Parts Express - Tech Terms Glossary

Tech Terms Glossary

A / B / C / D / E / F / G / H / I / J / K / L / M / N / O / P / Q / R / S / T / U / V / W / X / Y / Z

Wow and flutter: Instantaneous variations in the rotational speed of the turntable platter. Also instantaneous speed changes in tape playback speed.

WRMS: Stands for the weighted root mean square, a method of using filters to give more "weight" to 4~6Hz modulations in the 3~4kHz region when making wow & flutter measurements since the ear is most sensitive to such speed fluctuations. Root mean square is a formula for deriving a virtual value from a fluctuating waveform. In contrast, sometimes wow & flutter is listed as a weighted peak (W peak value).

Xmax: The maximum linear excursion of a loudspeaker voice coil while remaining within the magnetic flux field.

Yagi: Popular design for home radio/TV antennas.

Z: The nominal electromagnetic impedance of a loudspeaker or electronic system.

Zinc-carbon: Common, standard-output battery or cell using combinations of zinc and carbon compounds to create current flow. Made for light to medium duty devices with minimal or no motors or electrically-driven components. Known for low shelf-life, and leakage after electrical discharge. Examples: AA, AAA, C, D and others.

Zoom lens: A lens system that may be effectively used as a wide angle, standard or telephoto lens by varying the focal length of the lens.

Zoom ratio: The ratio of the starting focal length (wide position) to the ending focal length (telephoto position) of a zoom lens. A lens with a 10X zoom ratio will magnify the image at the wide angle end by 10 times.