Introduction: How to Use an Audio Mixer (soundboard)

Picture of How to Use an Audio Mixer (soundboard)

In this instructable I am going to go through all the control features found on most mixers (mixing consoles, mixing desks, audio consoles, soundboards - they all refer to the same thing). I will start with the absolute basics:
What is a mixer?
A mixer, in its purest and simplest form, combines or meshes an array of inputs into a few controllable outputs (hence the name, MIXer). It is pretty much universal that mixers will have at least a volume control on the output. The vast majority will have volume or "level" controls on each input, or "channel." A great many still will have a variety of controls on each channel, from gains or trims to EQ and aux'es and buses and PFL's and more; don't worry though - I will go through each of these at least briefly.
When a new sound guy looks at a mixer for a large church, per se, he may feel overwhelmed by the oceans of knobs that may or may not be there. But here,I will explain what these knobs do, and you will actually find them to be overwhelmingly simple.

The first thing you need to know is that I will be dealing with moderate to large mixing desks and sound boards, with at least 10 channels (available inputs) or more. These are what you will see if you want to "run sound" for a church or venue or record music of bands, etc.

Step 1: Channels

Picture of Channels

The most important aspect of understanding mixers is understanding the channels. On almost all consoles, the channels are laid out in strips; the signal comes in physically through the back of the device, then passes through that channel's various controls from top to bottom, with the gain or trim at the top and the fader at the bottom. I will go through what each of these steps does in their own, well, steps.

Simply look at one of the black circle inputs (XLR's for microphones and snakes), then follow the column of knobs straight down. This is a channel strip.

Step 2: From the Top: Gain (Trim, Sens)

Picture of From the Top: Gain (Trim, Sens)

On any good size mixer there will be a knob at the very top (first one in the strip) labeled "Gain" or "Sens" or "Trim." These are all the same thing. Put simply, the gain knob sets the "input volume." Think of a water faucet: a full water "signal" comes in through the pipe (input cord), and the faucet itself (gain control) sort of limits the amount coming into the sink (mixer). Because of the way a sound signal is composed of several different sounds at different volumes mixed together, the gain will naturally eliminate some of the very quiet signals; unless it is set very high. It's like survival of the loudest, and the trim sets the bar on how present a signal must be to get into the mixer. For this reason, it is sometimes labeled as Sens., for sensitivity. A high gain will be more sensitive to quieter signals like soft overtones and even spit pops in microphones.

Using Gain
Many people make the mistake of mistaking gain for volume. This is wrong. Gain should be used just like any other control knob: to set the kind of sound you want and the quality, not volume. That is what faders are for. Additionally, any gain changes will also affect the sound in the monitors or other auxes, so be careful. If you don't know what those are, don't worry: I'll explain them later.
A common use for gain is to sort of even out or normalize the signal (calibration). This is done if you have a VU meter, which tells you how loud the output sound is. One would set your fader or output volume control to 0dB and alter the gain until the meter says the sound is at 0dB.

Step 3: EQ: Equalization

Picture of EQ: Equalization

For those of you who are new to audio, equalization refers to the control (boosting, cutting) of certain frequencies to achieve a better sound or to eliminate feedback or unwanted noises. The EQ section of most mixers will be located right under the gain control, and can consist of anything from 1 to 13+ knobs or 3 to 33 sliders.

Tone Knob: One knob that, when turned clockwise boosts high frequencies and lowers low, and vice versa. Sometimes called contour, and usually found on very small mixers.

2-3 Band: Consists of bass and treble knobs or Low - Mid - High knobs. I don't think I need to explain these.

Semi - Parametric: Usually a 3 or 4 band (Low, Low-mid, High-mid, High) containing at least one sweep. A sweepable control is one that has a pair of knobs: one chooses a frequency to boost or cut, and the other sets the boost or cut. The Frequency knob is called a sweep.The mixer below has one sweepable band.

Fully Parametric: Every band has a sweep to go along with it.

Graphic: These contain sliders instead of knobs. Each slider has a set frequency and is moved to change the presence of that frequency. These are not commonly found on channels, but are often found on the total mix (right before the output goes out). I have seen graphic EQs with 3 sliders and some with 31+ sliders.

As you progress in size from small mixers to large, you will find the amount of control over the EQ of each channel increasing. Many of the large boards, like the Soundcraft MH series, have a 3rd control knob on their fully-parametric EQ bands: Q. Just as the sweep sets the "center" frequency to be boosted, the Q sets how wide the boost range is. If you think of an EQ band as a line with a hill or bump in it, the sweep sets where the bump is, the boost sets how high the bump is, and the Q sets how wide the bump is.
Many digital mixers allow you to actually have a graphic EQ on each channel. You would select the channel on the screen, and set its EQ. These can be troublesome, however, if you need to quickly cut a particular frequency in a live show before it causes feedback and time is crucial.
I have told you how to use EQ, but not how to be good at it. Many times it is best for newbies to leave the EQ on flat (no frequencies boosted or cut) if possible. Mastering use of EQ takes experience and research. Remember, however, that it can make an OK sound sound good, and a good sound great, but it cannot replace what should be in a bad sound.

Step 4: Auxiliary Outputs (Auxes)

Picture of Auxiliary Outputs (Auxes)

Auxiliary outputs, or auxes, are incredibly useful tools. If you can, picture the signal coming into the mixer, going through the gain and the EQ, then hitting an aux knob. That knob controls how much of that signal from that channel gets sent into that aux out. On this board there are 4 aux outputs, thus 4 aux knobs on each channel. Each row of aux knobs controls the level of all the channels in its auxiliary output.
The most common use for auxes is stage monitors. Lets say that we have Bob on stage singing, and Joe playing guitar, and each has his own monitor. Lets also say we have Bob's voice plugged into channel 1, and the guitar in 2, and Bob's monitor in aux 1 and Joe's in aux 2. So, if Bob wanted more guitar in his monitor, we would go to channel 2 (where Joe's guitar is plugged in) and turn up the Aux 1 knob: this tells the board to put more of the signal in channel 2 into the device plugged into aux 1.

Two other common uses for auxes are reverbs (device that simulate reverberation effects) and subwoofers (loudspeakers designed to reproduce lower frequencies than normal speakers can play).

Step 5: Faders, PFL's and AFL's, Pre/Post Fader Auxes

Picture of Faders, PFL's and AFL's, Pre/Post Fader Auxes

The fader (present in small mixers as a level or volume knob) is used to set the volume of that channel's signal in the mix. It is the most basic component in any channel strip. Faders are essentially volume sliders, set in a logarithmic scale of dB (if you don't know what that means, ignore it). Faders are also used to set the volume of the buses, or subgroups, and the main mix or mixed mono, and VCA's if applicable. I'll get into those next step.

Auxes, you should know, are normally pre-fader by default. This means that changing the level of a channel on the fader will not affect the sound of that channel in the auxes. However, many medium-large boards have a button near the aux knobs that allows you to change them from pre-fader to post-fader or vice versa.
Example of pre/post fader auxes:
You are running sound for a rock band playing in a large room. Being the sound perfectionist you are, you have set up some subwoofers to help properly produce the low frequencies of the kick drum, floor tom, and bass guitar. The band also has monitors set up on stage. If you have the option, you will naturally want the monitors to be pre-fader, so that changes on the faders will not mess with the monitors. You will also, however, want the subwoofer auxes to be post-fader, so that the mains-subs balance remains the same after changing the fader settings. When you turn up the bass guitar fader, you want the bass signal in the monitors to stay the same, but the bass in the subwoofers needs to increase along with the bass in the main speakers.

Most medium-large size desks also have a headphones jack for the engineer to use headphones. You will also see a button near the fader on each channel labeled PFL. This stands for Pre-Fader Listen. This allows you to listen directly to the signal in any channel via the headphones, unaffected by the fader setting. You may also see a button near the aux masters (they set the total volume of the auxiliary outputs) labeled AFL. This stands for, you guessed it: After-Fader Listen. This allows you to hear the exact sound and volume coming out of the monitors or whatever else you have plugged into the auxes.

You should also realize that above the fader, just after the auxes, is a pan knob. This is simply used to "pan" the channel's signal to left or right. All the way to the left would put the signal only in the left signal, and vice versa, with the middle sending equal to both sides.

Step 6: Buses (subgroups), Main Mix, VCA's

Picture of Buses (subgroups), Main Mix, VCA's

Almost all decent sized mixers have at least one bus, or subgroup, many have up to 10 or more. Buses are, simply put, a routing system. There will be buttons near the fader on each channel for each subgroup, allowing you to assign that channel to one or more of these subgroups. Think of the buses is mini-mixes.
One very common use of a bus is to assign all the drum channels (floor tom, kick, hi-lo tom, hi-hat, snare, etc.) to one bus. This way, the engineer can change the volume of the drumset in the total mix without having to change each fader on each channel. Other uses include groups of singers (girls, boys; leads, harmony), instruments (main, backup; brass, woodwind, percussion), etc.
Just remember that changing the fader on a bus is NOT equivalent to changing the faders on all of its assigned channels. It simply changes the volume of that particular mix of channels relative to the entire mix. Channels can be assigned to multiple buses, and changing the volume of one bus with channel 6 in it will not change the volume of channel 6 in any other subgroups.

Each of the subgroups also has a button allowing assignment to the main mix. In most cases, you will want everything combined into the main mix so that you can control the total volume of everything with one setting. Sometimes, however, you may leave one subgroup by itself; independent of the main mix, for whatever reason may apply. Usually each subgroup will have a left and a right fader, allowing for individual adjustment of the left and right aspects of that mini-mix. The main mix will also probably be stereo. There will be two outputs on the back of the board for left and right mix.

However, some mixers have another button to assign the main mix and any and all subgroups to a "mono" fader. This is another output on the back that is a single bridged out between the right and left of the mix out. This allows you to have a huge amount of possibilities of setups depending on where you have channels and busses assigned and what you have plugged in to the back. The mono will "bridge" the left and right channels, causing all sounds in each to be played in both. It will also, however, leave alone any left/right settings set before it.

VCA's are confusingly similar to buses. However, it helps to remember that buses route, and VCAs are simply a control mechanism. Contrary to subgroups, a change in a VCA will be exactly like moving the faders of all its assigned channels. Thus, any post-fader outs will be affected: post-fader auxes, the level of that channel in any subgroups, etc. If post-fader auxes are used for other main speakers like subwoofers, than a VCA will allow change in those too; where a subgroup would not.
VCA's are found only in larger boards.


NellizS (author)2017-11-19

I really learn a lot from here.....

Wackymac (author)2017-09-24

We live in an "over 55" gated community and we have a theater club. We put on 2 shows a year. I run the mixing board and I have a question about labeling the channels for the microphones. What is the best way? Do I label them in alphabetical order using the character's name, or label them in order of appearance in the play. Any suggestions? We have a Mackie 24 channel VLZ4 .4 bus board. A year ago last spring we did "A Funny Thing Happened On The Way To The Forum" with 19 people miked on stage.

j450nn014n (author)2017-03-18

Wonderful. You filled in all the gaps that I had: busses and aux.

Stroover (author)2017-02-04

Right on! Thanks for this. I've always looked at soundboards as being overwhelmingly complicated, but you really simplified it a lot for me. To the point that I think I could probably tackle one. (I'm going to have to, since we need a sound man for a gig in a couple of weeks, and I've been elected)

XyriousIndustries (author)2017-01-14

Say i intended to record audio for a soundtrack using electric instruments, is there really purpose of a mixer?

JamesG156 (author)2017-01-03


I'm looking at building my own audio mixer from scratch and was wondering how long the faders should be. I have seen ones at about 75mm but that seems very short? What sort of size is on professional audio mixers? I am also not sure how much to spend on the faders. I would like them to be decent quality and accuracy but not audiophile quality. Let me know if you know of any good brands.


matthewm349 (author)2016-10-28

This is good i really love the instructions. Thank you.

HazelO3 (author)2016-03-14

Although I've seen soundboards in the backs of high school theaters and whatnot, I really haven't had much experience with them. There's so many buttons and switches that it's hard to even focus on any one thing! It's insane how complicated sound mixing can be. Your article really helped explain the audio mixers a lot, though; thanks for all the info!

MalM4 (author)2015-09-04

Hi, I have an old powered mixer with passive speakers. 400w rms. the desk also has balanced outputs ( XLR male) which i am hoping is like a line out. I am guessing they are for running a signal to another amp to power monitors. I am proposing to run powered speakers from them, i did a test run for 5 minutes but didnt want to damage anything so I halted there. How right am i? the main outs run passive speakers using a speakon connector and as its only an 800w amp ( or 2 x 400w rms) i assume it couldnt split the power any further. I have a gig coming up on the 10th and need an answer. If i was running 400 watts into a 400w powered speaker i assume i would have seen smoke. they seemed to run normally for the 5 minutes i ran them. do you have any advice as to how i can make sure its a line signal? or would it be safe to say it IS a line signal and that i am safe to run as is? any help would be great as i dont have a book on the mixer. thank you so much and please may i have your attention asap. I have googled and googled with no luck.

JosephF43 (author)MalM42016-02-07

it's been a while since you asked so you may already know the answer, but line out is safe for your application. Old mixers sometimes make a little noise/hum out of these outputs. Just be sure not to use amp out or headphones out on old gear. Those contain some amperage usually.

tgray1 (author)2015-11-12

The Aux section on an Alesis MM8FX is labeled "Send"

Aruna5 (author)2015-02-25

I am beginner to PA system. In our church we are using Yamaha MG 166 CX with two speakers but the performers feel that need a proper feedback. Earlier we were using powered mixer (mixers with buit in amplifiers) with two small speakers. Can I take a out from my mixer (phones) and in to powered mixer. I tried it, it works out but i am looking for a technical guidance will it leads to any troubles. Please reply me.

Dave85 (author)Aruna52015-07-27

Yes you can. A non powered mixer sends out a plain signal referred to as a "line level." A powered mixer should also receive a "line level" which it's getting from your unpowered mixer.

BlakeM4 (author)2015-06-23

I'm currently using this same board at a small theatre, however I do not see on it how to make the two FX knobs work as 3rd and 4th Auxes. Any tips on how to make that work? Could I use the subgroups on the board?

glennthegeek (author)2015-04-30

Question about subgroups on using them for podcasting. I have two hosts with mics in to two different tracks. Also, have two computers into the mixer using Skype. I have a mixer that allows 2 subgroups with separate outputs.

Question is could producer take a call on Skype on one of the computers by connecting her track with 2nd computer track through a subgroup, talk to the guest on Skype (off air) away from main output. Then when the guest is ready change it so the 2nd computer skype guest can be brought into the main mix? Sorry if it is so confusing. (author)2015-01-29

HI....Great Explanation

please help me to buy these products...

i need yamaha 16 channal mixer --- 1

jbl speakers ---- 6

shure cordless mics ---- 5

shure podium mic ----- 1

suggest the models names to buy....

gladwyn.graham (author)shaker.kp2015-02-17

A yamaha mg16xu will be good
and the shure pgx2 with the sm58 mic will be good
just search on sites like or something

cliff.haggerty (author)2014-12-23

The best explanation of a mixing board I have found to date. Congratulations. Like *****

jc tyler (author)2014-12-18

Was looking for a related topic - excellent introduction to soundboards - it's simple in the sensen that a complex thing is explained correctly and with common sense.

idekmae (author)2014-11-07

im wantinf to create electronic beats essentially, what kind of mixer would you suggest? and what would the proce range for that be? would a digital mier be better for that purpose?

reggie.mcmillian (author)2014-07-30

I can not get sound from my 8 channel line mixer amplifier

joeltan111 (author)2009-10-29

I love this tutorial....
going to use it for teaching purposes. 
But, i wish to ask if there are any guides or tutorials which detail the operation of a digital board, as this guide is focused on a analogue board.

Iron Cowbell (author)joeltan1112014-05-14

This response is 4 years to late, but as of right now it would be difficult to create a guide like this for digital mixers as they are all different. If you want to use a digital one then you will need to find information specifically for that board.

sdmccoy (author)2013-02-18

Thank you so much for this. It is so simplistic and I'm glad I found you. Know I understand what I am suppose to do/be doing.

musicmike1 (author)2013-01-19

You mentioned headphones here. I wonder if you could answer a question.

I have a Kam KMD20 and want to hear the applied effects through the headphones and but seem to find out how to do it.

Any ideas?



yoyology (author)2012-11-25

This is extremely helpful! I run video for our church's Praise and Worship service, and if the sound guy doesn't show up, I'm left sitting next to the mixer and shrugging when somebody asks me to do anything. I need to get a basic understanding of the board so I can run it in an emergency, and this is just the intro I was looking for. Thank you!

_Basse_ (author)2009-03-07

Can anyone recommend a "begginer" Soundboard ?

davidprosser (author)_Basse_2009-06-14

It all depends on what you're using it for. So, how many mics, instruments etc and what it's actual purpose is. Tell me that and I'll give you a recommendation :D

Buck2190 (author)davidprosser2010-01-11

David, my purpose is home recording of "live" instruments. I have been jamming with some friends and we are now interested in recording our music. We would be connecting an Akai XR-20 drum machine, an electric bass guitar, a MIDI keyboard and possibly a microphone. What is a good mixer or soundboard that you would recommend for that. I have a lead on a Studiomaster Club 2000 14x2 for $200. Is that a good buy?

davidprosser (author)Buck21902010-01-12

Yeh, that's a good bargain if you can get hold of it. You will need  fair amount of cables too. If you're looking to record digitally (idealy) you will need a way to connect the desk output to the computer sound card for recording. This can be done by connecting the stereo output of the desk into the line input on the computer, and use a simple program like Audacity (free) to record your session. The drum machine outputs in stereo (two channels) so you'll need two jack cables to go into the mixer. The same applies for the keyboard I would think (if it has a stereo ouput). The bass guitar can be run directly into the mixer on a jack cable like the other sources. The microphone will use one XLR cable. Ideally, you want to keep the jack sources on as shorter leads as possible, as they can easily pick up interferenace from other electronic devices, but the mic can be on a long lead.

So yeah, that desk should be fine! The only thing is that you'll be recording on just two tracks, so everything you record will have to be balanced correctly on recording to give a good sound output. You can kind of cheat with multitrack recording, my recording each track one at a time, and then layering them all together on the PC. This can also be done on Audacity.

Good luck!

wouternet (author)davidprosser2011-04-10

This may be old, but you can NEVER plug a bass or any other guitar direct to the jacks on the mixer. It will sound horrible! This also applies for Pianos. You have to use a DI-Box (Direct input), converting jack to XLR

lvsloan1 (author)wouternet2012-09-29

Our praise and worship band always plug directly into our mixer. We go from the mixer to powered speakers & have a great sound. The ONLY problem we have is the Behringer mixer started loosing 2 of the channels our mics use so we went w/ a Mackie PRO FX 16 mixer. MUCH BETTER!!! Our Church uses a Mackie PRO FX 22 mixer. We plug everything into a 16 channel snake which then runs to this mixer. Same as our band, great sound. We did however install DI boxes to take the noise out of the system. I hope we get years of service from the Mackies as this is our first time going to that brand. I trust Behringer powered speakers & amps but have too many friends that have had trouble out of their mixer boards. I really enjoy this forum 7 will definately have to lean on some of you from time to time as I've been a drummer since the 70s but am just now starting to learn the mixing end.

davidprosser (author)wouternet2011-04-10

Hmm, that only applies on instruments and keys that are cheaper and so don't have a "true" line out as far as I know, otherwise there would be no purpose in mixing desk manufacturers having line ins on their desk, no?

wouternet (author)davidprosser2011-04-19

Easy, it can be used if you want to plug in an iPod or CD player. You can go from <3.5mm minijack> to 2 (a red and white one) You have to use 2 channels, one for the white (left) and one for the right (=red). Make sure you set the balance for the channels respectively far left and far right.

I've never come across a piano with XLR. After reconsidering, yeah, a piano might be able to plug in directly. But we (my soundcrew) always use XLR because we don't have jack-jack cables that are over 50feet.

Only acoustic guitars with an element with XLR can be plugged directly in a mixer without a DI. (not very common, mostly only jack)
The Jack from a guitar gives a different impedance and voltage, and it will sound very crappy.
A DI is small pre amp converting it to XLR, using a 9Volt battery or the 48volt from the phantom.
Also, an electric guitar draws his current from the amplifier, and if you plug it in your mixer you might blow out some fuses.

brianhoorn (author)davidprosser2010-10-04

If you're going to record separately and layer everything together, you might as well save on the $200 mixer, use a preamp, and do everything on your computer. I'm sure they have some good software for Windows if you're using a PC that isn't as costly as Pro Tools. If you have a Mac, GarageBand works fine, perhaps with a few more programs you can get for free. I use Logic Studio. It has tons of great tools for mixing, and a whole lot more.

roscoerules (author)davidprosser2011-05-09

I would like a 3-input stereo line input mixer (simple and cheap as I can get away with) to combine an mp3 player, my laptop, and a white noise machine. Thanks, I appreciate any and all suggestions you may have.

davidprosser (author)roscoerules2011-05-10

Depending on the the connection (ie as long as you can get them to quarter inch jacks, you should be fine) then these should be suitable. The first is about as basic as it gets, the second adds a mic channel and some control if you need to get a bit more customized, the third has a few more channels in case you feel the need. These links are for the UK retailers but they'll all be available on global sites. Have a look, hope this helps:

roscoerules (author)davidprosser2011-05-10

Thanks very much!!
Take care,

It all depends on what kind of things you are looking for the board to be doing, if you give me some sort of idea what you want and I can give you some recommendations.

07511 664218

idkdoyou (author)2009-06-17

do you have to use a coputer to record your music and do ect.........

brianhoorn (author)idkdoyou2010-10-04

It's actually arguable that you don't even need an external audio mixer. There is software for every computer operating system that can produce the same effects. I have an iMac with Logic Studio. All I use is a small preamp for my microphone and my friend's guitar. Pretty much everything is done on the computer.

bc.suganth (author)brianhoorn2012-05-19

your explanation is very good !!
and you are correct that there is no need of external hardware !!
In olden times , the computer processing speed was very low . so they used external electronic mixers . If you have a powerful pc you dont even have to use hardware mixers !! right ?

coocoo48 (author)idkdoyou2009-10-16

not always but most people recomend it if you are not able to use a pro sound recording system

tiberiustibz (author)2012-05-05

It may not look like it, but this sound board has 28 channels.

Braedenb13 (author)2012-04-14

Hey, I run a tech booth at church and we want to start recording sermons and putting them on the Church Website for home-bound seniors. We have our computer and we have a 16-channel soundboard. If i wanted to record it, could i but a XLR cable that converts to a 3.5mm Jack and plug it into the microhone jack in the computer, and record it that way in Audacity, and upload it to the Website? I just want to know before i buy the cable.


thegeeke (author)2011-08-28

I know that this instructable, but incase anyone is still looking at this, NEVER waste your money on a berrienger (sp?) board. Anyone who knows anything about sound would agree.

dog digger (author)thegeeke2012-01-20

agree. No matter what I would be for. The Behringer Xenyx mixers are a bad quality copy of mackie onyx boards!

thegeeke (author)dog digger2012-01-20

Any berringer board is a copy of another decent board. Berringer just takes good boards and fouls them up. They will use the exact same design, except with the cheapest parts and labor they can find. I'm told (I never actually confirmed this) that Makie actually won a lawsuit against berringer because whoever had designed the Makie board had too much time on their hands, and if you looked at the circuitry from a few feet away it spelled "Makie". Makie opened up berringers board in the court room, and sure enough, the circuitry spelled makie! (I guess you could say berringer copied the board "to the letter"!) ;)

psychodalek (author)2010-10-18

im with sliff. i just need to know the basics of what to buy to create sound blends and mixing like Bassnectar, Reso, or Deadmau5.

dog digger (author)psychodalek2012-01-20

You need a few things. You need a dj mixer, midi keyboard or any other midi input device OR a synth pad like a Native instruments maschine and a laptop with software (pro-tools or something like that)

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