| Term | Definition |
|---|---|
| D'Appolito | Joe D'Appolito is credited with popularizing the MTM (Midrange-Tweeter-Midrange) type of speaker. |
| DAC | Digital to Audio Converter. Converts a digital bitstream to an analog signal. Can be a separate "box" that connects between a CD Transport or CD Player and a pre-amplifier. Damping (Damping factor, etc.): Refers to the ability of an audio component to "stop" after the signal... Read More |
| Decibel (dB) | Named after Alexander Graham Bell. We perceive differences in volume level in a logarithmic manner. Our ears become less sensitive to sound as its intensity increases. Decibels are a logarithmic scale of relative loudness. A difference of approx. 1 dB is the minimum perceptible... Read More |
| Diaphragm | The part of a dynamic loudspeaker attached to the voice coil that moves and produces the sound. It usually has the shape of a cone or dome. |
| Diffraction | A change in the direction of a wave front that is caused by the wave moving past an obstacle. |
| Dipole | An open-back speaker that radiates sound equally front and rear. The front and rear waves are out of phase and cancellation will occur when the wavelengths are long enough to "wrap around". The answer is a large, wide baffle or to enclose the driver creating a monopole. |
| Direct Current (DC) | Current that moves in only one direction. |
| Dispersion | The spreading of sound waves as they leave a source. |
| Distortion | Anything that alters the musical signal. There are many forms of distortion, some of which are more audible than others. Distortion specs are often given for electronic equipment, which are quite meaningless. As in all specifications, unless you have a thorough understanding of... Read More |
| DIY | Abbreviation for Do - It - Yourself. In audio, the most common DIY is building speakers but some hobbyists build everything from pre-amps to amplifiers to DACs. |
| Dolby Digital | Is a five-channel system consisting of left, center, right and left rear, right rear channels. All processing is done in the digital domain. Unlike Dolby Prologic in which the rear effects channels are frequency limited to approx. 100-7000Hz, Dolby Digital rear channels are... Read More |
| Dolby Digital EX Surround | Also referred to as Dolby Digital 6.1, adds a rear, center channel to the existing left, center, right and rear speakers. This format requires a 6.1 processor or receiver and DVDs that are 6.1 encoded. |
| Dolby Prologic | Is a four-channel system consisting of left, center, right and rear channel; (the single rear channel is usually played through two speakers). |
| Dome Tweeter | A high frequency speaker with a dome-shaped diaphragm. A high frequency speaker with a dome-shaped diaphragm. |
| Double (Dual) Voice Coil (DVC) | A voice coil with two windings generally used in woofers. Each voice coil can be connected to a stereo channel, or both voice coils can be wired in parallel or series to a single channel. |
| DSP | Digital Signal Processing. DSP can be used to create equalization, compression, etc. of a digital signal. |
| DVD | Digital Video Disc or Digital Versatile Disc. A new standard that seeks to combine better-than-laser-disc quality video with better-than-CD quality audio in a disc the size of a CD. Requires a DVD player, which has become mass-market consumer product eradicating... Read More |
| Dynamic | The dynamic driver is the most common type used in headphones. This operating principle consists of a stationary magnetic element affixed to the frame of the headphone, which sets up a static magnetic field. The magnetic element in headphones is typically composed of ferrite... Read More |
| Dynamic Headroom | The ability of an audio device to respond to musical peaks. For example, an amplifier may only be capable of a sustained 100 watts, but may be able to achieve peaks of 200 watts for the fraction of a second required for an intense, quick sound. In this example, the... Read More |
| Dynamic Range | The range between the loudest and the softest sounds that are in a piece of music, or that can be reproduced by a piece of audio equipment without distortion (a ratio expressed in decibels). In speech, the range rarely exceeds 40 dB; in music, it is greatest in... Read More |
