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03D—Owner’s Manual
MMC (MIDI Machine Control)
— A set of MIDI messages that can be used to con-
trol audio and video tape machines, disk recorders, and other studio equipment. Typi-
cal MMC commands include Stop, Play, Rewind, and Pause.
Modulation
—In general audio, using an LFO (low frequency oscillator) to control a
signal’s frequency (pitch) or amplitude (level). The LFO frequency is set using modu-
lation frequency parameters and the amount of LFO control is set using modulation
depth parameters. Delay time and auto-pan speed parameters are also modulated.
MSB (Most Significant Byte)
—
The byte of a digital word that represents the high-
est value. Contrast with LSB
MTC (MIDI Timecode)
—An addition to the MIDI Standard that allows audio
equipment to be synchronized. MIDI Timecode contains clock and position informa-
tion.
Noise gate
—An electronic switch that opens when a trigger signal falls below a set
threshold point and closes when the trigger signal exceeds that same threshold point.
Used to shut off unwanted hiss and noise.
Nominal level
—See Operating Level.
Nyquist theorem
—The Nyquist theorem states that the sampling rate of a digital
audio system must be at least twice that of the highest audio frequency, otherwise wave-
form distortion called aliasing will occur. See also Aliasing.
OMNI
—The MIDI mode in which a device responds to MIDI data on all 16 channels.
Operating level
—This is the signal level at which a piece of audio equipment is
designed to operate. The two most common operating levels are –10 dBV (316 mV),
which is used by semiprofessional equipment, and +4 dBu (1.23 V), which is used by
professional equipment.
Oversampling
—Sampling an audio signal at a rate higher than the normal sampling
rate. The net effect is that noise caused by quantization errors is reduced.
PAM (Pulse Amplitude Modulation)
—In the first part of the A/D conversion,
pulses occurring at the sampling rate are modulated by an analog audio signal. See also
PCM.
PC
—Originally, the abbreviation for personal computer. Although today it’s used as
the generic name for an IBM compatible personal computer, usually running a version
of the Microsoft Windows operating system.
PCM (Pulse Code Modulation)
—In the second part of the A/D conversion, the
pulses derived using PAM are converted into binary data words using PCM. See also
PAM.
Peaking
—A type of EQ circuit used to cut and boost a band of frequencies. It pro-
duces a mountain-peak type curve. The width of the frequency band is controlled by
the Q parameter. Midband EQ is usually of the peaking type. Compare with Shelving.
PFL (Pre Fader Listen)
—A mixer function that allows monitoring of a signal before
it’s fed to the channel fader. Contrast with AFL.
Pink noise
—A type of random noise that contains an equal amount of energy per
octave. The bands 100–200, 800–1600, and 3000–6000 all contain the same amount of
energy. White noise, on the other hand, has an equal amount of energy per frequency
band. That is, 100–200, 800–900, and 3000–3100.
Post fader
—A point in the signal path after a fader. Aux send controls are often con-
figured as post-fader sends, which means the signal for the aux send is sourced after the
channel fader. The advantage of this is that the aux send signal can be controlled at the
same time as the main channel signal using the channel fader. Post-fader aux sends are
often used to feed effects processors. See also AFL.
