Object@Emagic Logic Audio term. In the Arrange window, a general term for sequences or folders. In the environment, it also applies to instruments, faders, mixers, keyboards, monitors, Audio Objects, etc.@Octave@Musical interval. The relationship between the pitches of two musical tones, where the frequency of the second is exactly double that of the first. (The name "octave" derives from the fact that this interval corresponds to the eighth degree of the standard, seven-tone diatonic scale. To put it another way, an octave is the distance between one "C' and another on the piano keyboard.) Since the octave corresponds to a proportional relationship of frequency between two notes (as do all other musical intervals, the fifth, fourth, semitone, etc.), the actual frequency difference represented by the span of each successive octave above a given note varies. For example, the series of octave intervals above "A" 440 Hz are at the frequencies of 880, 1760, 3520 Hz, etc.@OEM@Original Equipment Manufacturer. A company that manufactures a component, which is in turn incorporated into another company's product. For example, Apple, Compaq, and most other personal computer manufactures do not manufacture their own diskette or hard drive mechanisms; they purchase them from specialized companies like Quantum, Seagate, Connor, etc. These same OEMs may also sell similar (but not always identical) drive mechanisms to other manufacturers.@Offset, Start Time@The adjustment of the playback of one recorder with respect to a time reference received from another, particularly in the context of SMPTE timecode synchronization. The user of a MIDI sequencer or digital audio program specifies a Start Time, or Offset, for the beginning of the file. When this SMPTE time code reference is received, the sequence, project or Session will begin to play back. All other time code indications seen within the file are calculated relative to this Start Time. If the initial Offset is later changed, audio or MIDI events within the file will still be in the same locations relative to the file's beginning, however their displayed SMPTE references will be recalculated accordingly. See also SMPTE.@Ohm@A unit of measure for electrical resistance or impedance. The resistance of a circuit where the electromotive force of one volt maintains a current of one ampere. Named for Georg Simon Ohm, German physicist. Also abbreviated with an omega symbol. See also Impedance.@OMF@Open Media Framework. A file format standard developed between various manufacturers (especially Avid) to promote a common format for interchange of data between various computer-assisted, non-linear editing systems for video and audio.@OMF Tool@Software product, which facilitates transfers between Digidesign's audio workstation formats and Open Media Format standards (see definition). Permits document interchange with OMF-compliant video editors, in particular Avid's Media Composer and Audio Vision. Supports EDLs (Edit Decision Lists).@OMFI@Open Media Format Interchange. A file format used as an intermediate, interchange format for the transfer of digital audio, video and EDLs (Edit Decision Lists) between OMF-compliant editing systems, particularly those from Avid and Digidesign. See OMF, OMF Tool.@Omnidirectional@Describes a microphone that is equally sensitive to sounds coming from all directions. Unlike Directional microphones (cardioid, supercardiod, etc.), omnidirectional microphones do not exhibit any Proximity Effect (bass frequency boost at close distances). Also, since they don't require the acoustic delay circuit used to achieve the desired polar response pattern in most directional microphone designs, their frequency response can be made very even ("flat"). For this reason, in studio conditions where leakage from other sound sources is not a problem, many engineers will switch professional recording microphones to the omnidirectional pattern, if a very natural sound is desirable. The term Omindirectional may also be used to describe a sound source, which radiates equally in all directions. See also Unidirectional, Cardioid, Proximity Effect..@OMS@Open MusicSystem. Formerly known as Opcode MIDI System. A standard promoted by MIDI software and interface manufacturer Opcode, intended to simplify the management of large MIDI installations and the routing & naming of MIDI gear. Much of Opcode's software requires OMS in order to operate. In a manner similar to, but much more comprehensive than Apple's MIDI Manager, OMS acts as an intermediary between MIDI programs and the serial port, MIDI interface and modules, mediating a common access system for diverse programs operating concurrently. Configured using the OMS Setup utility. Supported by Digidesign, Emagic, Steinberg, OSC, and many other MIDI software developers, as well as Microsoft and Apple. See also OMS IAC Driver.@OMS IAC driver@A software driver which forms part of Opcode's OMS version 2.01 and higher (see definition). These Inter-Application Communication drivers permit various MIDI and audio programs (which are OMS-compliant) to run simultaneously under Apple's operating system 7, communicating with each other through virtual "ports". See also OMS.@One-Off@Audio and computing industry term. A single copy of a piece, transferred to a recordable CD (CD-R, see definition).@Online@In Sound Designer, Pro Tools, Deck and Session, "Online" specifies that the program is looking for incoming SMPTE timecode (which arrives as MIDI TimeCode via SMPTE-MIDI interface) before starting playback, and will jump to the appropriate location and begin playback once that timecode reference is received. See SMPTE TimeCode.@Op Amp@Operational Amplifier. A stable, high-gain DC-coupled voltage amplifier with a high input impedance and low output impedance, and a high frequency bandwidth. Commonly used in analog electrical circuits, in particular for filtering, power supply regulation, voltage amplification.@Opcode@MIDI software and hardware manufacturer. Studio 3,4,5, MIDI Translator and other MIDI interfaces, the Vision family of MIDI sequencers, Overture musical page layout program, Galaxy MIDI Editor/Librarian, and a variety of other products. Authors of OMS (also known as Open Music System, or Opcode MIDI System), which facilitates inter-application communication between MIDI programs, and management of MIDI configurations through software; supported by Apple and Microsoft.@Optical Disk, M-O Disk, Magneto-Optical Disk, MO@A removable disk type used for computers, samplers and hard disk recorders. Available in various cartridge sizes and capacities. While optical disks are slower than ordinary magnetic hard disks, they offer a large amount of removable storage capacity at a relatively low cost per megabyte, and data shelf life of up to ten years, versus five for magnetic media. Magneto-optical, or M-O disks, record and erase data onto the metallized plastic substrate on boths sides of a rigid plastic disk, using a magnetic bias field to change the polarity of a coating on its surface. This coating is only susceptible to having its polarity changed when a given point has been heated to 150û by a low-intensity laser. To read back data from the M-O disk, a laser and optical sensor register the changes in reflectivity caused by the different polarities that were applied. See also CD-ROM, Dye-Polymer, SyQuest.@Orange Book@Document of standards developed by Sony and Philips to define disk formats and writing methods for M-O, magneto-optical disks (Part I), and especially for recordable CDs, CD-R (Part II). The Orange Book standards also define multisession recording to a CD (used by Kodak for its Photo CD format, also known as Beige Book), by which data can be incrementally added (but not erased) until the disk is full. With the appropriate software most professional CD-Rs can write discs in Yellow Book, Beige Book and Red Book data formats, as well as others. See also Compact Disc, CD-ROM, Photo CD, CD-R.@Orb@A removable disk drive for personal computers, introduced in 1998 by Castlewood Systems. Uses a 3.5" cartridge, and offers a fast 12.2 MB/second maximum sustained data transfer rate. Average seek time 10-12 milliseconds. Capacity is 2.2 GB per cartridge - drives are under $200, and cartridges under $20. Available with either USB or FireWire (IEEE 1394) connection, as well as SCSI, EIDE (PC) and parallel port (PC). First units shipped in late 1998.@Oscillator@An electronic circuit that can produce a periodic waveform (in other words, a regular, repeating pattern of voltage levels). Most oscillators used for generating audio signals can produce a variety of frequencies (the number of repetitions of the wave per second), and waveforms (different patterns of voltage displacement, as seen on an oscilloscope, which correspond to the diverse harmonic spectrums of different sounds). In early electronic musical instruments, the frequency of electronic oscillators was controlled by varying the amount of DC voltage applied to the circuit; modern "analog" synthesizers use digital signals to control the frequencies of oscillators (as well as time-variant filters and amplifiers). See DCO, VCO.@OSTA@Optical Storage Technology Association, a trade association of manufactures involved with CD media and recorders/players. This group conducts extensive media reliability tests for manufacturers, and seeks to define standards which will guarantee compatibility of CD-R media with units from different manufacturers.@Outro@1) Musical Term. A repeating figure played as the last section of a musical piece. The opposite of an Intro (introduction); especially a repeating phrase (a "vamp") played during a fade out, which may be musically related to the Intro.
2) Video production term. A summary, or closing segment at the end of a video piece; the opposite of an Introduction.@Overdubbing@The process of recording additional audio tracks, while monitoring playback of existing material on the same tape.@Oversampling@A method used in digital audio systems to improve the quality of anti-aliasing filtering; reduces intermodulation distortion and phase problems, by using digital filters with more gradual slopes. The effective input sampling rate is multiplied by a given factor, for example 4x, 64x, 128x, etc., so that a simple, single-order digital lowpass anti-aliasing filter can be used for eliminating signal components above the Nyquist Frequency. Decimation is then applied to achieve the final sampling rate, used for storing the audio data. Oversampling is also used at the D/A conversion stage of the outputs on many digital systems. If you are unfamiliar with digital audio system specs, and are comparing two alternatives, higher oversampling ratios and 1-bit sigma-delta conversion is probably indicative of higher sound quality, IF the quality of all components and other factors in the two systems are exactly equal (ha ha ha ha). See also Aliasing, Sample Rate, 1-bit sigma-delta conversion.@
