Yamaha MG20XU mixer training part one

all right so hello everyone thanks for coming first of all a brief explanation of the difference between analog and digital right so with an analog mixer the signal is transported and processed in the analog domain right now what we mean by that is so a microphone converts sound energy to electrical energy the electrical energy has a voltage that is directly proportional to the volume of the sound right in other words the electrical signal is an analogue to the acoustic signal right that's what we mean when we say analog digital is ones and zeros okay you may understand you know computers only they only know two things right their circuits either on-off so it's either 1 or 0 so that's that's the difference now some analog mixers have a digital section to them so for example on this one even though it's an analog mixer it has a digital effects section ok which we will have fun with later and a lot of amusement hopefully but in general the signal goes through in the analog domain right it's never converted to ones and zeros the conversion for digital mixer typically occurs as soon as it goes into the mixer some digital mixers they have a stage box which sits on stage and the stage box contains the analog digital converter and the two are connected using cat6 cabling right it's much simpler than running all of this and a lot copper alright let's move on to this particular mixer so what I'd like you to do is just study the way that this mixer looks for a moment alright so you can see that the mixer is organized in two different directions right it's organized from top to bottom and it's organized from left to right ok so the first thing is that all analog mixers are divided into what is called an input section also called a channel section and a master an output section alright this is where all the signals come in that's why they've painted this section black this is where the signals leave the mixer right any mixer including the older Mackie is organized this way the other thing is can you see that the mixer has columns of knobs yeah do you notice that every column is the same yeah do you notice that from here to here the first eight columns are all exactly the same do you notice that okay each of these is called a channel right each channel is one signal source okay does everyone understand that that's very important because some people they get very stressed when they see are you I've got to learn all of these knobs actually all you have to do is you just have to learn one column once you learn one column they're all the same alright the most complicated at the first eight you can see that here you have four more that don't have the yellow knob and then you can see at the end you have four more that are missing one of the green knobs okay so this mixer has lots and lots of channels you learn one you learn them all okay now do we remember from last week the difference between stereo and mono mono is one sound source there's no left/right information stereo is two channels and they must be 11 right so the first 12 channels on this mixer right to this point are all mono channels okay and you can tell that they are mono channels because the input does not have any left/right designation to it the last four are all stereo channels all right and the reason is that there are two numbers next to each input so you can see that this is 13 14 15 16 and so on alright so the name of this mixer is mg 20 all right how do you think they get the number 20 right correct is 20 channels right but if you count the number of faders you don't have 20 faders right so what you have is you have 12 mono and you have 4 stereo 4 times 2 is 8 12 plus 8 is 20 that's how they get mg 20 all right mg is the series mg series is the entry level for Yamaha Xu means that it has digital effects on board right there are some which have no.you at the end and those this section is missing there cheaper all right good so that's the overall big picture of the mixer the first thing that you have to appreciate about this mixer is that the input connectors do not line up perfectly with the channels all right can you see that one lines up with one but by the time you reach 8 can you see that it is here and the connector for 8 is not directly in line right the worst is over here you can see this is 19 and 20 and the channels okay so you must be quite aware of what you are manipulating there that's the reason why they've given you the numbers here as well as yeah all right so we're plugged in to 8 so we'll use 8 for simplicity sake all right so to begin with at the top just switch the channel off so you have an input connector alright can anyone remember what this style of connector is called combo connector the reason is that it will accommodate a normal accelerometer in the middle it will accommodate a quarter inch connector all right now these four are not combo there's no hole in the middle so don't go and spend half an hour trying to plug one of these in there all right okay I'll be very honest with you the reason that they went to this it used to be that mixers always had an XLR and separate quarter-inch connectors the reason they went to the combo connectors is just cost right it's cheaper to put these than to have separate connectors it also allows the mixer to be a bit shorter all right in the old days you had a whole series you had you had a mic connector align and insert and several other things right but they've they've streamlined it nowadays okay so we have our input connector below them you have two switches here you have a pair and this thing called hpf high-pass filter all right we'll learn what that does next we have a gain control now your seniors would have taught you a bit about this last week all right we learned that this increases the level of the signal below that you have what's called a 1 knob compressor this is a Yamaha thing alright and it controls the dynamic range we'll learn more about that later then down here can you see this switch that says phantom plus 48 volts now this switch switches on something called phantom power which is power for condenser microphones and active Direct buses okay this switch is usually somewhere here but I think they had extra real estate so they put it here ok if you're operating condenser microphones active D eyes you would switch it on right and if you're not you can leave it off very important when this is on don't plug and unplug stuff because you get big bangs going through the sound system and Vanya will hunt you down yeah with that face all right then we have the green section this is the equalization section also known as your tone control below that you have the blue section blue section is called the auxiliary section also known as the aux section below that you have a pan control excuse me sorry yeah pan control which is red you have a channel on an off switch fader and this down here which is referred to as your channel routing buttons and right at the bottom you have this pfl switch okay PFL stands for can anyone remember yes thank you everybody's a pre fate listen all right now over here you can see that you have four channels which are missing the one knock compressor okay there's no other difference the reason is that Yamaha apparently could only afford eight of them so they left them off this channel okay it's just like that then here at the very end you have four what they call stereo hybrid channels so the older Yamaha mixers had stereo only channels meaning that they had connect us like this only alright this new model Yamaha has gone one better they have given you channels that have an XLR connector and they have a pair of stereo inputs so these here are unusual in that they can accept either mono or stereo signal right so you have to be aware of that when connecting these here can accept an XLR or quarter-inch balanced or unbalanced these here same you know they will accept maybe not this one right some something like this right so here you if you were to use these to connect a stereo signal you would have to use two of them right because if you have left and right with these you can connect to a single channel because that's two here alright this mixer also has a USB input which is accessed by a connector on the back panel alright the USB input can be routed to the last pair off stereo the last stereo channel so there's a switch here in its up it says line down is USB alright so if you are using the USB input then this takes the place of that so to begin with we have connected our sound source the first thing that you need to do whenever you plug something in is you want to set this not the gain correctly so the word gain is the amount that the signal is increase when it enters the mixer so the audio coming out of a typical mic is very very small it's may be 0.001 volts okay some condensers may be 0.0 one but the point is is that this is too small for the mixer to handle the mixer operates at around one volt so you need to boost the signal in order for the mixer to modify it so that's what the gain does the game boosts that tiny tiny signal to the point where the mixer can deal with it if you set the gain too low you will have no sound if you set it too high you will get distorted sound all right I'm going to teach you something called gain setting procedure and then we'll get a couple of you guys to do that so first thing is make sure that the channel is off okay now on some mixers there is a mute button this is something that manufacturers cannot agree on some manufacturers use a on button some use a mute button if your particular bought uses a mute button you want to press mute okay in this case we have on this is actually a better system right in my opinion so as long channel should be off okay master fader should be at zero channel fader usually we leave it all the way down right but if channel is off it doesn't matter where the fader is then we press the PFL button okay when you press the PFL button you can see that this starts flashing right now what that is for is to warn you that you have pfl one of the channels the reason for this is that now this meter is showing the input level for this channel if this is not engaged the meter shows the output level of the whole console the other thing that this does is it routes this channel to your headphones so that you can hear just that channel so for example if you have five singers and you want to find out who is singing out of tune you can go through and listen one by one so the next thing that we do press pfl you you top or you're talking to the microphone or you get the artist to sing and then you raise this until the meters are right touching zero okay check one two three four Mic Check one two check check one two three four check one two can you see that right um don't agonize about this okay some people you know they like gotta go exactly it doesn't matter okay as long as it's around zero the point is is that you don't want it you you you don't want it way down there and you don't want it where it's hitting the top okay you want it kind or on kind of round there okay on most mixes for vocals this will be between 12 and 2 o'clock okay four instruments it's usually a little bit lower right 10 to 12 that's just a very general rule all right then you set your game then you can switch off this and you can turn the channel on and you should have sound check check 1 2 3 4 ok now if you forget to switch the channel on then obviously you will have no self right briefly explained these two we have Pat and we have high-pass filter ok so as you can see the pad switch drops the input level by 26 dB okay so if you find that with the gain all the way down you are still over 0 okay and this will happen with very powerful inputs typically things like keyboards some CD players will do that ok so I can't really simulate it with this but if you find that with this all the way down check check you are already over you will put that in and then you will find that it gives you check one two so you can see that now even with it all the way up I can't hit 0 ok if I take it out you'll see that I'm I'm way up there so this is it's useful when you find that the input is too hot for the range of the knob ok other offenders are kicking snare drum okay kahan as well sometimes so that's what that's for obviously if you find that hey how come I have no gain sometimes you've pushed that in by accident this one here high-pass filter it removes everything below 80 Hertz in other words it removes the low frequency information that is not useful in live sound so that area below hundred Hertz there's no for vocals unless you're one of these bass singers right there is no useful information down there so you switch it in all the time right what lives down there is things like bass guitar kick drum air conditioning noise big trucks going by that sort of thing alright so generally speaking these should be pushed in for all of the inputs then if you have bass you'll you will let them go all right okay now then we come to this thing here which is called the compressor the reason it is here is that this is where is in the signal path so it's placed after gain before the EQ section right the the signal literally flows through the circuit board in this order so from the top it flows to the bottom and then it flows across to the master section so EQ Equalization if we have so this is 20 Hertz and this is 20 kilohertz okay this is the range of human hearing okay so generally speaking you know in this area here this is bass okay this is treble and this is something called mid-range so on this board you have as you can see here you have a low a high and something called mid right what I'll do is I'll draw the effect of those controls for you on the board so you can see right this is your low control plus and minus right when you turn to the right or clockwise this is what you are doing to the tone curve turn anti-clockwise right this is called boost and this is called cut the high or treble does this so you have plus and minus this is excuse me this is high now your mid-range is interesting okay because the mid-range you have two controls you have a frequency and you have a plus/minus the shape of the curve is also different okay so these are called you can see that these they look like a shelf they call the shelving EQ this is different is called a peaking EQ right the other thing is that this curve can be moved to different frequencies alright so the technical term for this is swept or semi metric mid okay now this diagram is for those who like to geek out on this you don't really need to understand this what you need to understand is the effect that the controls have okay so first we do low and high so the first thing that we have to establish is that the 12 o'clock position is where you always want to start okay and this is called flat I know it the reason is not that that the sound is if you say flat to an audiophile they have an aneurysm because it sounds uninspiring it just means that you are not altering the tone curve right that's why we say flat okay so let's start with low so if I turn the low knob clockwise do you expect my voice to get base year or less bassy base year okay let's try check one two three four five six yeah sounds sorry yeah so that's a good example of why you don't boost too much I'll bring the gain down sorry Maria okay one of the things you have to understand about EQ is that EQ is frequency selective gain so in the same way as if you turn the gain too high it will feed back if you boost too much EQ it will also feed that at that frequency okay so we've brought the gain down a bit so we don't destroy people over here if I go the other way how will it sound less Basie let's try check one two three four five six yeah okay hi let's have a look check one two three four can you hear the difference yeah some some people call this clear others will call it sharp or piercing or whatever go the other way check one two three four can you hear the difference yeah sounds like I'm kind of underwater right so one of the things that this should have taught you is that in live sound you can actually achieve one thing by doing another and what I mean by that is you can give a sound more apparent bass by cutting the highs in the same way you can give a sound more apparent treble by cutting the lows all right one of the rules in live sound it's a rule that is often broken is that we want to try and cut rather than boosts because boosting in live sound can lead to feedback very easily cutting is always safe in that sense okay so we'll do the mid-range then I'll get some people to come up okay now mid-range the mid-range as we have said can be swept to different frequencies the low and the high are fixed okay the low and this board is fixed at a hundred the highest 10k with the mid-range it is sweepable from 250 which is down here up to 5k which is kind of tribally right so we'll leave it in the middle the middle is about the middle is a thing 1.5 all right this is what treble sounds like this is the boost check one two check check one two yeah okay not a very pleasant sound okay check one two check check one two this going the other way so some people refer to mid-range as clarity some people refer to it as honk enos okay it just depends all right so I'll teach you a technique for adjusting mid-range and it goes like this so the first thing you do is you I'm just gonna bring the level down a little bit so the first thing that you do is you boost the plus/minus quite a bit okay so here will boost this check check one two so you can hear the boos all right then you sweep the knob the the frequency knob which is moving the curve back and forth you sweep it until the sound is as bad as possible so listen so we'll start all the way down mm-hmm in here it's trying to feedback check check one two three four check one two three four five six check check hmm you can hear there's a problem there sounds awful check one two three four okay so we have a problem check one two there and we have another problem somewhere ah can you hear it's sounds really horrible there so then what you do is you move this control from boost to cut listen how it changes the sound check one two three four okay this is flat check one two three four can you hear how the sound cleans up right so this is this is a technique that is often used to find problem areas with the human voice there is usually a problem somewhere around 350 400 Hertz and there is also typically another problem a bit higher maybe eight nine hundred okay but the number one rule is if you do not know what these knobs do just leave everything at twelve o'clock okay because that way you are not changing the original signal okay good you

Channel: GLB Productions

Views: 137,872

Keywords: live sound, sound reinforcement, training, Yamaha, MG series, MG20XU, mixer

Id: 2wUJSmSbZks

Length: 25min 5sec (1505 seconds)

Published: Wed Feb 05 2020