Philips NP2900 User manual - Page 42

English being played, and then downloads the title, artist, and track list. Coaxial A single copper conductor, surrounded with a layer of insulation, covered by a surrounding copper shield and finally, an insulating jacket. An unbalanced transmission line with constant impedance. In audio, this type is commonly used for low level, line signals terminated in RCA connectors. Compression In audio terms, this is a process of temporarily or permanently reducing audio data for more efficient storage or transmission. A temporary reduction in file size is called 'non-lossy' compression, and no information is lost. A permanent reduction in file size (such as with MP3 files) is called 'lossy' compression, and involves discarding unnecessary information which is irretrievably lost. D DC (direct current) Direct current or continuous current is the constant flow of electric charge. This is typically in a conductor such as a wire. In direct current, the electric charges flow in the same direction, distinguishing it from AC (alternating current). Decibel (dB) A unit of measure used to express relative difference in power or intensity of sound. DHCP DHCP stands for Dynamic Host Configuration Protocol. It is a protocol for assigning dynamic IP addresses to devices on a network. Digital A method to encode information using a binary code of 0s and 1s. Many wireless phones and networks use digital technology. Digital Audio Digital Audio is a sound signal that has been converted into numerical values. Digital sound can be transmitted through multiple channels. Analog sound can only be transmitted through two channels. Duplex (half/full) Full duplex is the ability to send and receive data simultaneously. Duplex is synonymous with full duplex. Example: when a modem operates in full-duplex mode, it can transmit data in two directions simultaneously. In half-duplex mode it can transmit data in two directions, but not simultaneously. E Encryption key An encryption key is an alphanumeric series that enables data to be encrypted and then decrypted so it can be safely shared among members of a network. F Frequency The property or condition of occurring at frequent intervals. In sound, this simply refers to the regular occurrence of compression and rarification of air that we experience as sound. Frequency Response Is the range of frequencies that a speaker reproduces, lowest frequency to the highest. While the optimal normal is 20-20,000 Hz (Hertz), the range of human hearing for individuals is often much more restricted. A good full-range speaker system however, reproduces as much of this range as possible to cover all variations. Individual drivers are limited to reproduce only that part of the spectrum for which they were made, so their response is limited, but still a necessary point to consider when designing a complete sound system. EN 41