wall wart. An external power supply consisting of a small box containing a transformer and other components that plugs directly into a wall outlet and then connects to the device it is powering with a thin cable. Wall warts are popular with manufacturers because they are inexpensive and easy to manufacture, and they move the potentially noisy transformer out of the device they are powering. Wall warts also simplify obtaining UL approval for a device. Consumers sometimes have less positive feelings; wall warts can take up more than one space on an outlet strip, are sometimes less than durable, and can fall out of a wall outlet easily. See also lump in the line.

warmth. One of those subjective terms that engineers and musicians use for describing audio. “Warmth” is usually defined as a smooth, rich sound quality, without harshness or over-brightness.

waterfall key (a.k.a. square front key). A type of key, often found on B3 organ-style instruments, that doesn’t have a lip or overhanging edge. Waterfall keys make it more comfortable for the player to do a “wipe” or gliss with the palm of his hand.

watermark. An identifying mark or code embedded in the data of a document or file. Ideally, a watermark should not be obvious and should not affect the original file. Watermarks are intended to help authors and content creators control distribution of their works.

watt. The unit for power. One watt equals one amp of current flowing through one volt. It was named for James Watt, a Scottish inventor and mechanical engineer who made major improvements to the steam engine, helping to open the door for the Industrial Revolution.

WAV file. A computer audio file format developed by Microsoft for Windows applications, though WAV files are now supported by most Macintosh audio applications as well. WAV files use the .wav file suffix. See also Broadcast WAV file.

wave file. See WAV file.

waveform. 1. Technically, a graph of the voltage of a periodic signal plotted versus time. 2. The “shape” of a sound wave; the waveform defines the timbre of a sound.

waveguide. A part of a monitor speaker cabinet designed to physically direct or guide the sound waves that are emerging from a driver, usually a tweeter.

wavelength. 1. Technically, the distance between one peak of a repeating or cyclical sound wave and the next peak. 2. The result of dividing the speed of sound by the frequency of a repeating or cyclical sound wave. 3. The physical length of a sound wave. Wavelength is important in calculating the modes of a room. See Table W.1.

wave scanning. A synthesis technique developed by Native Instruments that uses parallel oscillators that function almost like sequencers drawing from a wave table and fading between waves.

wave sequencing. A function of some oscillators that can crossfade between waveforms while a note is being held.

wavetable. A lookup table containing the parameters and data necessary for a synthesizer to create waveforms. Although the waveforms in a wavetable begin life as samples, in the wavetable itself the sample is “stored” as the instructions necessary to create the waveform using additive synthesis.

wavetable synthesis. A digital synthesizer that creates waveforms using additive synthesis techniques based on the data contained in a stored lookup table. Most wavetable synths are able to crossfade between waveforms while notes are playing to create complex raw sounds that are then processed using filters, envelopes, and other synthesis techniques.

WDM. Windows Driver Module. A Microsoft-developed driver protocol for the Windows OS platform. The WDM protocol was designed to take advantage of operating system code, DMA, and plug and play to allow greater efficiency.

weighted action. A type of keyboard action that uses weighted keys to simulate the feel of a grand piano.

weighting. When measuring audio, weighting modifies the results to (hopefully) match up better with how our ears hear. An example of weighting might be a curve applied to sound-pressure level measurements to more accurately reflect how our ears perceive loudness. Another weighting might compensate for the frequency response of our ear.

wet. A signal with processing, usually artificial reverb or delay.

wet/dry mix. The parameter that controls the blend of the un-effected (dry) signal and the processed (wet) signal output by an effects device.

White Book. One of a set of “Rainbow Books” with colored covers containing the Sony/Philips-developed specifications for different optical compact disc formats. The White Book contains the specification for Video CD.

white noise. A type of random noise signal used for testing purposes, containing equal energy per frequency. Since the number of frequencies doubles with each octave, white noise sounds somewhat like hiss because the sonic energy increases in the higher octaves.

wide cardioid (a.k.a. subcardioid). A polar pattern that falls between omnidirectional and cardioid patterns. See Figure W.1.

Figure W.1. The wide cardioid polar pattern is more directional than an omnidirectional pattern, but it picks up more sound from the rear than a true cardioid pattern.

width. The characteristic of stereo spaciousness or the “spread” of a sound across the stereo field. A sound with a narrower width will seem to come from a single location or area in the stereo field, whereas one with a wider width will seem to fill the stereo field.

wild time code. Time code that isn’t resolved or synchronized to a reference source. One example is time code on a video that isn’t synched to the frame rate. Wild time code can make it difficult to sync audio to the video in post-production.

window. A visual interface element of a GUI operating system, somewhat like a screen within a screen that can be “opened” or accessed to display data, an editor, a process, or other information for the user.

Windows. A family of GUI-based operating systems created by Microsoft and first introduced in 1985 for personal computers. There are many different versions, each of which added an extensive array of features, enhancements, and capabilities:

windscreen. A covering, usually foam, that slips over a microphone and shields it from picking up wind noise.

wireless. A system thattransmits audioor data using radio or infrared waves rather than physical cable connections.

wizard. 1. A “helper” program that guides a user through installing or using another piece of software, usually with simple step-by-step instructions and diagrams/graphics. 2. A help function in a hardware device that assists the user in finding the best presets for a particular application.

WMA. Windows Media Audio. An audio data compression format originally developed by Microsoft to compete with MP3. WMA is widely used on portable music players. Later versions, such as WMA 10, added features such as stereo 24-bit/96 kHz support and 5.1 and 7.1 surround support.

woodshedding. Slang term for practicing, usually a musical instrument.

woofer. The low-frequency driver or transducer in a multi-driver speaker system.

word. A grouping of data bits. In digital audio, a word is one complete sample, regardless of the bit resolution.

word clock. 1. A high-resolution digital signal used to control the sample rate of a piece of gear, or the speed at which digital words are transmitted. 2. A type of I/O connection found on some digital audio gear that is used to synchronize the piece of gear or the entire system to an external master clock.

word length. The bit depth, or number of bits, in a word.

workstation. A term that is applied to a wide variety of studio sound creation and manipulation devices, including computer and standalone DAWs, keyboards with built-in sequencers and audio capabilities, MPC-style “groove” devices, desktop computer rigs, and more.

WORM. Write Once, Read Many. A type of CD drive and media that “closes” the disc after it is written or burned, at which point no more data can be added or changes made.

wow. A slow change in pitch or frequency due to speed fluctuations (one or two per second) in a turn-table, tape recorder/player, or other mechanical playback device. See also flutter.

wrapper. Software that “encloses” another piece of software and allows it to run on another platform. Wrappers are commonly used to make plug-ins of one format compatible with another format without rewriting the actual plug-in code. For example, a wrapper might be used to allow a VST-format plug-in to run under RTAS format in Pro Tools.

write. 1. To “burn” or record data or audio to a recordable CD or DVD. 2. To store data on a hard drive or other media. 3. To create a breakpoint or curve in a dynamic automation system.

write protect. To “lock” a piece of media, a drive, or a file so it cannot be modified or overwritten.