Entries found for search: MO
audio coding mode : A parameter in Dolby Digital surround-sound format which refers to the number of channels and their location in for form F/R, where F is the number of front channels and R is the number of rear channels. For example, 5-channel surround is called 3/2 mode, stereo is 2/0, and mono is designated 1/0.
atmospherics : See backgrounds.
anharmonic : See ="index.php?search=1&searchtxt=inharmonic">inharmonic.
anamorphic /: The camera/projector lens system which squeezes an image, usually originally in a 2:1 aspect ratio) onto film during shooting and "unsqueezes" it during projection. The resulting viewed image has an aspect ratio twice as wide as what was originally recorded on the film, e.g., if the image on the print is 2.2:1, the screen image will be 2.4:1. See also CinemaScope, flat(4), ‘scope.
Amplitude Modulation (AM) : The instantaneous amplitude modulation of one signal by another. This results in the formation of sidebands which contain the same information as the original signals, but translated upwards and downwards in frequency. In AM radio transmission, the audio signal is combined with a very high-frequency sine wave, called a carrier, in such a way that the amplitude of the carrier is varied in exact response to the amplitude and frequency of the signal. This is called the amplitude modulation of the carrier. The modulated carrier is transmitted at high power where it is received by radio sets that are tuned to the carrier frequency. The modulated carrier is then demodulated by a process called detection, recovering the original signal. In radio, a circuit that does amplitude modulation is also called a heterodyne.
aharmonic : See inharmonic.
active monitor A type of loudspeaker which has amplification circuitry built-in. In addition, a true active monitor system utilizes active equalization and active crossovers to precisely contour the system sound. If there is only one amplifier driving all transducers, and/or there is no active equalization or crossover circuitry, the terms powered speaker or powered monitor are preferred.
Bass Intermodulation (BIM) : Bass intermodulation is a type of distortion caused by the modulation of audible frequencies by subsonic noise.
bi-phase modulation : In SMPTE timecode generation, the electronic process that produces the signal containing the SMPTE data itself. A 1.2k Hz square wave is momentarily modulated to 2.4kHz with each new bit of location information coming from the master clock.
bridged mono : A method of combining both channels of stereo power amplifiers to create a doubly powerful single-channel (monaural) amplifier. See bridge(2).
channel mode : See MIDI mode.
common mode : Common mode refers to equal voltages induced in the two wires of a signal-carrying pair. In a balanced line circuit, the signal voltages are of opposite polarity in the two signal wires. Any voltage which appears with the same polarity on each wire is called a common-mode voltage. Usually noise, such as a 60Hz hum, is induced in audio cables equally and in the same direction, and so is a common-mode voltage. If the signal is connected to a differential amplifier input, the common-mode voltages will cancel, while the signal voltages, being of opposite polarity on each input terminal, will add together. This is the reason why balanced lines are less prone to induced noise from external influences. See CMRR.
common mode rejection : The measurement of how well a balanced circuit rejects a common mode signal. See also CMRR.
comopt : A technical term for composite optical print.
control module : The part of a synthesizer that tells the sound generators and controllers what to do to make a given note. These modules include envelope generators, LFOs, the keyboard itself, and the modulation and pitch-bend wheels. These allow control of some aspects of a synthesizer’s sound by sending signals to the sound generators and modifiers telling them now to behave. For instance, the keyboard sends a signal to the oscillator telling it what frequency to play. Also called modulation modules.
cross-mod : Cross-modulation test. A means of determining correct exposure on a track negative to result in minimum distortion on a positive print. Tests are conducted to determine the relationship of specific optical cameras to specific laboratories.
cue mode : A tape machine operating mode in which the tape lifters are defeated while the playback electronics remain operative. Used most often during editing, thus also called edit mode.
edit mode : See cue mode.
room mode : Also called standing waves, room modes come in three types: axial, along the axes of a room (front to back, side to side, floor to ceiling); tangential, or any two pairs of opposite surfaces; and, oblique modes which are the product of the reflections of all six surfaces. To calculate the frequency of a particular mode,
Where f is in Hertz, c is the speed of sound (1130 ft./sec. or 344 meters/sec.), L is the room di-mension, and n is the order of the mode. It’s not important to know the frequencies of the room mode, just how evenly spaced they are. If they are not uniformly distributed, the room will show a response peak where they are nearly coincident. The most problematic frequency range is 50Hz-150Hz. The golden ratios of height to width to length are: 1.14:1.39:1 or 1.28:1.54:1 or 1.60:2.33:1 (Bolt’s golden ratios), then the modes will be perfectly spaced and low-frequency response is smooth by design. See also standing wave.
modulation routing : The routing of a control voltage, either via hardware or software, from one module source to another.
Multi Mode : A MIDI reception mode in which a multitimbral module responds to MIDI input on two or more channels, typically playing a different patch on each channel. See MIDI Mode.
frequency modulation (FM) : (1) A change in the frequency (pitch) of a signal. At low modulation rates, FM is perceived as vibrato or some type of trill. When the modulation wave is in the audio range, FM is perceived as a change in timbre. FM synthesizers, commonly found on soundcards, create sounds using audio-range frequency modulation. See FM synthesis. (2) Frequency modulation is the instantaneous changing of the frequency of a carrier in response to a modulation signal, usually an audio waveform. As the signal voltage varies up and down as it follows the waveform, the frequency of the carrier varies up and down from its nominal unmodulated value. The FM receiver is tuned to the carrier frequency, and the received signal, after suitable conditioning, is applied to a special circuit called an FM detector, also called a demodulator or discriminator, which recovers the audio signal. See amplitude modulation.
frequency modulation distortio : Examples of frequency modulation distortion are flutter and wow, and Doppler distortion caused by the motion of rotary (Leslie) loudspeaker cones.
generator module : A synthesizer module that generates sound, usually through an oscillator.
harmonic : A frequency that is a whole-number multiple of the fundamental. For example, if the fundamental frequency of the sound is 440Hz, then the first two harmonics are 880Hz and 1.32kHz. A harmonic is the same as a partial where the partials exhibit the property that the overtones are mathematical multiples of the fundamental frequency. See harmonic series, Appendix C.