Lossless compression

A system for reducing the number of data bits (density) in a musical signal without corrupting the original.

M

M4A

The audio file format used by Apple in their iTunes Music Store often appears on your 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 160Hz-3kHz.

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 low- frequency amplification applications, it provides better phase coherence and less distortion than stereo operation.

MP3

A file format with a sound data compression system. MP3 is the abbreviation of Motion Picture Experts Group 1 (or MPEG-1) Audio Layer 3.With the MP3 format, one CD-R or CD-RW can contain about 10 times more data than a regular CD.

Mute

A control found on receivers, and some mixers or signal processing units that silences (mutes) a signal path, or output.

O

Ohm

ish

Measure of resistance to current (impedance).

ngl

The lower the impedance of a speaker, the

E

 

harder it is to drive.

 

 

Glossary

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 sub-carrier signal

 

within their normal broadcast signal. Some RDS

 

equipped tuners can even override with traffic

 

alerts or emergency broadcasts, during playback

 

of other media - CD MD, or cassette.There are

 

other useful features too, many of which are

 

offered by the growing number of RDS stations.

 

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

 

digital-to-digital transfer creates a WAV file that

 

can then be converted into an MP3 file.

 

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Philips WAC7505 user manual M4A, MP3, Harder it is to drive, Not be converted to an analog format.The