Computer music, indeed most computer stuff these days, attracts it's share of abbreviations and acronyms... so many in fact that, as much as I've tried to make TheWhippinpost accessible to all users - including speech-enabled browsers - this area is the most time-consuming to code.

Therefore, these glossary pages are the best place for "decrypting" some of the music terminology used on this site.

Music glossary pages:

Digital Audio Glossary: S-Z


Sampling CD

Jump to:

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.


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.


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.


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.


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.


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. 


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.


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.


An electronic musical instrument that generates sounds unobtainable from ordinary musical instruments. It can be manipulated in variety of ways.



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.


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.


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.


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 contain the individual musical elements and MIDI or audio data.


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.


Listening term. An analog that can be best "pictured" in photography. The more "transparent" the sound, the clearer the auditory picture.


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.


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).


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.



The total box volume, usually in cubic feet or liters. Used specifically in sealed and ported designs. 


The front volume of a bandpass design.


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.


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.


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.



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.


A speaker, (driver), used for low-frequency reproduction.  Usually larger and heavier than a midrange or tweeter.



A type of connector used for balanced lines. Used for microphones, balanced audio components and the AES/EBU digital connection.