Mackie SR244 / SR324 Owner's Manual - Page 50

Appendices Q Q is a way of stating the bandwidth of a filter or equalizer section. An EQ with a Q of .75 is broad and smooth, while a Q of 10 gives a narrow, pointed response curve. To calculate the value of Q, you must know the center frequency of the EQ section and the frequencies at which the upper and lower skirts fall 3dB below the level of the center frequency. Q equals the center frequency divided by the difference between the upper and lower -3dB frequencies. A peaking EQ centered at 10kHz whose -3dB points are 7.5kHz and 12.5kHz has a Q of 2. RCA phono jack-or RCA jack or phono jack An RCA phono jack is an inexpensive connector (female) introduced by RCA and originally used to connect phonographs to radio receivers and phono preamplifiers. The phono jack was (and still is) widely used on consumer stereo equipment and video equipment but was quietly fading into obscurity in the professional and semi-professional sound world. Then phono jacks began cropping up in early project-studio multitrack recorders, which (unfortunately) gave them a new lease on life; and since so many stereo recorders are fitted with them we decided we'd have to put a couple on the SR24•4 for your convenience. But make no mistake: the only thing that the phono jack (or plug) has going for it is low cost. RCA phono plug The male counterpart to an RCA phono jack. See above. regeneration Also called recirculation. A delay effect created by feeding the output of a delay back into itself to cause a delay of the delay of the delay. You can do it right on the front panel of many effects units, or you can route the delay return back into itself on your mixer. Can be a great deal of fun at parties. return A return is a mixer line input dedicated to the task of returning processed or added sound from reverb, echo and other effects devices. Depending on the internal routing of your mixer and your own inclination, you could use returns as additional line inputs, or you could route your reverb outputs to ordinary line inputs rather than the returns. reverberation Reverberation (or reverb) is the sound remaining in a room after the source of sound is stopped. It's what you hear in a large tiled room immediately after you've clapped your hands. Reverberation and echo are terms which can be used interchangeably, but in audio parlance a distinction is usually made: reverberation is considered to be a diffuse, continuously smooth decay of sound, whereas echo is a distinct, recognizable repetition of a word, note, phrase or sound. Reverberation and echo can be added in sound mixing by sending the original sound to an electronic (or electronic/acoustic) system which mimics natural reverberation, or worse. The added reverb is returned to the blend through additional mixer inputs. Highly reverberant rooms are called live; rooms with very little reverberation are called dead. A sound source without added reverb is dry; one with reverb or echo added is wet. RMS An acronym for root mean square, a conventional way to measure AC voltage and audio signal voltage. Most AC voltmeters are calibrated to read RMS volts. Other conventions include average volts, peak volts and peak-to-peak volts. send A term used to describe a secondary mix and output of the input signals, typically used for foldback monitors, headphone monitors or for effects devices. Mackie mixers call it an Aux Send. shelving A term used to describe the shape of an equalizer's frequency response. A shelving equalizer's response begins to rise (or fall) at some frequency, and continues to fall (or rise) until it reaches the shelf frequency, at which point the response curve flattens out and remains so to the limits of audibility. If you were to graph the response, it would look like a shelf. Or more like a shelf than a hiking boot. The EQ controls on your stereo are usually shelving equalizers. See also peaking and dipping. slap, slapback A single-delay echo without any repeats. Also see echo. solo Italian for alone. In audio mixers, a solo circuit allows the engineer to listen to individual channels, buses or other circuits singly, or in combination with other soloed signals. In Mackie mixers, activating a solo function never interferes with or interrupts any of the main or 48