedance below).
Home Theater
An audio system designed to reproduce the theater sound experience while viewing film at home. Minimally consisting of a Dolby Pro Logic® surround sound receiver, left and right front speakers, a center channel speaker, and two surround speakers. These plus optional subwoofer(s), surround speaker(s), and digital formats such as Dolby Digital® can enhance the viewing experience by drastically improving the sound quality of movie soundtracks.
E-F
E
EBP
Efficiency Bandwidth Product.
A guide that helps a designer determine whether a driver is more suitable for a sealed or ported enclosure.
EBP of less than 50 indicates the driver should be used in a sealed enclosure. 50 - 90 indicates flexible design options... over 90 indicates best for a ported enclosure.
EBP = Fs / Qes
Editors
Processing windows in which MIDI and audio tracks are processed or edited in detail.
Effects
Devices or plug-ins that refine or reshape audio signals. Reverb, delay and chorus are typical effects that see widespread use.
Efficiency rating
The loudspeaker parameter that gives the level of sound output when measured at a prescribed distance with a standard level of electrical energy fed into the speaker.
Electronic Crossover
Uses active circuitry to send signals to appropriate drivers. More efficient than passive crossovers. Uses active circuitry to send signals to appropriate drivers. More efficient than passive crossovers.
Electrostatic Speaker
A speaker that radiates sound from a large diaphragm that is suspended between high-voltage grids.
Enhanced IDE (Integrated Device Electronics)
This standard serves to connect hard disks and other mass storage media to a computer.
Equalizer
Electronic set of filters used to boost or attenuate certain frequencies.
Extension
How extended a range of frequencies the device can reproduce accurately. Bass extension refers to how low a frequency tone will the system reproduce, high-frequency extension refers to how high in frequency will the system play.
F
Fc or Fcb
The system resonance frequency of a driver in a sealed box. The system resonance frequency of a driver in a sealed box.
Filter
An electrical circuit or mechanical device that removes or attenuates energy at certain frequencies.
Flat Response
The faithful reproduction of an audio signal; specifically, the variations in output level of less than 1 dB above or below a median level over the audio spectrum.
F3
The roll-off frequency at which the driver's response is down -3dB from the level of it's midband response.
Fletcher-Munson curve
Our sensitivity to sound depends on its frequency and volume. Human ears are most sensitive to sounds in the midrange. At lower volume levels humans are less sensitive to sounds away from the midrange, bass and treble sounds "seem" reduced in intensity at lower listening levels.
Free Air Resonance
The natural resonant frequency of a driver when operating outside an enclosure.
Frequency
The range of human hearing is commonly given as 20-20,000Hz (20Hz-20kHz). One hertz (Hz) represents one cycle per second, 20Hz represents 20 cycles per second and so on. Lower numbers are lower frequencies
Fs
The frequency of resonance for a driver in free air.
Full-range
A speaker designed to reproduce all or most of the sound spectrum.
Fundamental
The lowest frequency of a note in a complex wave form or chord.
EBP
Efficiency Bandwidth Product.
A guide that helps a designer determine whether a driver is more suitable for a sealed or ported enclosure.
EBP of less than 50 indicates the driver should be used in a sealed enclosure. 50 - 90 indicates flexible design options... over 90 indicates best for a ported enclosure.
EBP = Fs / Qes
Editors
Processing windows in which MIDI and audio tracks are processed or edited in detail.
Effects
Devices or plug-ins that refine or reshape audio signals. Reverb, delay and chorus are typical effects that see widespread use.
Efficiency rating
The loudspeaker parameter that gives the level of sound output when measured at a prescribed distance with a standard level of electrical energy fed into the speaker.
Electronic Crossover
Uses active circuitry to send signals to appropriate drivers. More efficient than passive crossovers. Uses active circuitry to send signals to appropriate drivers. More efficient than passive crossovers.
Electrostatic Speaker
A speaker that radiates sound from a large diaphragm that is suspended between high-voltage grids.
Enhanced IDE (Integrated Device Electronics)
This standard serves to connect hard disks and other mass storage media to a computer.
Equalizer
Electronic set of filters used to boost or attenuate certain frequencies.
Extension
How extended a range of frequencies the device can reproduce accurately. Bass extension refers to how low a frequency tone will the system reproduce, high-frequency extension refers to how high in frequency will the system play.
F
Fc or Fcb
The system resonance frequency of a driver in a sealed box. The system resonance frequency of a driver in a sealed box.
Filter
An electrical circuit or mechanical device that removes or attenuates energy at certain frequencies.
Flat Response
The faithful reproduction of an audio signal; specifically, the variations in output level of less than 1 dB above or below a median level over the audio spectrum.
F3
The roll-off frequency at which the driver's response is down -3dB from the level of it's midband response.
Fletcher-Munson curve
Our sensitivity to sound depends on its frequency and volume. Human ears are most sensitive to sounds in the midrange. At lower volume levels humans are less sensitive to sounds away from the midrange, bass and treble sounds "seem" reduced in intensity at lower listening levels.
Free Air Resonance
The natural resonant frequency of a driver when operating outside an enclosure.
Frequency
The range of human hearing is commonly given as 20-20,000Hz (20Hz-20kHz). One hertz (Hz) represents one cycle per second, 20Hz represents 20 cycles per second and so on. Lower numbers are lower frequencies
Fs
The frequency of resonance for a driver in free air.
Full-range
A speaker designed to reproduce all or most of the sound spectrum.
Fundamental
The lowest frequency of a note in a complex wave form or chord.
Thursday, November 1, 2007
C-D
C
Cabin gain
The low frequency boost normally obtained inside a vehicle interior when subs are properly mounted.
Capacitor
A device made up of two metallic plates separated by a dielectric (insulating material). Used to store electrical energy in the electrostatic field between the plates. It produces an impedance to an AC current (Alternating Current).
CENTRE Channel (or center (US))
In home theater, sound decoded from the stereo signal sent to a speaker mounted in front of the listener, specially designed to enhance voices and sound effects from a movie soundtrack. Used in car audio to help offset skewed stereo imaging due to seating positions in the automotive environment.
Channel Balance
In a stereo system, the level balance between left and right channels. Properly balanced, the image should be centered between the left-right speakers. In a home-theater system, refers to achieving correct balance between all the channels of the system.
Chorus (Refrain)
A musical phrase normally based on a single-note melody line. A key component of an arrangement, it is a song's central motif that ups its recognition factor.
Clipping
Refers to a type of distortion that occurs when an amplifier is driven into an overload condition. Usually the "clipped" waveform contains an excess of high-frequency energy. The sound becomes hard and edgy. Hard clipping is the most frequent cause of "burned out" tweeters. Even a low-powered amplifier or receiver driven into clipping can damage tweeters which would otherwise last virtually forever.
Class A, Class A-B etc...
In a sense, amplifying the audio signal means using the wall-current (usually either 120 or 240 volts) to increase the amplitude of the audio signal from mill-watts to watts. Different classes of amplifiers accomplish this in different ways. Turning a vacuum tube "on" or "off" with current demand increases the efficiency of the amplifier but may add switching distortion. A Class A amplifier is relatively inefficient, converting much energy to heat, but has no switching distortion.
Cms
Mechanical suspension compliance of a driver, consisting of the spider and surround.
Co-axial
A speaker type that utilizes a tweeter mounted at the center of a woofer cone. The idea being to have the sound source through the full frequency range become "coincident".
Coaxial Driver
- a speaker composed of two individual voice coils and cones; used for reproduction of sounds in two segments of the sound spectrum. See also triaxial driver.
Coherence
Listening term. Refers to how well integrated the sound of the system is.
Coloration
Listening term. A visual analog. A "colored" sound characteristic adds something not in the original sound. The coloration may be euphonically pleasant, but it is not as accurate as the original signal.
Compliance
The relative stiffness of a speaker suspension, specified as Vas.
Compression
In audio, compression means to reduce the dynamic range of a signal. Compression may be intentional or one of the effects of a system that is driven to overload.
Crossover
A frequency divider. Crossovers are used in speakers to route the various frequency ranges to the appropriate drivers. Additionally, many crossovers contain various filters to stabilize the impedance load of the speaker and or shape the frequency response. Some crossovers contain levels controls to attenuate various parts of the signal.
A passive crossover uses capacitors, coils and resistors, usually at speaker level. A passive crossover is load dependent (the transition may not be very smooth or accurate if a different speaker is substituted for the one the crossover was designed for).
An active crossover is based on integrated circuits (ICs), discreet transistors or tubes. An active crossover is impedance buffered and gives a consistent and accurate transition regardless of load.
Crossover Slope
High and low pass filters used for speakers do not cut-off frequencies like brick walls. The rolloff occurs over a number of octaves. Common filter slopes for speakers are 1st through 4th order corresponding to 6db/oct to 24db/oct. For example, a 1st. order, 6db/oct high pass filter at 100hz will pass 6db less energy at 50Hz and 12db less energy at 25Hz. Within the common 1st through 4th filters there is an endless variety of types including Butterworth, Linkwitz-Riley, Bessel, Chebychev, etc. Salesmen and product literature will sometimes make claims of clear superiority for the filter used in the product they are trying to sell. Since the subject fills books, suffice it to say that there is no one best filter, it depends on application and intended outcome. Good designers use the filters required to get the optimum performance from the system.
Cross-talk
Unwanted breakthrough of one channel into another. Also refers to the distortion that occurs when some signal from a music source that you are not listening to leaks into the circuit of the source that you are listening to.
Cutting
The process of removing unnecessary or undesirable sections of an audio or MIDI recording.
D
DAC
A Digital to Audio Converter. Converts a digital bitstream to an analog signal. Can be a separate "box" that connects between a CD Transport or CD Player and a pre-amplifier.
Damping (Damping factor)
Refers to the ability of an audio component to "stop" after the signal ends. For example, if a drum is struck with a mallet, the sound will reach a peak level and then decay in a certain amount of time to no sound. An audio component that allows the decay to drag on too long has poor damping, and less definition than it should. An audio component that is overdamped does not allow the initial energy to reach the full peak and cuts the decay short. "Boomy" or "muddy" sound is often the result of underdamped systems. "Dry" or "lifeless" sound may be the result of an overdamped system.
D'Appolito
Joe D'Appolito is credited with popularizing the MTM (Midrange-Tweeter-Midrange) type of speaker.
Decibel (dB)
Named after Alexander Graham Bell. We perceive differences in volume level in a logarithmic manner. Our ears become less sensitive to sound as its intensity increases. Decibels are a logarithmic scale of relative loudness. A difference of approx. 1 dB is the minimum perceptible change in volume, 3 dB is a moderate change in volume, and about 10 dB is an apparent doubling of volume:
· 0 dB is the threshold of hearing, 130 dB is the threshold of pain.
· Whisper: 15-25 dB
· Quiet background: about 35 dB
· Normal home or office background: 40-60 dB
· Normal speaking voice: 65-70 dB
· Orchestral climax: 105 dB
· Live Rock music: 120 dB+
· Jet aircraft: 140-180 dB
Defragmentation
A process by which data on a hard disk is rearranged in an order that enhances performance. Special defragmenting utilities are available for Windows and Mac OS.
Diaphragm
The part of a dynamic loudspeaker attached to the voice coil that moves and produces the sound. It usually has the shape of a cone or dome.
Diffraction
A change in the direction of a wave front that is caused by the wave moving past an obstacle.
Dipole
An open-back speaker that radiates sound equally front and rear. The front and rear waves are out of phase and cancellation will occur when the wavelengths are long enough to "wrap around". The answer is a large, wide baffle or to enclose the driver creating a monopole.
Direct Current (DC)
Current that moves in only one direction.
Dispersion
The spreading of sound waves as they leave a source. The spreading of sound waves as they leave a source.
Distortion
Anything that alters the musical signal. There are many forms of distortion, some of which are more audible than others. Distortion specs are often given for electronic equipment which are quite meaningless. As in all specifications, unless you have a thorough understanding of the whole situation, you will not be able to make conclusions about the sonic consequences.
DIY
Abbreviation for Do- It-Yourself. In audio, the most common DIY is building speakers but some hobbyists build everything from pre-amps to amplifiers to DACs.
Dolby Digital
Five-channel system consisting of left, center, right and left rear, right rear channels. All processing is done in the digital domain.
Unlike Dolby Prologic in which the rear effects channels are frequency limited to approx. 100-7000Hz, Dolby Digital rear channels are specified to contain the full 20-20Khz frequency content.
The AC3 standard also has a separate subwoofer channel for the lowest frequencies.
Dolby Digital EX Surround
Also referred to as Dolby Digital 6.1, adds a rear, center channel to the existing left, center, right and rear speakers. This format requires a 6.1 processor or receiver and DVDs that are 6.1 encoded.
Dolby Prologic
Four-channel system consisting of left, center, right and rear channel, (the single rear channel is usually played through two speakers).
Dome Tweeter
A high frequency speaker with a dome-shaped diaphragm.A high frequency speaker with a dome-shaped diaphragm.
Double (Dual) Voice Coil (DVC)
A voice coil with two windings, generally used in woofers. Each voice coil can be connected to a stereo channel, or both voice coils can be wired in parallel or series to a single channel.
DTS
Digital Theater System. A multi-channel encoding/decoding system. Used in some movie theaters. Also now included in some home-theater processors. A competitor to Dolby Digital.
DSP
Digital Signal Processing. DSP can be used to create equalization, compression, etc. of a digital signal.
DVD
Digital Video Disc or Digital Versatile Disc. A relatively new standard that seeks to combine better-than-laser-disc quality video with better-than-CD quality audio in a disc the size of a CD. Requires special players. Seems to be a viable candidate to replace both Laser Discs and CDs, but the jury is still out.
Dynamic Headroom
The ability of an audio device to respond to musical peaks. For example, an amplifier may only be capable of a sustained 100 watts, but may be able to achieve peaks of 200 watts for the fraction of a second required for an intense, quick sound. In this example the dynamic headroom would equal 3 db.
Dynamic range
The range between the loudest and the softest sounds that are in a piece of music, or that can be reproduced by a piece of audio equipment without distortion (a ratio expressed in decibels). In speech, the range rarely exceeds 40 dB; in music, it is greatest in orchestral works, where the range may be as much as 75 dB.
Cabin gain
The low frequency boost normally obtained inside a vehicle interior when subs are properly mounted.
Capacitor
A device made up of two metallic plates separated by a dielectric (insulating material). Used to store electrical energy in the electrostatic field between the plates. It produces an impedance to an AC current (Alternating Current).
CENTRE Channel (or center (US))
In home theater, sound decoded from the stereo signal sent to a speaker mounted in front of the listener, specially designed to enhance voices and sound effects from a movie soundtrack. Used in car audio to help offset skewed stereo imaging due to seating positions in the automotive environment.
Channel Balance
In a stereo system, the level balance between left and right channels. Properly balanced, the image should be centered between the left-right speakers. In a home-theater system, refers to achieving correct balance between all the channels of the system.
Chorus (Refrain)
A musical phrase normally based on a single-note melody line. A key component of an arrangement, it is a song's central motif that ups its recognition factor.
Clipping
Refers to a type of distortion that occurs when an amplifier is driven into an overload condition. Usually the "clipped" waveform contains an excess of high-frequency energy. The sound becomes hard and edgy. Hard clipping is the most frequent cause of "burned out" tweeters. Even a low-powered amplifier or receiver driven into clipping can damage tweeters which would otherwise last virtually forever.
Class A, Class A-B etc...
In a sense, amplifying the audio signal means using the wall-current (usually either 120 or 240 volts) to increase the amplitude of the audio signal from mill-watts to watts. Different classes of amplifiers accomplish this in different ways. Turning a vacuum tube "on" or "off" with current demand increases the efficiency of the amplifier but may add switching distortion. A Class A amplifier is relatively inefficient, converting much energy to heat, but has no switching distortion.
Cms
Mechanical suspension compliance of a driver, consisting of the spider and surround.
Co-axial
A speaker type that utilizes a tweeter mounted at the center of a woofer cone. The idea being to have the sound source through the full frequency range become "coincident".
Coaxial Driver
- a speaker composed of two individual voice coils and cones; used for reproduction of sounds in two segments of the sound spectrum. See also triaxial driver.
Coherence
Listening term. Refers to how well integrated the sound of the system is.
Coloration
Listening term. A visual analog. A "colored" sound characteristic adds something not in the original sound. The coloration may be euphonically pleasant, but it is not as accurate as the original signal.
Compliance
The relative stiffness of a speaker suspension, specified as Vas.
Compression
In audio, compression means to reduce the dynamic range of a signal. Compression may be intentional or one of the effects of a system that is driven to overload.
Crossover
A frequency divider. Crossovers are used in speakers to route the various frequency ranges to the appropriate drivers. Additionally, many crossovers contain various filters to stabilize the impedance load of the speaker and or shape the frequency response. Some crossovers contain levels controls to attenuate various parts of the signal.
A passive crossover uses capacitors, coils and resistors, usually at speaker level. A passive crossover is load dependent (the transition may not be very smooth or accurate if a different speaker is substituted for the one the crossover was designed for).
An active crossover is based on integrated circuits (ICs), discreet transistors or tubes. An active crossover is impedance buffered and gives a consistent and accurate transition regardless of load.
Crossover Slope
High and low pass filters used for speakers do not cut-off frequencies like brick walls. The rolloff occurs over a number of octaves. Common filter slopes for speakers are 1st through 4th order corresponding to 6db/oct to 24db/oct. For example, a 1st. order, 6db/oct high pass filter at 100hz will pass 6db less energy at 50Hz and 12db less energy at 25Hz. Within the common 1st through 4th filters there is an endless variety of types including Butterworth, Linkwitz-Riley, Bessel, Chebychev, etc. Salesmen and product literature will sometimes make claims of clear superiority for the filter used in the product they are trying to sell. Since the subject fills books, suffice it to say that there is no one best filter, it depends on application and intended outcome. Good designers use the filters required to get the optimum performance from the system.
Cross-talk
Unwanted breakthrough of one channel into another. Also refers to the distortion that occurs when some signal from a music source that you are not listening to leaks into the circuit of the source that you are listening to.
Cutting
The process of removing unnecessary or undesirable sections of an audio or MIDI recording.
D
DAC
A Digital to Audio Converter. Converts a digital bitstream to an analog signal. Can be a separate "box" that connects between a CD Transport or CD Player and a pre-amplifier.
Damping (Damping factor)
Refers to the ability of an audio component to "stop" after the signal ends. For example, if a drum is struck with a mallet, the sound will reach a peak level and then decay in a certain amount of time to no sound. An audio component that allows the decay to drag on too long has poor damping, and less definition than it should. An audio component that is overdamped does not allow the initial energy to reach the full peak and cuts the decay short. "Boomy" or "muddy" sound is often the result of underdamped systems. "Dry" or "lifeless" sound may be the result of an overdamped system.
D'Appolito
Joe D'Appolito is credited with popularizing the MTM (Midrange-Tweeter-Midrange) type of speaker.
Decibel (dB)
Named after Alexander Graham Bell. We perceive differences in volume level in a logarithmic manner. Our ears become less sensitive to sound as its intensity increases. Decibels are a logarithmic scale of relative loudness. A difference of approx. 1 dB is the minimum perceptible change in volume, 3 dB is a moderate change in volume, and about 10 dB is an apparent doubling of volume:
· 0 dB is the threshold of hearing, 130 dB is the threshold of pain.
· Whisper: 15-25 dB
· Quiet background: about 35 dB
· Normal home or office background: 40-60 dB
· Normal speaking voice: 65-70 dB
· Orchestral climax: 105 dB
· Live Rock music: 120 dB+
· Jet aircraft: 140-180 dB
Defragmentation
A process by which data on a hard disk is rearranged in an order that enhances performance. Special defragmenting utilities are available for Windows and Mac OS.
Diaphragm
The part of a dynamic loudspeaker attached to the voice coil that moves and produces the sound. It usually has the shape of a cone or dome.
Diffraction
A change in the direction of a wave front that is caused by the wave moving past an obstacle.
Dipole
An open-back speaker that radiates sound equally front and rear. The front and rear waves are out of phase and cancellation will occur when the wavelengths are long enough to "wrap around". The answer is a large, wide baffle or to enclose the driver creating a monopole.
Direct Current (DC)
Current that moves in only one direction.
Dispersion
The spreading of sound waves as they leave a source. The spreading of sound waves as they leave a source.
Distortion
Anything that alters the musical signal. There are many forms of distortion, some of which are more audible than others. Distortion specs are often given for electronic equipment which are quite meaningless. As in all specifications, unless you have a thorough understanding of the whole situation, you will not be able to make conclusions about the sonic consequences.
DIY
Abbreviation for Do- It-Yourself. In audio, the most common DIY is building speakers but some hobbyists build everything from pre-amps to amplifiers to DACs.
Dolby Digital
Five-channel system consisting of left, center, right and left rear, right rear channels. All processing is done in the digital domain.
Unlike Dolby Prologic in which the rear effects channels are frequency limited to approx. 100-7000Hz, Dolby Digital rear channels are specified to contain the full 20-20Khz frequency content.
The AC3 standard also has a separate subwoofer channel for the lowest frequencies.
Dolby Digital EX Surround
Also referred to as Dolby Digital 6.1, adds a rear, center channel to the existing left, center, right and rear speakers. This format requires a 6.1 processor or receiver and DVDs that are 6.1 encoded.
Dolby Prologic
Four-channel system consisting of left, center, right and rear channel, (the single rear channel is usually played through two speakers).
Dome Tweeter
A high frequency speaker with a dome-shaped diaphragm.A high frequency speaker with a dome-shaped diaphragm.
Double (Dual) Voice Coil (DVC)
A voice coil with two windings, generally used in woofers. Each voice coil can be connected to a stereo channel, or both voice coils can be wired in parallel or series to a single channel.
DTS
Digital Theater System. A multi-channel encoding/decoding system. Used in some movie theaters. Also now included in some home-theater processors. A competitor to Dolby Digital.
DSP
Digital Signal Processing. DSP can be used to create equalization, compression, etc. of a digital signal.
DVD
Digital Video Disc or Digital Versatile Disc. A relatively new standard that seeks to combine better-than-laser-disc quality video with better-than-CD quality audio in a disc the size of a CD. Requires special players. Seems to be a viable candidate to replace both Laser Discs and CDs, but the jury is still out.
Dynamic Headroom
The ability of an audio device to respond to musical peaks. For example, an amplifier may only be capable of a sustained 100 watts, but may be able to achieve peaks of 200 watts for the fraction of a second required for an intense, quick sound. In this example the dynamic headroom would equal 3 db.
Dynamic range
The range between the loudest and the softest sounds that are in a piece of music, or that can be reproduced by a piece of audio equipment without distortion (a ratio expressed in decibels). In speech, the range rarely exceeds 40 dB; in music, it is greatest in orchestral works, where the range may be as much as 75 dB.
A-B
A
A-B Test
A test between two components. For example, a test between two different pre-amplifiers, or, when mixing, a test between a song with EQ tweaks, against the same song without.
For the test to be scientifically valid the levels should be matched.
ABX Comparator
A device that randomly selects between two components being tested. The listener doesn't know which device is being listened to.
AC3
See Dolby Digital
Acoustic suspension
A sealed or closed box speaker enclosure.
AES/EBU
Balanced digital connection. For example, used to connect a CD transport to a DAC. The AES/EBU standard uses XLR type connectors.
Alignment
A class of enclosure parameters that provides optimum performance for a woofer with a given value of Q.
Alpha
Term used in sealed enclosure designs to mean the ratio of Vas to Vb, where Vb is the volume of the box you will build.
Alternating Current (AC)
An electrical current that periodically changes in magnitude and direction.
Ambience
The acoustic characteristics of a space with regard to reverberation. A room with a lot of reverb is said to be "live"; one without much reverb is "dead."
Ampere (A)
The unit of measurement for electrical current in coulombs per second. There is one ampere in a circuit that has one ohm resistance when one volt is applied to the circuit. See Ohms Law.
Amplifier (Amp)
A device which increases signal level. Many types of amplifiers are used in audio systems. Amplifiers typically increase voltage, current or both.
Amplifier classes
Audio power amplifiers are classified primarily by the design of the output stage. Classification is based on the amount of time the output devices operate during each cycle of signal swing. Also defined in terms of output bias current, (the amount of current flowing in the output devices with no signal).
· Class A: Operation is where both devices conduct continuously for the entire cycle of signal swing, or the bias current flows in the output devices at all times. The key ingredient of class A operation is that both devices are always on. There is no condition where one or the other is turned off. Because of this, class A amplifiers are single-ended designs with only one type polarity output devices. Class A is the most inefficient of all power amplifier designs, averaging only around 20%. Because of this, class A amplifiers are large, heavy and run very hot. All this is due to the amplifier constantly operating at full power.The positive effect of all this is that class A designs are inherently the most linear, with the least amount of distortion.
· Class B: Operation is the opposite of class A. Both output devices are never allowed to be on at the same time, or the bias is set so that current flow in a specific output device is zero when not stimulated with an input signal, i.e., the current in a specific output flows for one half cycle. Thus each output device is on for exactly one half of a complete sinusoidal signal cycle. Due to this operation, class B designs show high efficiency but poor linearity around the crossover region. This is due to the time it takes to turn one device off and the other device on, which translates into extreme crossover distortion. Thus restricting class B designs to power consumption critical applications, e.g., battery operated equipment, such as 2-way radio and other communications audio.
· Class AB: Operation allows both devices to be on at the same time (like in class A), but just barely. The output bias is set so that current flows in a specific output device appreciably more than a half cycle but less than the entire cycle. That is, only a small amount of current is allowed to flow through both devices, unlike the complete load current of class A designs, but enough to keep each device operating so they respond instantly to input voltage demands. Thus the inherent non-linearity of class B designs is eliminated, without the gross inefficiencies of the class A design. It is this combination of good efficiency (around 50%) with excellent linearity that makes class AB the most popular audio amplifier design.
· Class AB plus B: Design involves two pairs of output devices: one pair operates class AB while the other (slave) pair operates class B.
· Class D: Operation is switching, hence the term switching power amplifier. Here the output devices are rapidly switched on and off at least twice for each cycle. Since the output devices are either completely on or completely off they do not theoretically dissipate any power. Consequently class D operation is theoretically 100% efficient, but this requires zero on-impedance switches with infinitely fast switching times -- a product we're still waiting for; meanwhile designs do exist with true efficiencies approaching 90%.
· Class G: Operation involves changing the power supply voltage from a lower level to a higher level when larger output swings are required. There have been several ways to do this. The simplest involves a single class AB output stage that is connected to two power supply rails by a diode, or a transistor switch. The design is such that for most musical program material, the output stage is connected to the lower supply voltage, and automatically switches to the higher rails for large signal peaks. Another approach uses two class AB output stages, each connected to a different power supply voltage, with the magnitude of the input signal determining the signal path. Using two power supplies improves efficiency enough to allow significantly more power for a given size and weight. Class G is becoming common for pro audio designs.
· Class H: Operation takes the class G design one step further and actually modulates the higher power supply voltage by the input signal. This allows the power supply to track the audio input and provide just enough voltage for optimum operation of the output devices. The efficiency of class H is comparable to class G designs.
Attenuate
To reduce in level.
Analogue
Before digital, the way all sound was reproduced. A smooth wavecycle rather than the digital 1's and 0's.
Aperiodic
Refers to a type of bass-cabinet loading. An aperiodic enclosure type usually features a very restrictive, (damped), port. The purpose of this restrictive port is not to extend bass response, but lower the Q of the system and reduce the impedance peak at resonance. Most restrictive ports are heavily stuffed with fiberglass, dacron or foam.
Audiophile
A person interested in sound reproduction.
AWS
Adaptive Woofer System, trademark of ACI. An active woofer system with built in user adjustable equalization capabilities.
B
Baffle
A surface used to mount a loudspeaker.
Referring to wiring: Audio signals require two wires. In an unbalanced line the shield is one of those wires. In a balanced line, there are two wires plus the shield. For the system to be balanced requires balanced electronics and usually employs XLR connectors. Balanced lines are less apt to pick up external noise. This is usually not a factor in home audio, but is a factor in professional audio requiring hundreds or even thousands of feet of cabling. Many higher quality home audio cables terminated with RCA jacks are balanced designs using two conductors and a shield instead of one conductor plus shield.
Bandwidth
The total frequency range of any system. Usually specified as something like: 20-20,000Hz plus or minus 3 db.
Band-pass Enclosure
A multi-chambered ported system.
Band-pass filter
An electric circuit designed to pass only middle frequencies.
Bass Blockers
Commercial name for auto-sound first order high pass crossovers (non-polarized capacitors), generally used on midbass or dash speakers to keep them from trying to reproduce deep bass.
Bass Reflex
A type of loudspeaker that uses a port or duct to augment the low-frequency response. Opinions vary widely over the "best" type of bass cabinet, but much has to do with how well a given design, such as a bass reflex is implemented.
Beaming
A tendency of a loudspeaker to concentrate the sound in a narrow path instead of spreading it.
Bessel crossover
A type of crossover design characterized by having a linear or maximally flat phase response. Linear phase response results in constant time-delay (all frequencies within the passband are delayed the same amount). Consequently the value of linear phase is it reproduces a near-perfect step response with no overshoot or ringing. The downside of the Bessel is a slow roll-off rate. The same circuit complexity in a Butterworth response rolls off much faster.
Bi-amplify
The use of two amplifiers, one for the lows, one for the highs in a speaker system. Could be built into the speaker design or accomplished with the use of external amplifiers and electronic crossovers.
Bi-wiring
The use of two pairs of speaker wire from the same amplifier to separate bass and treble inputs on the speaker.
BNC
A type of connection often used in instrumentation and sometimes in digital audio. BNC connectors sometimes are used for digital connections such as from a CD Transport to the input of a DAC.
Boomy
Listening term, refers to an excessive bass response that has a peak(s) in it.
Bright
Listening term. Usually refers to too much upper frequency energy.
Bridging
Combining both left and right stereo channels on an automotive amplifier into one higher powered mono channel. When an amplifier is bridged, the impedance that the amplifier actually "sees" is calculated based upon the output of both stereo channels. Here is a simple formula to help define this:
Bridged Mono Impedance = (Y / X)/2
Y = impedance of driver(s) (both drivers should be identical)
X = # of drivers in circuit
One 4 ohm sub in bridged mono is equal to hooking up two 2 ohm subs in stereo, one to each channel.
Butterworth crossover
A type of crossover circuit design having a maximally flat magnitude response, i.e., no amplitude ripple in the passband. This circuit is based upon Butterworth functions, also know as Butterworth polynomials.
Preface
Welcome to my site,
Dear all audio lover.
All the glossaries are adopted from many sources in the internet. You are very welcome to add the glossaries. Enjoy it.
Best Regards
Puj
Dear all audio lover.
All the glossaries are adopted from many sources in the internet. You are very welcome to add the glossaries. Enjoy it.
Best Regards
Puj
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