Audio Terminology And Definitions Dictionary

 

Back EMF  The rear electromotive force from loudspeaker drive units.

 

Back Surround Speaker     A single speaker or pair of speakers placed behind the listening position in a 6.1 or 7.1 channel home theater system.

 

Baffle    The flat or mildly curved front panel of a conventional loudspeaker enclosure that holds one or more active drivers. Some loudspeakers have drivers mounted on more than one surface. Technically, each surface on which a driver is mounted is a baffle, but the term is usually reserved to the surface holding the most drivers.

 

Balanced  In a balanced electrical circuit the positive and negative conducting paths are referenced to earth equally. The advantages of balanced operation are improved signal to noise ratio and distortion compared with unbalanced circuits. In analog signal transfer, the XLR connection is balanced.

 

Band  A continuous range of frequencies that defines a circuit's ability to transmit that range without adding artifacts. For example, the band of bass frequencies is usually defined as beginning at 20 Hz and extending to approximately 200 Hz.

 

Bandwidth  A range of frequencies defined by its highest and lowest limits. The audio bandwidth of human hearing has traditionally been defined as 20 Hz to 20 kHz. In pure electronic terms, the width of a communication channel, measured as frequency (in cycles per second, or Hertz). A channels bandwidth is a major factor in determining how much information it can carry.

 

Bass  The lowest audible band of frequencies, running from about 20 Hz to 200 Hertz.

 

Bass Reflex   A type of loudspeaker enclosure in which a vent or port from inside the cabinet connects the "backwave" from the woofer's rear surface to the outside environment. This vent "loads" the woofer to augment bass response. Unless very carefully configured, a bass reflex enclosure may not provide the same accuracy as an acoustic suspension enclosure, even though the bass reflex enclosure may well be more efficient in generating bass frequencies.

 

Belt-Drive  Turntables fitted with a belt between the drive motor pulley and the record-supporting platter. A belt is used to isolate the pickup cartridge from motor noise. It is traditionally regarded as the best way to maintain rotational speed stability at audio frequencies. 

 

BER  Bit Error Rate. The ratio of received bits that are in error, relative to a specific amount of bits received; usually expressed as a number referenced to a power of 10.

 

Bias   A high frequency AC signal applied to the record head of a tape recorder to help it record a wide bandwidth linear signal onto magnetic tape.

 

Binaural  Associated with a type of recording made using a dummy head fitted with microphones located at the position of the two ears. Replay of binaural recordings via headphones is considered to enhance a sense of 'out of the head' definition in contrast to the normal 'inside the head' sound using headphones.

 

Binding Post  A device for clamping or holding electrical conductors, such as wire, in a rigid position.

 

Bipolar     A loudspeaker that radiates equal amounts of energy with the same polarity in two opposite directions (i.e., in phase). The compressions and rarefactions that constitute sound waves move outward from each side of the enclosure symmetrically (i.e., both sides of the enclosure produce a positive pulse or a negative pulse at the same time). (See also: dipolar; also refers to a particular type of transistor.)

 

Bitrate    When used as a specification for compressed audio files, bitrate is the average amount of data required to store one second of music (expressed in kilobits per second, or Kbps). Some codecs like MP3, WMA, and AAC allow files to be encoded at different bitrates. Generally, as the bitrate decreases, so do the sound quality of the resulting file and the amount of memory required to store it.

 

Bitstream A bitstream refers to binary bits of information (1s and 0s) that have been transferred from one device to another. Specifically, bitstream refers to the transferring of a digitally encoded Dolby Digital or DTS-related compressed audio signal from a source component (such as a DVD or Blu-ray player, or an HD-Cable or HD-Satellite Box) to a surround processor for decoding and distribution to the amplifier. Bitstreams are usually transmitted via optical or coaxial digital links, or an HDMI interface.

 

Bitstream Converter     A one-bit or low-bit A/D and D/A oversampling conversion method developed by Philips in which the audio signal is represented through either PDM (pulse density modulation) or time averaging at a frequency of 11.3 MHz.

 

Bi-Wiring    A wiring configuration between amplifier and loudspeaker that uses two separate signal paths from the amp's output terminals to separate inputs for bass and higher frequencies on the speaker end. The sonic benefits of bi-wiring are often vehemently debated.

 

Blu-ray Regional Codes   Blu-ray discs are coded in a similar fashion to the system used for DVDs.

However, instead of the eight official regions used for coding DVDs, Blu-ray Discs have only three regions, designated as follows:

·   Region A: U.S., Japan, Latin America, East Asia (except China)  
·   Region B: Europe, Africa, Australia, New Zealand
·   Region C: China, Russia, remaining countries  

Note that many Blu-ray discs do not have regional coding and may play on any Blu-ray machine.

 

BMP (Windows Bitmap Image)   A standard format used for storing images on Windows-based PCs. BMP images can either be compressed or uncompressed. This type of file sometimes appears with the .dib extension.

 

Bridged Mode  Some amplifiers have the ability to be operated in a "bridged mode," which inverts one channel of a stereo amplifier and places it in parallel with the other channel, in effect turning the amplifier into a mono unit. This increases the amplifier's output voltage, which results in up to triple the rated output power available in stereo mode. Note: When operating an amplifier in "bridged mode," use only nominal 8 Ohm loudspeakers.

 

Bright  A term often used to describe the sound of a component (speaker, amplifier, phono cartridge, etc.) that exhibits an accentuated or elevated midrange/treble sonic characteristic.