A mixing console or mixing desk is an electronic device for
mixing audio signals, used in
sound recording and reproduction
Sound recording and reproduction is the electrical, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording te ...
and
sound reinforcement system
A sound reinforcement system is the combination of microphones, signal processors, amplifiers, and loudspeakers in enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may also distribute those sounds ...
s. Inputs to the console include
microphone
A microphone, colloquially called a mic or mike (), is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public ...
s, signals from electric or electronic instruments, or recorded sounds. Mixers may control analog or
digital signal
A digital signal is a signal that represents data as a sequence of discrete values; at any given time it can only take on, at most, one of a finite number of values. This contrasts with an analog signal, which represents continuous values; at ...
s. The modified signals are
summed to produce the combined output signals, which can then be broadcast, amplified through a sound reinforcement system or recorded.
Mixing consoles are used for applications including
recording studio
A recording studio is a specialized facility for sound recording, mixing, and audio production of instrumental or vocal musical performances, spoken words, and other sounds. They range in size from a small in-home project studio large enoug ...
s,
public address system
A public address system (or PA system) is an electronic system comprising microphones, amplifiers, loudspeakers, and related equipment. It increases the apparent volume (loudness) of a human voice, musical instrument, or other acoustic sound sou ...
s, sound reinforcement systems,
nightclub
A nightclub (music club, discothèque, disco club, or simply club) is an entertainment venue during nighttime comprising a dance floor, lightshow, and a stage for live music or a disc jockey (DJ) who plays recorded music.
Nightclubs gener ...
s,
broadcasting
Broadcasting is the distribution (business), distribution of sound, audio or video content to a dispersed audience via any electronic medium (communication), mass communications medium, but typically one using the electromagnetic spectrum (radio ...
, and
post-production
Post-production is part of the process of filmmaking, video production, audio production, and photography. Post-production includes all stages of production occurring after principal photography or recording individual program segments.
The ...
. A typical, simple application combines signals from microphones on stage into an amplifier that drives one set of
loudspeaker
A loudspeaker (commonly referred to as a speaker or speaker driver) is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound. A ''speaker system'', also often simply referred to as a "speaker" or " ...
s for the audience. A
DJ mixer
A DJ mixer is a type of audio mixing console used by disc jockeys (DJs) to control and manipulate multiple audio signals. Some DJs use the mixer to make seamless transitions from one song to another when they are playing records at a dance clu ...
may have only two channels, for mixing two
record players
A phonograph, in its later forms also called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910) or since the 1940s called a record player, or more recently a turntable, is a device for the mechanical and analogu ...
. A
coffeehouse
A coffeehouse, coffee shop, or café is an establishment that primarily serves coffee of various types, notably espresso, latte, and cappuccino. Some coffeehouses may serve cold drinks, such as iced coffee and iced tea, as well as other non-ca ...
's tiny stage might only have a six-channel mixer, enough for two singer-guitarists and a percussionist. A nightclub stage's mixer for
rock music
Rock music is a broad genre of popular music that originated as " rock and roll" in the United States in the late 1940s and early 1950s, developing into a range of different styles in the mid-1960s and later, particularly in the United States an ...
shows may have 24 channels for mixing the signals from a
rhythm section
A rhythm section is a group of musicians within a music ensemble or band that provides the underlying rhythm, harmony and pulse of the accompaniment, providing a rhythmic and harmonic reference and "beat" for the rest of the band.
The rhythm sec ...
,
lead guitar
Lead guitar (also known as solo guitar) is a musical part for a guitar in which the guitarist plays melody lines, instrumental fill passages, guitar solos, and occasionally, some riffs and chords within a song structure. The lead is the featur ...
and several vocalists. A mixing console in a professional recording studio may have as many as 96 channels.
In practice, mixers do more than simply mix signals. They can provide
phantom power
Phantom power, in the context of professional audio equipment, is DC electric power transmitted through microphone cables to operate microphones that contain active electronic circuitry.
It is best known as a convenient power source for con ...
for
condenser microphone
A microphone, colloquially called a mic or mike (), is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public ...
s;
pan control, which changes a sound's apparent position in the stereo soundfield;
filtering
Filter, filtering or filters may refer to:
Science and technology
Computing
* Filter (higher-order function), in functional programming
* Filter (software), a computer program to process a data stream
* Filter (video), a software component tha ...
and
equalization, which enables sound engineers to boost or cut selected frequencies to improve the sound;
dynamic range compression
Dynamic range compression (DRC) or simply compression is an audio signal processing operation that reduces the volume of loud sounds or amplifies quiet sounds, thus reducing or ''compressing'' an audio signal's dynamic range. Compression is ...
, which allows engineers to increase the overall gain of the system or channel without exceeding the dynamic limits of the system; routing facilities, to send the signal from the mixer to another device, such as a
sound recording
Sound recording and reproduction is the electrical, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording te ...
system or a control room; and monitoring facilities, whereby one of a number of sources can be routed to loudspeakers or headphones for listening, often without affecting the mixer's main output. Some mixers have onboard electronic effects, such as reverb. Some mixers intended for small venue live performance applications may include an integrated
power amplifier
An audio power amplifier (or power amp) is an electronic amplifier that amplifies low-power electronic audio signals, such as the signal from a radio receiver or an electric guitar pickup, to a level that is high enough for driving loudspea ...
.
Terminology
A mixing console is also known as an audio mixer, audio console, mixing desk, sound mixer, soundboard, or simply as a board or mixer.
Structure
![Yamaha MC2403 audio mixing console (1992)](https://upload.wikimedia.org/wikipedia/commons/4/47/Yamaha_MC2403_audio_mixing_console_%281992%29.jpg)
An analog mixing board is divided into functional sections. Some of the more important functional sections are subdivided into subsections.
Channel input strip
The channel input strips are usually a bank of identical
monaural
Monaural or monophonic sound reproduction (often shortened to mono) is sound intended to be heard as if it were emanating from one position. This contrasts with stereophonic sound or ''stereo'', which uses two separate audio channels to reproduc ...
or
stereo
Stereophonic sound, or more commonly stereo, is a method of sound reproduction that recreates a multi-directional, 3-dimensional audible perspective. This is usually achieved by using two independent audio channels through a configuration ...
input channels arranged in columns. Typically, each channel's column contains a number of rotary
potentiometer
A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. If only two terminals are used, one end and the wiper, it acts as a variable resistor or rheostat.
The measuring instrume ...
knobs, buttons, and
faders for controlling the
gain
Gain or GAIN may refer to:
Science and technology
* Gain (electronics), an electronics and signal processing term
* Antenna gain
* Gain (laser), the amplification involved in laser emission
* Gain (projection screens)
* Information gain in de ...
of the input
preamplifier
A preamplifier, also known as a preamp, is an electronic amplifier that converts a weak electrical signal into an output signal strong enough to be noise-tolerant and strong enough for further processing, or for sending to a power amplifier an ...
, adjusting the
equalization of the signal on each channel, controlling routing of the input signal to other functional sections, and adjusting the channel's contribution to the overall mix being produced.
The types of inputs that can be plugged into a mixer depend on the intended purpose of the mixer. A mixer intended for a live venue or a recording studio typically has a range of input jacks, such as
XLR connector
The XLR connector is a type of electrical connector primarily used in professional audio, video, and stage lighting equipment. XLR connectors are cylindical in design, and have three to seven connector pins, and are often employed for analog b ...
s for microphones and the outputs from
DI box
A DI unit (direct input or direct inject) is an electronic device typically used in recording studios and in sound reinforcement systems to connect a high-output impedance, line level, unbalanced output signal to a low-impedance, microphone level ...
es, and
1/4" jacks for
line level
Line level is the specified strength of an audio signal used to transmit analog audio between components such as CD and DVD players, television sets, audio amplifiers, and mixing consoles.
Line level sits between other levels of audio signals. ...
sources. A
DJ mixer
A DJ mixer is a type of audio mixing console used by disc jockeys (DJs) to control and manipulate multiple audio signals. Some DJs use the mixer to make seamless transitions from one song to another when they are playing records at a dance clu ...
typically has
RCA connector
The RCA connector is a type of electrical connector commonly used to carry audio and video signals. The name ''RCA'' derives from the company Radio Corporation of America, which introduced the design in the 1930s. The connectors male plug and ...
inputs for pre-recorded music being played back on
turntable
A phonograph, in its later forms also called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910) or since the 1940s called a record player, or more recently a turntable, is a device for the mechanical and analogu ...
s or
CD player
A CD player is an electronic device that plays audio compact discs, which are a digital optical disc data storage format. CD players were first sold to consumers in 1982. CDs typically contain recordings of audio material such as music or aud ...
s, and a single mic input.
Depending on the mixer, a channel may have buttons which enable the audio engineer to reroute the signal to a different output for monitoring purposes, turn on an
attenuator pad (often reducing the signal by 15 or 20 dB to prevent
audio clipping), or activate other features, such as a
high-pass filter
A high-pass filter (HPF) is an electronic filter that passes signals with a frequency higher than a certain cutoff frequency and attenuates signals with frequencies lower than the cutoff frequency. The amount of attenuation for each frequency d ...
. Some higher-priced mixers have a
parametric equalizer
Equalization, or simply EQ, in sound recording and reproduction is the process of adjusting the volume of different frequency bands within an audio signal. The circuit or equipment used to achieve this is called an equalizer.
Most hi-fi eq ...
or a semi-parametric equalizer for one or more of the equalizer frequency bands, often the
middle range
The Xueshan Range is a mountain range in northern Taiwan. It faces the Chungyang Range on the southeast. The tallest peak of Xueshan Range is Xueshan ("Snowy Mountain"), which has a height of . Shei-Pa National Park is located around the peaks o ...
.
The channel strips are typically numbered so that the audio engineer can identify the different channels. For each channel input, a mixer provides one or more input jacks. On mid- to- large-sized live venue and sound recording consoles, these input jacks are numbered as well and consolidated in a
patch bay
A patch panel is a device or unit featuring a number of jacks, usually of the same or similar type, for the use of connecting and routing circuits for monitoring, interconnecting, and testing circuits in a convenient, flexible manner. Patch ...
. On smaller mixers, the input jacks may be mounted on the top panel of the mixer to facilitate the connection and disconnection of inputs during the use of the mixer.
The input strip is usually separated into sections:
*
Input jacks
*
Microphone preamplifier
The term microphone preamplifier can either refer to the electronic circuitry within a microphone, or to a separate device or circuit that the microphone is connected to. In either instance, the purpose of the microphone preamplifier is the same.
...
s
*
Equalization
* Dynamics processing (e.g.
dynamic range compression
Dynamic range compression (DRC) or simply compression is an audio signal processing operation that reduces the volume of loud sounds or amplifies quiet sounds, thus reducing or ''compressing'' an audio signal's dynamic range. Compression is ...
,
gating), if supported
* Routing, including direct outs,
auxiliary-sends,
panning control, and subgroup assignments
* Level-control
faders (on small mixers, these may be rotary knobs to save space and cost)
On many consoles, these sections are color-coded for quick identification by the operator. Each signal (e.g., a singer's vocal mic, the signal from an electric bass amp's
DI box
A DI unit (direct input or direct inject) is an electronic device typically used in recording studios and in sound reinforcement systems to connect a high-output impedance, line level, unbalanced output signal to a low-impedance, microphone level ...
, etc.) that is plugged into the mixer has its own ''channel''. Depending on the specific mixer, each channel is stereo or monaural. On most mixers, each channel has an
XLR input, and many have
RCA
The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Comp ...
or quarter-inch
TRS phone connector line inputs. The smallest, least expensive mixers may only have one XLR input with the other inputs being line inputs. These can be used by a singer-guitarist or other small acts.
Basic input controls
The first knob at the top of an input strip is typically a ''trim'' or ''
gain
Gain or GAIN may refer to:
Science and technology
* Gain (electronics), an electronics and signal processing term
* Antenna gain
* Gain (laser), the amplification involved in laser emission
* Gain (projection screens)
* Information gain in de ...
'' control. The input/preamp conditions the signal from the external device and this controls the amount of amplification or
attenuation
In physics, attenuation (in some contexts, extinction) is the gradual loss of flux intensity through a medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and sound at variable att ...
that is applied to the input signal to bring it to a
nominal level
Nominal level is the operating level at which an electronic signal processing device is designed to operate. The electronic circuits that make up such equipment are limited in the maximum signal they can handle and the low-level internally genera ...
for processing. Due to the high gains involved (around +50
dB, for a microphone), this stage is where most noise and interference is picked up.
Balanced
In telecommunications and professional audio, a balanced line or balanced signal pair is a circuit consisting of two conductors of the same type, both of which have equal impedances along their lengths and equal impedances to ground and to other ...
inputs and connectors, such as XLR or phone connectors that have been specifically wired as balanced lines, reduce interference problems.
A microphone plugged directly into a
power amplifier
An audio power amplifier (or power amp) is an electronic amplifier that amplifies low-power electronic audio signals, such as the signal from a radio receiver or an electric guitar pickup, to a level that is high enough for driving loudspea ...
would not produce an adequate signal level to drive loudspeakers, because the microphone's signal is too weak; the microphone signal needs a
preamplifier
A preamplifier, also known as a preamp, is an electronic amplifier that converts a weak electrical signal into an output signal strong enough to be noise-tolerant and strong enough for further processing, or for sending to a power amplifier an ...
to strengthen the signal so that it is strong enough for the power amplifier. For some very strong
line level
Line level is the specified strength of an audio signal used to transmit analog audio between components such as CD and DVD players, television sets, audio amplifiers, and mixing consoles.
Line level sits between other levels of audio signals. ...
signals, the signal that is plugged into the mixer may be too strong, and cause
audio clipping. For signals that are too strong, a 15 dB or 20 dB
pad can be used to attenuate the signal. Both preamplifiers and pads, and the controls associated with them, are available in the input section of most mixing consoles.
Audio engineers typically aim at achieving a good ''gain structure'' for each channel. To obtain a good gain structure, engineers usually raise the gain as high as they can before
audio clipping results; this helps to provide the best
signal-to-noise ratio
Signal-to-noise ratio (SNR or S/N) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to the noise power, often expressed in deci ...
.
A mixing console may provide
insert Insert may refer to:
*Insert (advertising)
*Insert (composites)
*Insert (effects processing)
*Insert (filmmaking)
*Insert key on a computer keyboard, used to switch between insert mode and overtype mode
*Insert (molecular biology)
*Insert (SQL)
*Fi ...
points after the input gain stage. These provide a send and return connection for external processors that only affect an individual channel's signal. Effects that operate on multiple channels connect to auxiliary sends (below).
Auxiliary send routing
The ''auxiliary send'' routes a split of the incoming signal to an auxiliary bus, which can then be routed to external devices. ''Auxiliary sends'' can either be pre-fader or post-fader, in that the level of a pre-fader send is set by the ''auxiliary send'' control, whereas post-fade sends depend on the position of the channel fader as well. ''Auxiliary sends'' can send the signal to an external processor such as a reverb, with the return signal routed through another channel or designated auxiliary return. Post-fader sends are normally used in this case. Pre-fade ''auxiliary sends'' can provide a monitor mix to musicians on stage (which they hear through
monitor speakers pointing at the performers or in-ear monitors); this mix is thus independent of the main mix produced by the faders.
![School - Board 2](https://upload.wikimedia.org/wikipedia/commons/5/53/School_-_Board_2.jpg)
Most live radio broadcasting sound boards send audio through ''program'' channels. Most boards have 3-4 program channels, though some have more options. When a given channel button is selected, the audio will be sent to that device or transmitter. Program 1 is typically the on-air live feed, or what those listening to the broadcast will hear. Other program channels may feed one or more computers used for editing or sound playback. Another program channel may be used to send audio to the talent's headset if they are broadcasting from a remote area.
Channel equalization
Further channel controls affect the equalization of the signal by separately attenuating or boosting a range of
frequencies
Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...
. The smallest, least expensive mixers may only have bass and treble controls. Most mid-range and higher-priced mixers have bass, midrange, and treble, or even additional mid-range controls (e.g., low-mid and high-mid). Many high-end mixing consoles have
parametric equalization
Equalization, or simply EQ, in sound recording and reproduction is the process of adjusting the volume of different frequency bands within an audio signal. The circuit or equipment used to achieve this is called an equalizer.
Most hi-fi eq ...
on each channel. Some mixers have a general equalization control (either
graphic
Graphics () are visual images or designs on some surface, such as a wall, canvas, screen, paper, or stone, to inform, illustrate, or entertain. In contemporary usage, it includes a pictorial representation of data, as in design and manufacture, ...
or parametric) at the output, for controlling the tone of the overall mix.
Cue system
The
cue system allows the operator to listen to one or more selected signals without affecting the console's main outputs. A sound engineer can use the cue feature to, for instance, get a sound recording they wish to play soon cued up to the start point of a song, without the listeners hearing these actions. The signal from the cue system is fed to the console's
headphone amp and may also be available as a line-level output that is intended to drive a monitor speaker system. The terms AFL (after-fader listen) and PFL (pre-fader listen) are used to describe respectively whether or not the level of the cue signal for an input is controlled by the corresponding fader. Consoles with a cue feature have a dedicated button on each channel, typically labeled ''Cue'', ''AFL'', ''PFL'', ''Solo'', or ''Listen''. When cue is enabled on multiple channels, a mix of these signals is heard through the cue system.
Solo in place (SIP) is a related feature on advanced consoles. It typically is controlled by the cue button, but unlike cue, SIP affects the output mix; It mutes everything except the channel or channels being soloed. SIP is useful for setup of a mixing board and troubleshooting, in that it allows the operator to quickly mute everything but the signal being adjusted. For example, if an audio engineer is having problems with clipping on an input, they may use SIP to solely hear that channel, so that the problem can be diagnosed and addressed. SIP is potentially disastrous if engaged accidentally during a performance, as it will mute all the channels except one, so most consoles require the operator to take very deliberate actions to engage SIP.
Busses and submix
Each channel on a mixer has a volume control (''
fader'') that allows adjustment of the level of that channel. These are usually sliders near the front of the mixing board, although some smaller mixers use rotary controls to save space. The signals are summed to create the main ''mix'', or combined on a ''
bus
A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a road vehicle that carries significantly more passengers than an average car or van. It is most commonly used in public transport, but is also in use for cha ...
'' as a submix, a group of channels that are then added as a whole to the final mix. For instance, many drum mics could be grouped into a bus, and then the proportion of drums in the final mix can be controlled with one bus fader. A bus can often be processed just like an individual input channel, allowing the engineer to process a whole group of signals at once. Once again using the drum kit example, the use of bus-processing can enable the sound engineer to run all of the drum kit through an audio compressor effect to reduce unwanted signal peaks, rather than having to route all of the 10 or more mic signals on the drum kit individually. There may also be insert points for a certain bus, or even the entire mix.
VCA groups
Some higher-end consoles use
voltage-controlled amplifier
A variable-gain (VGA) or voltage-controlled amplifier (VCA) is an electronic amplifier that varies its gain depending on a control voltage (often abbreviated CV).
VCAs have many applications, including audio level compression, synthesizers and ...
(VCA) VCAs function somewhat like a submix but let the operator control the level of multiple input channels with a single fader. Unlike subgroups, no sub-mix is created. The audio signals from the assigned channels remain routed independently of VCA assignments. Since no sub-mix is created, it is not possible to insert processing such as compressors into a VCA group. In addition, on most VCA-equipped consoles, post-fader auxiliary send levels are affected by the VCA master. This is usually desirable, as post-fader auxiliary sends are commonly used for effects such as reverb, and sends to these effects should track changes in the channel signal level. When implemented on a digital console the same functionality may be referred to as a DCA or control group (CG), depending on the brand of mixer.
Master output controls
The master control section is used to adjust the levels of the overall output of the mixer. The master control section on a large live venue or sound recording mixer typically has sub-group faders, master faders, master auxiliary mixing bus level controls and auxiliary return level controls. On most mixers, the master control is a fader. However, on some small mixers, rotary knobs are used instead to save space (and cost).
In a typical live sound mixing context, with a band playing at a venue, consisting of a rhythm section, solo instrumentalists and singers, the master control section allows the audio engineer to control the volume of the entire group with just one fader (for monaural mixers) or a pair of left and right faders (for stereo mixers).
Subgroup and main output fader controls are often found together on the right hand side of the mixer or, on larger consoles, in a center section flanked by banks of input channels. Matrix routing is often contained in this master section, as are headphone and local loudspeaker monitoring controls. Talkback controls allow conversation with the artist through their
monitors
Monitor or monitor may refer to:
Places
* Monitor, Alberta
* Monitor, Indiana, town in the United States
* Monitor, Kentucky
* Monitor, Oregon, unincorporated community in the United States
* Monitor, Washington
* Monitor, Logan County, West Vir ...
,
headphones
Headphones are a pair of small loudspeaker drivers worn on or around the head over a user's ears. They are electroacoustic transducers, which convert an electrical signal to a corresponding sound. Headphones let a single user listen to an au ...
or
in-ear monitor
In-ear monitors (IEMs) are devices used by musicians, audio engineers and audiophiles to listen to music or to hear a personal mix of vocals and stage instrumentation for live performance or recording studio mixing. They are also used by telev ...
. A test tone generator might be located in the master output section. Aux returns such as those signals returning from external processors are often in the master section.
Metering
There are usually one or more
VU or
peak meter
A peak meter is a type of measuring instrument that indicates visually the instantaneous level of an audio signal that is passing through it (a sound level meter). In sound reproduction, the meter, whether peak or not, is usually meant to corres ...
s to indicate the levels for each channel, for the master outputs and to indicate whether the console levels are
clipping
Clipping may refer to:
Words
* Clipping (morphology), the formation of a new word by shortening it, e.g. "ad" from "advertisement"
* Clipping (phonetics), shortening the articulation of a speech sound, usually a vowel
* Clipping (publications) ...
the signal. The sound engineer typically adjusts the gain of the input signals to get the strongest signal that can be obtained without causing clipping. Having the gain set as high as possible improves the
signal-to-noise ratio
Signal-to-noise ratio (SNR or S/N) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to the noise power, often expressed in deci ...
. Most mixers have at least one additional output besides the main mix. These are either individual bus outputs or ''auxiliary outputs'', used, for instance, to output a different mix to onstage monitors.
The meters may be above the input and master sections or they may be integrated into the input and master sections themselves. Meters may have needles or
LED
A light-emitting diode (LED) is a semiconductor Electronics, device that Light#Light sources, emits light when Electric current, current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy i ...
s. On meters using LEDs, there may be different colored LEDs to indicate when there is signal present in the channel's input; the audio level of the channel, typically by lighting up more LEDs; and clipping, which may be indicated using a different colored LED. In one popular color-coding system, green LEDs indicate signal presence and the audio level; one or more amber LEDs indicate that the channel is approaching clipping; and one or more red LEDs indicate clipping.
As the human ear experiences audio level in a
logarithm
In mathematics, the logarithm is the inverse function to exponentiation. That means the logarithm of a number to the base is the exponent to which must be raised, to produce . For example, since , the ''logarithm base'' 10 o ...
ic fashion, mixing console controls and displays are almost always labeled in
decibel
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a po ...
s, a logarithmic measurement system. Since the decibel represents a relative measurement, and not a unit itself, the meters must be referenced to a
nominal level
Nominal level is the operating level at which an electronic signal processing device is designed to operate. The electronic circuits that make up such equipment are limited in the maximum signal they can handle and the low-level internally genera ...
. Most
professional audio
Professional audio, abbreviated as pro audio, refers to both an activity and a category of high quality, studio-grade audio equipment. Typically it encompasses sound recording, sound reinforcement system setup and audio mixing, and studio mus ...
equipment is referenced to a nominal level of +4
dBu
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a Power, root-power, and field quantities, power or root-power quantity on a logarithmic scale. Two signals whose ...
, while semi-professional and domestic equipment is usually referenced to a nominal level of −10
dBV.
Hardware routing and patching
For convenience, some mixing consoles include inserts or a
patch bay
A patch panel is a device or unit featuring a number of jacks, usually of the same or similar type, for the use of connecting and routing circuits for monitoring, interconnecting, and testing circuits in a convenient, flexible manner. Patch ...
or patch panel. Patch bays are more common in recording mixers than live sound mixers. In live sound, the cables from the onstage microphones and instrument outputs are not typically plugged directly into the mixer, because this would require a large number of individual cables to go from the stage to the mixer. Instead, the onstage mic and instrument cables are typically plugged into the stage box of a
snake
Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Ma ...
cable which runs from the stage to the mixer. The snake is then plugged into the mixer.
Other features
![SSL9000J in use](https://upload.wikimedia.org/wikipedia/commons/8/89/SSL9000J_in_use.JPG)
Most, but not all, audio mixers can
* use monaural signals to produce simulated stereo sound through
panning.
* provide
phantom power
Phantom power, in the context of professional audio equipment, is DC electric power transmitted through microphone cables to operate microphones that contain active electronic circuitry.
It is best known as a convenient power source for con ...
required by condenser microphones.
Some mixers can
* add onboard external
effect unit
An effects unit or effects pedal is an electronic device that alters the sound of a musical instrument or other audio source through audio signal processing.
Common effects include distortion/overdrive, often used with electric guitar in ele ...
s (reverb,
echo
In audio signal processing and acoustics, an echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The delay is directly proportional to the distance of the reflecting surface from the source and the list ...
, delay). Mixers with onboard digital effects typically offer a wide range of these effects.
* create an audible
test tone
A test card, also known as a test pattern or start-up/closedown test, is a television test signal, typically broadcast at times when the transmitter is active but no program is being broadcast (often at sign-on and sign-off).
Used since the ear ...
via an
oscillator
Oscillation is the repetitive or periodic variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states. Familiar examples of oscillation include a swinging pendulum ...
. The test tone can be used to troubleshoot issues before the band arrives and determine if channels are functioning properly.
* read and write
console automation
In music recording, mix automation allows the mixing console to remember the audio engineer's adjustment of faders during the post-production editing process. A timecode is necessary for the synchronization of automation. Modern mixing console ...
.
* be interfaced with computers or other recording equipment.
* control or be controlled by a
digital audio workstation
A digital audio workstation (DAW) is an electronic device or application software used for Sound recording and reproduction, recording, editing and producing audio files. DAWs come in a wide variety of configurations from a single software pro ...
via
MIDI
MIDI (; Musical Instrument Digital Interface) is a technical standard that describes a communications protocol, digital interface, and electrical connectors that connect a wide variety of electronic musical instruments, computers, and re ...
,
USB
Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad ...
or other communication interface.
* be powered by
batteries.
* provide amplifier power for external
passive speakers
Mirroring
Some mixing consoles, particularly those designed for broadcast and live sound, include facilities for ''mirroring'' two consoles, making both consoles exact copies of each other with the same inputs and outputs, the same settings, and the same audio mix. There are two primary reasons for doing this; one, in the event of a hardware failure, a second redundant console is already in place and can be switched to (an important feature for live broadcasts); second, it allows the operators to set up two identical mix positions, one at front of house — where the audio will be mixed during a performance — and the other at some other location within the theater (e.g., with the broadcasting equipment); this way, if the acoustics at front of house are unfavorable, a mix can be programmed at an acoustically better position in the room, and the presets (on the faders and knobs) can be accessed from the front of house console during the performance.
Digital versus analog
Digital mixing console
In professional audio, a digital mixing console (DMC) is a type of mixing console used to combine, route, and change the dynamics, equalization and other properties of multiple audio input signals, using digital signal processing rather than an ...
sales have increased dramatically since their introduction in the 1990s.
Yamaha Yamaha may refer to:
* Yamaha Corporation, a Japanese company with a wide range of products and services, established in 1887. The company is the largest shareholder of Yamaha Motor Company (below).
** Yamaha Music Foundation, an organization estab ...
sold more than 1000 PM5D mixers by July, 2005, and other manufacturers are seeing increasing sales of their digital products. Digital mixers are more versatile than analog ones and offer many new features, such as reconfiguration of all signal routing at the touch of a button. In addition, digital consoles often include processing capabilities such as
compression
Compression may refer to:
Physical science
*Compression (physics), size reduction due to forces
*Compression member, a structural element such as a column
*Compressibility, susceptibility to compression
* Gas compression
*Compression ratio, of a ...
,
gating,
reverb
Reverberation (also known as reverb), in acoustics, is a persistence of sound, after a sound is produced. Reverberation is created when a sound or signal is reflected causing numerous reflections to build up and then decay as the sound is abso ...
, automatic
feedback
Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to ''feed back'' into itself. The notion of cause-and-effect has to be handled ...
suppression and
delay
Delay (from Latin: dilatio) may refer to:
Arts, entertainment, and media
* ''Delay 1968'', a 1981 album by German experimental rock band Can
* ''The Delay'', a 2012 Uruguayan film
People
* B. H. DeLay (1891–1923), American aviator and acto ...
. Some products are expandable via third-party
audio plug-in
An audio plug-in, in computer software, is a plug-in that can add or enhance audio-related functionality in a computer program. Such functionality may include digital signal processing or sound synthesis. Audio plug-ins usually provide their o ...
s that add further reverb, compression, delay and tone-shaping tools. Several digital mixers include
spectrograph
An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify mate ...
and
real-time analyzer functions. A few incorporate loudspeaker management tools such as
crossover filtering and
limiting
In electronics, a limiter is a circuit that allows signals below a specified input power or level to pass unaffected while attenuating (lowering) the peaks of stronger signals that exceed this threshold. Limiting is a type of dynamic range comp ...
.
Digital signal processing
Digital signal processing (DSP) is the use of digital processing, such as by computers or more specialized digital signal processors, to perform a wide variety of signal processing operations. The digital signals processed in this manner are ...
can perform
automatic mixing for some simple applications, such as courtrooms, conferences and panel discussions.
Latency
Digital mixers have an unavoidable amount of
latency, ranging from less than 1
ms to as much as 10 ms, depending on the model of digital mixer and what functions are engaged. This small amount of latency is not a problem for loudspeakers aimed at the audience and not necessarily a problem for monitor wedges aimed at the artist, but can be disorienting and unpleasant for
in-ear monitors
In-ear monitors (IEMs) are devices used by musicians, audio engineers and audiophiles to listen to music or to hear a personal mix of vocals and stage instrumentation for live performance or recording studio mixing. They are also used by t ...
where the artist hears their voice acoustically in their head ''and'' electronically amplified in their ears but delayed by a couple of milliseconds.
[Whirlwind. ''Opening Pandora's Box? The "L" word - latency and digital audio systems''](_blank)
/ref>
Every analog to digital conversion and digital to analog conversion within a digital mixer introduces latency. Audio inserts to favorite external analog processors make for approximately double the usual latency. Further latency can be traced to format conversions such as from ADAT
Alesis Digital Audio Tape (ADAT) is a magnetic tape format used for the recording of eight digital audio tracks onto the same S-VHS tape used by consumer VCRs.
Although it is a tape-based format, the term ''ADAT'' now refers to its successo ...
to AES3
AES3 is a standard for the exchange of digital audio signals between professional audio devices. An AES3 signal can carry two channels of pulse-code-modulated digital audio over several transmission media including balanced lines, unbalanced l ...
and from normal digital signal processing steps.
Within a digital mixer, there can be differing amounts of latency, depending on the routing and on how much DSP is in use. Assigning a signal to two parallel paths with significantly different processing on each path can result in comb filter
In signal processing, a comb filter is a filter implemented by adding a delayed version of a signal to itself, causing constructive and destructive interference. The frequency response of a comb filter consists of a series of regularly spaced no ...
ing when recombined. Some digital mixers incorporate internal methods of latency correction so that such problems are avoided.
Ease of use
Analog consoles have a column of dedicated, physical knobs, buttons, and faders for each channel, which is logical and familiar to generations of audio engineers who have been trained on analog mixers. This takes more physical space but can accommodate rapid responses to changing performance conditions.
Most digital mixers use technology to reduce physical space requirements, entailing compromises in user interface such as a single shared channel adjustment area that is selectable for only one channel at a time. Additionally, most digital mixers have virtual pages or layers that change fader banks into separate controls for additional inputs or for adjusting equalization or aux send levels. This layering can be confusing for some operators. Many digital mixers allow internal reassignment of inputs so that convenient groupings of inputs appear near each other in the fader bank, a feature that can be disorienting for persons having to make a hardware patch change.
On the other hand, many digital mixers allow for extremely easy building of a mix from saved data. USB flash drive
A USB flash drive (also called a thumb drive) is a data storage device that includes flash memory with an integrated USB interface. It is typically removable, rewritable and much smaller than an optical disc. Most weigh less than . Since firs ...
s and other storage methods are employed to bring past performance data to a new venue in a highly portable manner. At the new venue, the traveling mix engineer simply plugs the collected data into the venue's digital mixer and quickly makes small adjustments to the local input and output patch layout, allowing for full show readiness in very short order. Some digital mixers allow offline editing of the mix, a feature that lets the traveling technician use a laptop to make anticipated changes to the show, shortening the time it takes to prepare the sound system for the artist.
Sound quality
Both digital and analog mixers rely on analog microphone preamplifier
A preamplifier, also known as a preamp, is an electronic amplifier that converts a weak electrical signal into an output signal strong enough to be noise-tolerant and strong enough for further processing, or for sending to a power amplifier an ...
s, a high-gain circuit that increases the low signal level from a microphone to a level that is better matched to the console's internal operating level.
In a digital mixer, the microphone preamplifier is followed by an analog-to-digital converter
In electronics, an analog-to-digital converter (ADC, A/D, or A-to-D) is a system that converts an analog signal, such as a sound picked up by a microphone or light entering a digital camera, into a digital signal. An ADC may also provide ...
. Ideally, this process is carefully engineered to deal gracefully with overloading and clipping
Clipping may refer to:
Words
* Clipping (morphology), the formation of a new word by shortening it, e.g. "ad" from "advertisement"
* Clipping (phonetics), shortening the articulation of a speech sound, usually a vowel
* Clipping (publications) ...
while delivering an accurate digital stream. Overloading during further processing and mixing of digital streams can be avoided by using floating-point arithmetic
In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. For example, 12.345 can be ...
. Intermediate processing in older systems using fixed-point arithmetic
In computing, fixed-point is a method of representing fractional (non-integer) numbers by storing a fixed number of digits of their fractional part. Dollar amounts, for example, are often stored with exactly two fractional digits, representi ...
and final output in all digital systems must be controlled to avoid saturation
Saturation, saturated, unsaturation or unsaturated may refer to:
Chemistry
* Saturation, a property of organic compounds referring to carbon-carbon bonds
**Saturated and unsaturated compounds
** Degree of unsaturation
**Saturated fat or fatty aci ...
.
Analog mixers, too, must deal gracefully with overloading and clipping at the microphone preamplifier and as well as avoiding overloading of mix buses. Noise
Noise is unwanted sound considered unpleasant, loud or disruptive to hearing. From a physics standpoint, there is no distinction between noise and desired sound, as both are vibrations through a medium, such as air or water. The difference arise ...
is present at all stages of an analog mixer, though good gain stage management and turning unused channels down to zero minimizes its audibility. Digital circuitry is generally more resistant to outside interference from radio transmitters such as walkie-talkies and cell phones.
Many electronic design elements combine to affect perceived sound quality, making the global "analog mixer vs. digital mixer" question difficult to answer. Experienced live sound professionals agree that the selection and quality of the microphones and loudspeakers (with their innate higher potential for creating distortion) are a much greater source of coloration of sound than the choice of mixer. The mixing style and experience of the person mixing may be more important than the make and model of audio console. Analog and digital mixers both have been associated with high-quality concert performances and studio recordings.
Remote control
Since the option first appeared associated with analog mixing the 1990s as wired remote controls for certain digital processes such as monitor wedge equalization and parameter changes in outboard reverb devices, the concept has expanded until wired and wireless remote controls are being seen in relation to entire digital mixing platforms. It is possible to set up a sound system and mix via laptop, touchscreen or tablet. Computer network
A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ...
s can connect digital system elements for expanded monitoring and control, allowing the system technician to make adjustments to distant devices during the performance. The use of remote control technology can reduce the amount of venue space used for the front-of-house mixing console, and recover space for audience seating.
Software mixers
For recorded sound, the mixing process can be performed on screen, using computer software and associated input, output and recording hardware. The traditional large control surface of the mixing console is not necessarily utilized. In a software studio, there is either no physical mixer fader bank at all or there is a compact group of motorized faders designed to fit into a small space and connected to the computer. Many project studios use such a space-efficient solution, as the mixing room at other times can serve as the business office, media archive, etc. Software mixing is integrated as part of a digital audio workstation
A digital audio workstation (DAW) is an electronic device or application software used for Sound recording and reproduction, recording, editing and producing audio files. DAWs come in a wide variety of configurations from a single software pro ...
.
Applications
Public address systems in schools, hospitals and other institutions use a mixing console to set microphones to an appropriate level and can add in recorded sounds such as music into the mix. PA mixers usually have controls that help to minimize audio feedback.
Most rock and pop bands use a mixing console to combine musical instruments and vocals so that the mix can be amplified through a nightclub
A nightclub (music club, discothèque, disco club, or simply club) is an entertainment venue during nighttime comprising a dance floor, lightshow, and a stage for live music or a disc jockey (DJ) who plays recorded music.
Nightclubs gener ...
's PA system. Among the highest quality bootleg recordings
A bootleg recording is an sound recording, audio or video recording of a performance not officially released by the artist or under other legal authority. Making and distributing such recordings is known as ''bootlegging''. Recordings may be ...
of live performances are so-called soundboard recording
A soundboard recording is a sound recording of a concert taken from a direct connection to the soundboard at the venue. Soundboard recordings are considered to be among the highest quality bootleg recordings of live performances though some soundb ...
s sourced directly from the mixing console.
Radio broadcasts use a mixing desk to select audio from different sources, such as CD players, telephones, remote feeds, prerecorded advertisements, and in-studio live bands. These consoles, often referred to as ''air-boards'' are apt to have many fewer controls than mixers designed for live or studio production mixing, dropping pan/balance, EQ, and multi-bus monitoring/aux feed knobs in favor of cue and output bus selectors, since, in a radio studio, nearly all sources are prerecorded or preadjusted.
DJs playing music at a dance club
Dance is a performing art form consisting of sequences of movement, either improvised or purposefully selected. This movement has aesthetic and often symbolic value. Dance can be categorized and described by its choreography, by its repertoire ...
use a small DJ mixer
A DJ mixer is a type of audio mixing console used by disc jockeys (DJs) to control and manipulate multiple audio signals. Some DJs use the mixer to make seamless transitions from one song to another when they are playing records at a dance clu ...
to make smooth transitions between songs which are played from sources that are plugged into the mixer. Compared with other mixers that are used in sound recording and live sound, DJ mixers have far fewer inputs. The most basic DJ mixers have only two inputs, though some have four or more inputs for DJs using a larger number of sources. These sources could include turntables, CD players, portable media player
A portable media player (PMP) (also including the related digital audio player (DAP)) is a portable consumer electronics device capable of storing and playing digital media such as audio, images, and video files. The data is typically stored o ...
s, or electronic instruments such as drum machines or synthesizer
A synthesizer (also spelled synthesiser) is an electronic musical instrument that generates audio signals. Synthesizers typically create sounds by generating waveforms through methods including subtractive synthesis, additive synthesis and ...
s. The DJ mixer also allows the DJ to use headphones to cue the next song to the desired starting point before playing it.
Hip hop music DJs and Dub producers and engineers were early users of the mixing board as a musical instrument
A musical instrument is a device created or adapted to make musical sounds. In principle, any object that produces sound can be considered a musical instrument—it is through purpose that the object becomes a musical instrument. A person who pl ...
. In the 1970s, hip hop DJs developed a technique of adjusting the fader and crossfader controls of mixers at the same time as they manipulated records on turntables, creating unique rhythmic ''scratching
Scratching, sometimes referred to as scrubbing, is a DJ and turntablist technique of moving a vinyl record back and forth on a turntable to produce percussive or rhythmic sounds. A crossfader on a DJ mixer may be used to fade between two record ...
'' effects.
Noise music
Noise music is a genre of music that is characterised by the expressive use of noise within a musical context. This type of music tends to challenge the distinction that is made in conventional musical practices between musical and non-musical ...
musicians may create feedback loops within mixers, creating an instrument known as a ''no-input mixer''. The tones generated from a no-input mixer are created by connecting an output of the mixer into an input channel and manipulating the pitch with the mixer's dials.
Gallery
File:Mark III radio desk.jpg, BBC #REDIRECT BBC #REDIRECT BBC
Here i going to introduce about the best teacher of my life b BALAJI sir. He is the precious gift that I got befor 2yrs . How has helped and thought all the concept and made my success in the 10th board exam. ...
...
SeriesTEN
File:GECKO EXODUS ODYSSEY MXR 5204L.jpg, Gecko Exodus Odyssey MXR 5204L