Term	Definition	Demo
A/V receiver	Combines the following functions in one device: audio- and video-signal switcher; surround sound decoder; multichannel amplifier; preamplifier, including tone controls and other effects; and radio tuner.
Algorithm	A step-by-step procedure for solving a problem or accomplishing a task, usually by using a microprocessor or DSP (see below). In digital audio, algorithms are often used for sound processing, data compression and surround sound en-/decoding.
Center channel	A channel driving a loudspeaker located midway between the front left and right loudspeakers. It does most of the work in movie and television audio, anchoring dialogue to the screen. In multichannel music, the featured artist can have a private channel. Must sound as good as, and as similar as possible to, the left and right loudspeakers. In automobiles it is especially important to solidly anchor the center portion of the front soundstage for both the driver and the passenger. See Channel.
CMMD™	Working in collaboration with metallurgy specialists, the resourceful Infinity transducer engineers identified a special combination of materials that exhibit a remarkably useful set of mechanical properties. Infinity’s new Ceramic Metal Matrix Diaphragms are much stiffer than standard metal diaphragms, moving the natural modes significantly upwards in frequency. At the same time, CMMD™ cones have more damping than metal cones, making this an excellent cone material for all transducers: woofers, midranges and tweeters.	Click Here for Interactive Demo
D2B Optical	This Digital Data Bus (D2B) was developed by Becker in 1995 in collaboration with Philips and C&C Electronics. D2B Optical was the first fiber-optic data transmission system to be used for audio and control data in vehicles with a data rate of approximately 5Mbit/s.
DAB	DAB (Digital Audio Broadcasting) is a technology standard for broadcasting audio using digital radio transmission. The term digital radio was first used for DAB in 2001.
Discrete	In the audio context, discrete refers to sound recordings in which all channels are stored separately. Each channel is completely independent of each other channel.
Discrete 5.1 media	Discrete 5.1 media include DVD-Audio, DVD-Video and DTS-CDs. The popular 5.1-channel digital formats, like Dolby® Digital and DTS®, have three front channels (left, center and right) and two surround channels, all of which are full bandwidth, and a “.1” channel that is low-frequency only, and used for occasional special effects.
Discrete Logic 7® technology	See Logic 7 technology.
Dolby® Digital (audio coding 3/AC-3)	An audio signal encoding/decoding system, developed by Dolby Laboratories, that uses perceptual coding to reduce the data rate required to transmit, and the amount of digital space required to store, digital audio signals. It can store mono, stereo and multichannel formats. Different consumer and professional versions use different amounts of compression and, therefore, have different levels of audio quality. See Perceptual coding.
DRM	DRM (Digital Radio Mondiale) is a digital radio system for short-, medium- and long-wave. Compared to conventional AM radio, DRM can fit more channels, at higher quality, into a given bandwidth.
DTCP	DTCP (Digital Transmission Content Protection) is a digital encryption method that enables the transport of content-protected audio and video signals via a digital transmission channel from a source (e.g., DVD player) to an end point (e.g., amplifier or display).
DTS®	An audio signal encoding/decoding system, developed by DTS, Inc., that uses perceptual coding to reduce the data rate required to transmit, and the amount of digital space required to store, digital audio signals. It can store mono, stereo and multichannel formats. Different consumer and professional versions use different amounts of compression and, therefore, have different levels of audio quality. See Perceptual coding.
DTS-CDs	DTS-CDs are music CDs produced with five discrete channels for playback in multichannel format through suitable decoders.
DVC (Dynamic Volume Control)	In car audio systems, this adjusts the volume and frequency response of the playback to compensate for the auditory masking effects of road, aerodynamic and mechanical noises in a moving vehicle.
DVD, DVD-Video	DVD initially stood for Digital Video Disc but, now that there are several uses for the medium, it is more popularly known as the Digital Versatile Disc.
DVD-Audio	An audio version of DVD, in which multiple digital audio channels can be stored in uncompressed PCM form, or using a lossless compression algorithm (the digital audio signals are reconstructed without alteration). The massive storage capacity of DVD allows for many options.
DVD-Video	DVD with a special directory structure for files that contain uncompressed or compressed audio signals, and still or moving images plus optional subtitles. Usually protected by various digital copy protection measures.
EMC	EMC (Electromagnetic Compatibility) refers to electromagnetic disturbance that occurs when different electronic devices are connected. See EMI.
FEM (Finite Element Method)	FEM is a form of computer-aided modeling used in engineering. It is used to solve problems in many disciplines. The area or volume to be analyzed is divided into a large number of small elements, and the behavior of each element is modeled by solving the large system of simultaneous equations. FEM is used to predict the behavior of materials and assemblies during the design phase, speeding the process and allowing for experimenting with different alternatives without having to construct prototypes.
HD Radio™	One of DAB’s competitors, HD Radio is a digital radio system for transmitting audio on the FM and AM bands. It was developed in the USA by iBiquity, a company founded specifically to develop this technology. In contrast to DAB, HD Radio is not only a digital system, but one that can be operated as a hybrid system with analog AM and FM radio.
Midrange	Frequencies between 300Hz and 3000Hz. See Midrange driver.
MLP	MLP (Meridian Lossless Packing), also known as Packed PCM (PPCM) or Dolby MLP Lossless™, is a proprietary lossless compression algorithm for digital sound recordings. The format was specifically designed for high-resolution audio data and is mandatory for DVD-Audio.
MMD™	Derived from our patented CMMD™ technology, Infinity's new Metal Matrix Diaphragms (MMD™) continue the Infinity tradition of using advanced materials to improve sonic accuracy. By adonizing both sides of an aluminum core, we're able to significantly improve cone performance and outperform cones made of traditional materials.
MOST® (Media Oriented Systems Transport)	Digital network for the optimized transmission of data (particularly all multimedia data used in vehicles) via fiber-optic or electric cables. As with D2B Optical, the defining characteristic of MOST is synchronous data transmission, which coordinates sound and image signals. Many European and Asian vehicle manufacturers use MOST. The system was developed in 1997 by the MOST Cooperation, a consortium of Harman/Becker, Audi, BMW, DaimlerChrysler and SMSC; the consortium also works with other industry partners.
MPEG (Motion Picture Experts Group)	MPEG develops standards for the compression of digital audio and video signals. There are different MPEG standards, depending on the application. MPEG-2 is the video standard used for DVDs; the correct name for the popular term MP3 is MPEG-2 audio, layer 3.
PCM	A straightforward, uncompressed coding method in which analog signals are sampled at regular intervals, and each sample is represented by a digital number representing the amplitude at that instant in time. Sampling is done at a frequency at least two times the highest frequency of interest, and the digital number must have a sufficient number of bits to capture and reconstruct the essential qualities of the audio signal (dynamic range, low distortion and noise, etc.). For example, typical CDs are recorded using a sampling frequency of 44.1kHz, using a 16-bit digital number. See Bit, Compression.
R.A.B.O.S.™	Room Adaptive Bass Optimization System (R.A.B.O.S.) utilizes a single band of parametric equalization to tame the most prominent room, mode or bass peak. These bass peaks exaggerate the sounds at their frequency resulting in bass performance that is often sloppy or boomy. By reducing the level of this peak, you are able to hear deeper, more detailed low frequencies. The sound-pressure-level meter included with the R.A.B.O.S. accessory kit allows the listener or installer to easily make the measurements required in order to properly calibrate the RABOS settings for your particular listening room.	Click Here for Interactive Demo
SDARS	SDARS (Satellite Digital Audio Radio Services) is an umbrella term for satellite-supported radio systems in North America. There are currently two different systems: Sirius Satellite Radio and XM Radio.
Surround Sound 5.1	A multichannel sound system, with five main channels and a low-frequency effects (LFE) subwoofer channel. Surround sound was developed from cinema technology. All six channels are discrete, meaning they are stored and played back separately.
Surround Speaker	A speaker typically matched in size to the midrange speakers used in a system. Its primary function is to “carry” sound throughout the listening area so that the listener feels enveloped in sound. The size and material of a surround speaker should closely match the midrange speakers in the system; this ensures that the “moving” sound doesn’t waver, or change timbre, thereby guaranteeing a rich, full-range surround-sound experience.
Tweeter	A loudspeaker driver optimized to reproduce high frequencies, typically above about 2kHz to 4kHz.
Woofer	A loudspeaker driver designed to reproduce bass frequencies.