Q—The unit used to express a filter’s selectivity. High values imply a narrow frequency band, low values, a wide frequency band.
Quantization—The PCM process in which PAM pulses are approximated to the nearest binary value available.
S/PDIF format—SeeCoaxial format.
Sampling rate — The number of times per second analog audio signals are sampled (i.e., measured) during A/D conversion. Common digital audio sampling rates are 32 kHz, 44.1 kHz, and 48 kHz.
Scene memories—Memory locations used to store mix scenes. See also Mix scene.
Shelving—A type of EQ circuit used to cut and boost frequencies above or below a set frequency. It produces a shelf-looking response curve. High and low EQs are usually of the shelving type. Contrast with Peaking.
Signal-to-noise ratio (S/N)—In an audio system, the difference between the operating signal level and the residual noise floor expressed as a decibel ratio, commonly used to measure a system’s noise performance.
Snapshot—SeeMix scene.
ST OUT—The 01V stereo output.
System Exclusive—A type of MIDI message for exclusive use with a particular device. See also Bulk Dump.
THD (Total Harmonic Distortion)—The measure of distortion introduced by an audio system relative to the audio signal expressed as a percentage. Compared to third-harmonic distortion, which is the measure of a single harmonic, total harmonic distortion is the sum of distortions produced at all harmonics.
Unity gain—A gain of one.
Wordclock—A clock signal used to synchronize the data processing circuits of all devices connected in a digital audio system. The wordclock frequency is the same as the sampling rate.