SOUND ON SOUND
A cyclical variation in replay speed which affects the pitch of the recorded material. Wow is a low-speed variation (nominally below 4Hz) which typically occurs once per revolution of the device and may be caused by an off-centre hole on a vinyl record, or a sticking tape on a reel-reel machine. Flutter is a higher speed variation (nomninally above 4Hz) and can often be perceived as a form of intermodulation distortion.
The precise timing of digital audio samples is critical to the correct operation of interconnected digital audio equipment. The 'metronome' that governs sample timing is called the Word Clock (sometimes conjoined to 'Wordclock', or abbreviated to 'Wclk'). However, word clock does more than merely beat time; it also identifies the start and end of each digital word or sample, and which samples belong to the left or right channels. Digital interfaces such as the AES3 and S/PDIF embody clock signals within the data stream, but it is often necessary to convey a discrete word clock between equipment as a square wave signal running at the sampling rate. Dedicated word clock inputs and outputs on digital equipment generally use BNC connectors.
A random signal with a flat (constant) power spectrum density, ie. equal power within any frequency band of fixed width. White noise sounds very bright (cf. Pink Noise).
A signal that has effects added. (cf. Dry)
(as in, 2-way, 3-way) - A colloquial way of denoting how many separate frequency bands are reproduced by a loudspeaker. Most are two-way systems with a woofer and tweeter, but some are three way with a woofer, midrange and tweeter.
A graphic representation of the way in which a sound wave or electrical wave varies with time.
An audio meter designed to interpret signal levels in roughly the same way as the human ear, which responds more closely to the average levels of sounds rather than to the peak levels. (cf. PPM)
Pitch modulation using an LFO to modulate a VCO. (cf. Tremolo)
The capacity of a synthesizer to play a single musical note. An instrument capable of playing 16 simultaneous notes is said to be a 16-voice instrument.
