72 Glossary
MD4—Owner’s Manual
Glossary
ATRAC—An acronym for Adaptive Transform Acoustic Coding. This is the compression tech-
nique used to fit the same amount of data as that of a 120 mm CD on a 64 mm MiniDisc. Using
the ATRAC system, the MD4 provides a four-track recording time of 37 minutes. ATRAC uses
established psychoacoustic principles to compress audio data to approximately one-fifth of its
original size, with virtually no loss in sound quality. The threshold of hearing principle states that
the sensitivity of the human ear is frequency dependent. Two tones of the same level but at dif-
ferent frequencies will not be heard at the same loudness. Another principle used is the masking
effect. That is, softer sounds become inaudible when louder sounds at similar frequencies are
present.
Blank Top—This is the start point of the largest unrecorded area on a disc. To record a new
song on a disc that already contains some songs, you much first locate the Blank Top. See Search-
ing for the Blank Top on page 19 for more information.
Bouncing—See Ping-Pong.
Bus—A common conductor used to collect and distribute audio signals. MD4 has four Group
buses that feed the tracks, a Stereo bus consisting of left and right channels, an AUX bus for the
AUX SEND, and a CUE bus for the cue monitor.
Clipping—The unwanted distortion effect of overloading an audio circuit with a signal that
is too large. Care must be taken when setting MD4 GAIN controls so as not to overload the
recording circuits. See Recording the First Track on page 13 for more information.
Cue—There are three kinds of cue on MD4. 1) Monitor CUE. 2) Cue List cue. 3) FF CUE See
Monitor CUE, Cue List, and FF CUE.
Cue List—The Cue List function allows you to compile a cue list (i.e., a sequence of cues for
playback) using markers. Cues are loaded into memory for continuous, uninterrupted play-
back. A new song can be created from the Cue List using the Cue List Copy function. See Cue
List Playback & Copy on page 42 for more information.
DAT—An acronym for Digital Audio Tape. DAT recorders are especially popular in recording
studios for recording the final stereo mix.
DI (Direct Inject)—A technique for connecting an electric guitar or bass guitar directly to a
mixer. The high output impedance of the guitar is matched with the low impedance of the mixer
input using a DI Box. Some instrument amplifier’s feature a DI connection.
EQ—An acronym for an audio equalizer. MD4 input channels feature three-band EQ.
EXE—An abbreviation for Execute. This appears on the MD4 display when you are prompted
to confirm a function.
FF CUE—This is the name of the disc transport button that allows you to preview at X2 or X4
normal playback speed.
Footswitch—A foot operated switch. Several MD4 transport functions and the punch in/out
function can be controlled using an optional footswitch.
Frame—An integral unit of the MD DATA disc format. One frame can hold 11.6 ms of data
(i.e., 512 samples of ATRAC sound data at 44.1 kHz). There are approximately 86 frames in a
second.
Group—A group is essentially the same as a track on MD4. That is, when an input channel is
assigned to Group 3, the signal is sent to Track 3 for recording.
Line-Level Signal—A signal in the range from –20 dB to +20 dB. These are essentially
high-level signals. Most audio equipment outputs signals at line level. All MD4 inputs and out-
puts support line-level signals. Contrast with Low-Level Signal.