Labels:text | screenshot | font | black and white | document OCR: Note: terms followed by an asterisk (*) have individual articles. head - The device in a tape recorder that applies the recording signal to the tape, or reads it for playback. impedance - Opposition or resistance to the flow of electrical current. The rated impedance of a loudspeaker is an average, since the impedance depends on the frequency of the signal. integrated amplifier - An amplifier containing the preamplifier and the power supply in one unit. LED (light-emitting diode) - Solid-state devices that glow when electric current is applied. loudness compensation - A tone-control process that boosts low frequencies at low volume levels, in an attempt to compensate for the ear's insensitivity to quiet bass sounds. midrange - Frequencies in the range spanned by the human voice, from approximately 200 to 2,000 cycles per second. MD (MiniDisc) - A miniature digital audio disc, based on perceptual coding. A play-only MD is a miniature CD. A recordable MD is a magneto-optical disc. monophonic, monaural - Recording or playback involving only one channel of multipath - Reception of one or more reflected signals along with a direct sound. broadcast signal, producing distortion in stereo FM and ghost images multiplex - A method of accommodating two channels of information on one in television. carrier, for example, two channels of sound in one FM broadcast. perceptual coding - An approach to digital coding that records only the portions of a sound or picture that are believed to be audible or visible. phase - The relative timing of two signals. If signals are "in phase," they are precisely synchronized. If loudspeakers are wired "out of phase, " one is "pushing " when the other is "pulling ". preamplifier - The portion of an amplifier* that amplifies phono signals and includes most operating controls. power amplifier - The portion of an amplifier* that produces the high current levels needed to drive a loudspeaker. quadraphonic - Surround-sound reproduction involving the recording and playback of four channels of sound. quantization - The representation of a continuous quantity, such as a sound wave, by a series of numeric values. receiver - Generally speaking, any device that receives broadcasts. h Hi-Fi equipment, an integrated amplifier and radio tuner combined in the same chassis. resonance - The natural tendency of a device to vibrate at a specific frequency. Un wanted resonances in loudspeakers, for example, alter the sound by producing excessive response at some frequencies rumble - Low-frequency noise caused by vibration of the motor and bearings of a turntable . sampling - Part of the process of digital recording dissection of a signal in time, preparatory to quantization. selectivity - A measure of a tuner's ability to receive stations at closely spaced frequencies without mutual interference. signal - A sound wave , transmitted as an electrical waveform or its digital representation. S/N ratio (signal-to-noise ratio) - The range, usually expressed in decibels, between the loudest sound a recording medium can accommodate and its background noise level. stereophonic - Sound reproduction that uses two or more channels in order to represent the size or spatial distribution of sound sources surround - Sound reproduction that surrounds the listener with sound, as in quadraphonic recording and reproduction. THD ( total harmonic distortion) - A measure of all of the spurious signals added by a sound-reproducing device. tone control - A method of altering the timbre of reproduced sound by increasing or decreasing the amplification at either high or low frequencies. track - The area on a tape where a signal is recorded. tracking force - The down ward force applied to a stylus to maintain uniform contact with the undulating groove wall. transducer - A device that changes a signal to a different physical form while maintaining its pattern : as in the phonograph cartridge, which trans forms stylus motions into electrical signals, or the loudspeaker, which transforms electrical signals into sound waves. transport - The portion of a tape recorder that moves the tape past the heads at constant speed. treble - The highest audible frequencies, between approximately 2,000 and 20,000 cycles per second. tweeter - A small loudspeaker that reproduces high frequencies. watt - A unit of electrical or acoustical power. Electrical power is the product of voltage and current. Acoustical power is proportional to sound-pressure intensity. woofer - A large loudspeaker that reproduces low frequencies. wow - Slight variations in the speed of a tape or record player, causing the musical pitch to wobble.
