White Noise
Random noise with equal energy per frequency is called white noise. It tends to sound very bright and "hissy" due to the unique characteristics of the human ear's frequency response curve. Each ascending octave contains twice as many frequencies as the next lower one, resulting in a significant "build up" of energy in the higher octaves.

Wide-Bit Stream Processing
This technology maintains 20-bit precision through the recording process, for clearer reproduction of delicate, low-level music.


Windings
The wire in a voice coil that is wound around the former (also called a bobbin) to create a coil. Generally, any coils in a transformer, motor, or as an inductor.


Woofer (Subwoofer)
The bass and lower midrange sounds are reproduced by the woofer. To operate efficiently, a woofer's cone should be made of material that is stiff, yet lightweight. Cones made of polymers, polypropylene, light metals, or poly mixed with other materials including carbon strands and metals, provide excellent sound, and stand up to the heat, cold and moisture that car speakers face daily. Paper cones treated for moisture resistance also do a good job, and are usually very efficient. For car usage, untreated cones should be avoided.

The term "Subwoofer" came into common parlance as a result of the need for marketing departments to boost the "heavy hitting" image of their woofer products. Most such subwoofers are more dependent on the accompanying electronics than on the woofer itself. It was a campaign so successful, it is now as difficult to find a woofer as it is to find a "regular strength" antacid tablet. But as far as describing a particular type of Driver, the term is virtually worthless. The ludicrous extent to which the trend has gone is illustrated in the recent appearance of 4 inch "subwoofers."
Study the ratings, specifications, and construction of any woofer you are considering, to see if will be appropriate for your system. In constructing your system, remember to start with the goal first, then the woofer and enclosure, and finally, the amplifier. Everything must work together, and fit together as one coherent system, if you are to be successful.

One area in which the term "subwoofer" does have some authentic application is in the popularity of dedicated low range speakers called powered subwoofers (usually incorporating an amplifier and Crossover) that are used with home-theatre systems to boost the low-end response.

Wow
Wow is a relatively slow variation in the frequency of reproduced sound caused by slow speed variations in records, tape recorders, etc. Pitch fluctuations of one or two per second are classified as wow, while more rapid variations are called flutter. In specifications wow is usually rated, along with flutter, as a percentage of pitch deviation produced by these two phenomenon in a tape or phonograph machine.

X, Y, and Z

Xmax
A measure of a speaker cone's maximum Excursion (back and forth motion) in one direction while still maintaining a linear behavior (moving in a straight line with high precision). This factor is measured in inches or millimeters. Xmax is more precisely defined as the width of the voice coil that extends beyond the front plate plus 15%. This relates to how far the speaker can move in either direction without appreciable distortion.

X and Y axis
In a graph or chart showing the realtionship of one acoustical phenomenon or measurement relative to another, it is common to plot the ralionship on a chart with intersecting vertical and horizontal axis (X and Y) that graphicly shows the interaction between two or more elements, such as frequency and power in a given situation.

Y Cable or Adapter
A cable used to split a signal into two parts or combine two signals into one. The term, Y Cable is used because the cable has the appearance of the letter Y, where there are two parts joined into one, or one split into two, depending upon the purpose. Y Cables are common throughout audio as a simple and straightforward way to accomplish these two tasks.

Z
The designation of impedance, as High Z, - 47,000 ohms, or low Z, - 4 ohms

Zero Bit Detection
A circuit in a D/A converter that monitors the digital audio bit stream. upon encountering all bits low, or zero bits, the output of the D/A is disconnected from the preamp. This improves the signal-to-noise ratio specification.1

Zero Crossing
An analog waveform consists of two alternating voltage polarities (positive to negative to positive...etc.). The point where the polarity changes from positive to negative, or vice versa, is called the zero crossing. When looping a wave or editing two waveforms together, this is the ideal location for the splice as the levels of the two waves are both at zero. This eliminates the possibility of clicks or pops created by mis-matched levels, and makes for a smooth sonic transition.


Zero Output
The absence of output signal or output power