Glossary - Akai MPC X User Manual

Glossary

This glossary briefly defines and explains many of the technical terms used throughout this manual.
Aftertouch The majority of contemporary keyboards are capable of generating aftertouch messages. On this
type of keyboard, when you press harder on a key you are already holding down, a MIDI aftertouch
message is generated. This feature makes sounds even more expressive (e.g., through vibrato).
Aliasing Aliasing is an audible side effect arising in digital systems as soon as a signal contains harmonics
higher than half the sampling frequency.
Amount Describes to which extent a modulation source influences a given parameter.
Amplifier An amplifier is a component that influences the volume level of a sound via a control signal. It
can be modulated by a control signal (e.g., generated by an
Attack envelope
An
envelope from its starting point to the point where it reaches its highest value). The attack phase
is initiated immediately after a trigger signal is received (e.g., after you play a note on a trigger
pad or a keyboard).
Bit Rate Bit rate (also known as word length), is the number of bits used to store the level information of
each single sample slice within a whole sample. The higher the bit rate, the more precise the
information about a sample (i.e., its dynamics' resolution). Normal audio CDs are 16-bit. The
MPC hardware supports full 24-bit resolution.
Bounce When you "bounce" a sequence, track, or program, you are rendering that part of your project as
an audio file (as opposed to a MIDI file). The MPC hardware lets you bounce sequences, tracks,
or programs as samples (saved to your project's sample pool) or as full audio tracks (saved to
your project's sample pool and added directly to the current sequence).
Bouncing a track will render that track after it is sent through its program. Bouncing a program
will render all tracks that use that program after they are sent through it. Bouncing a sequence
will render all tracks in that sequence after they are sent through their respective programs.
Clipping Clipping is a sort of distortion that occurs when a signal exceeds the maximum value that can be
handled by a signal processing system it is fed into. The curve of a clipped signal is dependent
on the system where the clipping occurs. In the analog domain, clipping effectively limits the
signal to a given maximum level. In the digital domain, clipping is similar to a numerical overflow,
resulting in negative polarity of the signal's portions exceeding the maximum level.
Control Change MIDI messages enable you to manipulate the behavior of a sound generator to a significant
degree. This message essentially consists of two components:
(Controllers)
•
•
Controllers can be used for effects such as slowly swelling vibrato, changing the stereo panning
position and influencing filter frequency.
Cutoff The cutoff frequency is a significant factor for a filter. A low-pass filter for example dampens the
portion of the signal that lies above this frequency. Frequencies below this value are allowed to
pass through without being processed.
parameter. This term describes the ascent rate of a time-relevant process (e.g., an
The controller number, which defines the parameter to be influenced. It can range from 0
to 127.
The controller value, which determines the extent of the modification.
envelope or an LFO).
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