Editing Audio system measurements (section)

=== Mechanical ===
; [[Wow (recording)|Wow]] and [[Flutter (electronics and communication)|flutter]] : These measurements are related to physical motion in a component, largely the drive mechanism of [[analog signal|analogue]] media, such as [[vinyl record]]s and [[magnetic tape]]. "Wow" is slow speed (a few Hz) variation, caused by longer-term drift of the drive motor speed, whereas "flutter" is faster speed (a few tens of Hz) variations, usually caused by mechanical defects such as out-of-roundness of the [[capstan (tape recorder)|capstan]] of a tape transport mechanism. The measurement is given in % and a lower number is better.

; Rumble : The measure of the low frequency (many tens of Hz) noise contributed by the [[turntable]] of an analogue playback system. It is caused by imperfect bearings, uneven motor windings, vibrations in driving bands in some turntables, room vibrations (e.g., from traffic) that is transmitted by the turntable mounting and so to the phono cartridge. A lower number is better.