Файл: Sound Tech Terms Dictionary.pdf

M

microphone:  An electroacoustic device which delivers an electrical signal when actuated by a

sound.  A microphone consists of an acoustic system that supplies mechanical (acoustic) en-
ergy to a transducer, which converts the energy into electrical energy.  Microphones are classi-
fied by their acoustical parameters, by their method of transduction, and by their directional
characteristics.  See capsule, cardioid, supercardioid, hypercardioid, ribbon microphone, moving coil
microphone, condenser microphone, dynamic microphone, boundary microphone, Soundfield micro-
phone, Lavalier microphone, contact microphone, and omnidirectional microphone.

Attribute

Construction

Moving Coil

Ribbon

Condenser

Normal Polar Response

cardioid

figure-8

cardioid/switchable

Robustness

high

low-average

average

Cost

low

average

high

Examples

Shure SM58

Beyer M88

AKG C451

Electrovoice RE20

Neumann U87

Transient/HF Response

good

very good

excellent

Diaphragm Weight

high

low

average

Output

average

low

high

Sensitivity/Efficiency

average

low

high

Application

general purpose

strings, vocal

acoustic instruments,

vocal, brass

overheads

piano, vocals,

combos, kick drums

snare, hi-hats

Side Effects

average sound

handling and rumble

crackles when wet

slightly fragile

needs phantom power

Sound Characteristic

solid

smooth

crisp

microphone preamplifier:  See preamplifier.

microphonic noise:  Noise generated within an audio cable, caused by changes in capacitance

between the inner conductors in the cable  and/or its shield.  Microphonic noise can result
from unstable dielectric (insulating) material that allows the conductors and/or shield to
move in relation to one another.

microtuning:  A system that uses different intervals  between notes in a scale.  A number of

microtuning systems attempt to reduce beat frequencies introduced by the simultaneous
playing of the notes of a chord.  Some systems use different numbers of notes in an octave
(up to 53).  It is necessary to decide on the key before a microtuning system can be selected.
Instruments which support microtuning are called microtonal.  See equal temperament, just in-
tonation, temperament.

middle-eight:  See bridge(4).

M

MIDI:  Musical Instrument Digital Interface.  MIDI is a specification for the types of control

signals that can be sent from one electronic music device to another.  MIDI is a serial protocol,
with a word length of 30 bits and a transmission speed of 32kbps.  MIDI messages are either
channel messages or system messages, the first of which describes the actual musical content of
the sound, and all other synthesizer actions affecting that sound are controlled by the latter.

MIDI analyzer:  A device that gives a visual display of MIDI activity when inserted between

two pieces of MIDI equipment.

MIDI Bank Change:  A type of MIDI controller message which is used to select alternate

banks of MIDI patches where access to more than 128 patches is required.

MIDI choke:  See MIDI delay(2).

MIDI Clock:  A timing reference signal sent over a MIDI cable a the rate of 24ppq; a System

Real-Time message used to communicate timing information among instruments in a MIDI
system.  Also known as MIDI Sync.  See also MTC.

M

MIDI Controllers:  (1) Devices which generate MIDI messages and which typically resemble

musical instruments such as keyboards, guitars, drums, etc.  Although originally conceived
with a keyboard paradigm, MIDI controllers are now available as guitars, wind valves, drum
kits, xylophone, piano, accordion, the violin family, as well as keyboards of all types.  (2)
MIDI Controller messages.  These are a type of Channel Voice message designed for adjust-
ing individual controls, such as pan position or channel volume, on equipment in the MIDI
network.  While not a part of the MIDI  specification, certain conventions exist.  The table
below gives some of the more common controller numbers.  See also controller change, con-
tinuous controllers, switched controllers.

Controller messages can be switched, i.e., their value is either On or Off, or they can be con-
tinuous.  Controller messages 0-31 take one additional data byte and can therefore carry val-
ues in the range 0-127.  However, these can be paired with controllers 32-63 to provide two
bytes of resolution, e.g., Controller 4 is paired with Controller 36.  When this is done, the con-
troller in the range 0-31 takes the MSB and its pair in the range 32-63 takes the LSB, for a
range of 16,384 possible values.  Most continuous controllers carry values ranging upward
from 0, although physical controllers that center around zero, such as balance, pan, and
pitch-bend may be implemented so that their associated controller message carries values
centered on the midpoint.

0

bank select MSB

1

modulation wheel

2

breath controller

4

foot controller

5

portamento time

6

data entry MSB

7

channel volume

8

balance

10

pan

11

expression controller

12

effects control 1

13

effects control 2

16-19

general purpose 1-4

32-63

LSB for controllers 0-31

64

sustain pedal

65

portamento

66

sostenuto

67

soft pedal

68

legato footswitch

69

hold 2












































Continuous

Controllers

Switched

Controllers

Controller #

Function

70-79

sound controllers 1-10*

synths

effects units

70

sound variation

exciter

71

harmonic content 

compressor

72

release time

distortion

73

attack time

equalizer

74

brightness

expander

80-83

general purpose 5-8

91-95

effects depth 1-5**

96-101 data controllers
120

all sounds off

121

reset all controllers

122

local control

123

all notes off

124

omni mode off

126

omni mode on

126

mono mode on (poly mode off)

127

poly mode on (mono mode off)



















Channel Mode

Messages

Controller #

Function

MIDI Controllers

*  Manufacturers may implement these as desired.  The first 5 default as indicated.
** Originally assigned to specific effects such as chorus, phaser, tremolo, etc.

M

MIDI Delay:  (1) A facility provided on some sequencers to allow a track to be fractionally

delayed or advanced relative to others.  Particularly useful for synthesizer voices which
speak late, or to give a part a sense of urgency by being played very slightly ahead of the
beat.  Also called MIDI offset.  (2) Noticeable delay in the transmission caused by MIDI
Choke.  This usually happens when too many MIDI devices try to send bulk dumps or un-
thinned continuous controller data over the same MIDI port.

MIDI Echo:  A feature that routes MIDI messages appearing at a device’s MIDI In port

through its processor, unaltered, to the MIDI Out port.  This allows control of a MIDI sound
module simultaneously from a sequencer and a keyboard.  MIDI Echo differs from MIDI
Thru in that there is a direct, hard-wired connection between the MIDI In and Thru jacks, so
the datastream doesn’t pass through the device’s processor.

MIDI filter:  See filter(2).

MIDI interface/adapter:  A device that converts data from a MIDI device to a format that a

computer can recognize.

MIDI loop:  A (mistakenly) hard-wired loop.  See note-doubling.

MIDI Machine Control (MMC):  A protocol for using MIDI commands, usually from a se-

quencer, to control the transport functions (stop/play/record/locate/rewind/fast forward)
of a tape recorder or other mechanical device.  MMC is intended to link MIDI equipment
with more traditional equipment such as audio and video tape machines and multimedia
computer devices.

MIDI Mapper:  An applet that automatically maps channel, program change, and note num-

ber data.  For example, a map could cause all notes coming in on MIDI channel 3 to go out on
MIDI channel 7.

MIDI Merge:  The process of combining MIDI messages transmitted from two or more MIDI

devices into one coherent MIDI data stream so that the messages appear to have been gener-
ated by only one device.  This is not just connecting MIDI cables as MIDI messages are struc-
tured and this structure needs to be preserved.  For example, if two Note On messages arrive
simultaneously at the two inputs, the merge device will have to store one of them in a buffer
until the first is sent.  Because MIDI messages are variable in length, and because real-time
massages have to take a priority, the merge device must be able to identify and distinguish
between different data types.  This generally requires a separate microprocessor, making a
MIDI merge unit more expensive than a MIDI Thru device.

M

MIDI message:  A full instruction consisting of at least one status byte and frequently with

one or more data bytes, which causes a MIDI device to perform one of the functions defined
in the MIDI specification.  See also entries for each message
type.

System Messages

(apply to the whole system)

Channel Voice

(Note On)

(Program Change)

Channel Mode

(Local On)

(Reception Mode)

System Common

(Song Position)
(Tune Request)

System Real-Time

(Timing Clock)

(System Reset)

System Exclusive

(Data for specific

items of equipment)

Channel Messages

(apply to an individual channel)

        

                  

MIDI Messages

(Message examples)

                          

MIDI module:  A device for generating sound which does not have an integral keyboard.

MIDI network:  A collection of MIDI devices connected together in such a way that MIDI

messages can pass between them.  The most common network is a daisy chain (each device
connected to the previous device, i.e., in a linear arrangement) or in a star topology, where
each device is connected to a central point, such as a multi-port MIDI interface.

MIDI Mode:  Also called channel mode or reception mode.  A setting that determines how a par-

ticular MIDI device or instrument reacts to transmitted voice and channel data.  Four modes
are created  by different combinations of the messages Omni On/Off (defining the ability to
react to data on all MIDI channels) and Poly/Mono (playing notes polyphonically or mono-
phonically):

Omni On/Poly

Mode 1

The receiving instrument reacts to data on all MIDI channels
(Omni) while playing polyphonically.

Omni On/Mono

Mode 2

Similar to Mode 1, but the instrument plays monophonically (rarely
used).

Omni Off/Poly

Mode 3 “Multi”

Each synth (or multitimbral part) plays polyphonically on its own
MIDI channel.

Omni Off/Mono

Mode 4 “Mono”

Used for MIDI guitar as it allows each string to play monophoni-
cally on its own MIDI channel.

MIDI Note Number:  The decimal number, from 0-128, which represents the equal tempera-

ment scale of about eight octaves, where 60 represents Middle-C, having a frequency of
261.63Hz.  The MIDI note number 36, for example, corresponds to the 4

th

 key on a piano, re-

ferred to as C1, with a frequency of 32.7Hz.  Middle-C is sometimes called C3 or C4, de-
pending on the author.  Commonly, modern instruments are tuned to A440, that is A3/A4,
MIDI note number 69.

MIDI Offset:  See MIDI Delay.

MIDI Out/Thru:  A MIDI output port that can be configured either to transmit MIDI mes-

sages generated within the unit (Out) or to retransmit messages received at the MIDI In
(Thru).  See MIDI echo.