system with the ‘.m4a’ filename extension. M4A can produce better audio quality than MP3 using less physical space for the files.
MHz (Mega Hertz)
One million cycles per second.
Midrange
The middle three octaves (more or less) of the audio band, where the ear is most sensitive, usually between
Mono (monaural)
The operation of an amplifier in one channel for both input and output. Can refer to
an amplifier with only one channel of amplification or operating in bridged mode. For
MP3
A file format with a sound data compression system. MP3 is the abbreviation of Motion Picture Experts Group 1 (or
Mute
A control found on receivers, and some mixers or signal processing units that silences (mutes) a signal path, or output.
O
Ohm
Measure of resistance to current (impedance). The lower the impedance of a speaker, the harder it is to drive.
P
PCM (Pulse Code Modulation) Pioneering form of digital recording.
R
RDS (Radio Data System)
RDS tuners can automatically tune in stations according to the types of music (or talk) they broadcast. RDS also enables a receiver to display text messages and even graphics (usually call letters and format information) that many FM stations include on a
RF (radio frequency)
An alternating current or voltage with a frequency (or carrier wave) above about 100kHz. It is called radio frequency because these frequencies have a capacity to be radiated as electromagnetic waves by radio (and television) stations.
Rip (ripping)
Using a software program that “grabs” digital audio from a compact disc and transfers it to a computer hard drive. The integrity of the data is preserved, because the signal does not pass through the computer sound card, and need not be converted to an analog format. The
RMS (Root Mean Square)
A formula that provides a reasonably accurate means to measure and compare continuous AC power. The use of this measure is preferred when matching system components, like amplifiers and receivers.
S
S/PDIF (SPDIF) (Sony/Philips Digital Interface)
Astandard
38EN