Lessons

Lesson Info

Waveform Basics

To begin with we're going to start with some extremely low level stuff but we need to ensure that or we have the proper terminology built up to get cover the pretty deep stuff to talk about later so for the three audience members we had here today actually pretty sure this is going to be uh known stuff but for the surely billions of people who are watching this right now some of you might requires such a refresher anyway we're going to begin today talking about the thing with the button that tells us yeah way foreign basic since attractive but this is these are things that um terms that you might be familiar with especially attractive to this is that something you hear about a lot and um while some people are really familiar with it in terms of and you know relative other kinds of this is so tragic that this is added is that this is fm this's wave tables emphasis all these things attractive is president in all of these even though they are very different things so to understand that is...

to understand a huge swath of just a lot of how sound decide works so uh covered begin covering that kind of thing I wanna talk about um that's right? We're talking about everything they were talking about also so that later once we koplovitz once recovers attracted so this is where you can talk about other kinds of this is before we get there that we're going to take a little detour and talk about compression and distortion which you might think are not super related, but turns out they are a lot after that we're going to cover out of this or is this as we said different kind of separatists, but we'll find as kind of segway into it that it does relate a lot of practice and this is just a little bit differently. S o bunch of examples of things you can do with both concepts combined that's a really cool stuff in something you might not have expected next day they too will begin with the fact that this is which as a topic is one of the more complicated things to kind of apprehend around, even though it mostly just none too. It was not so much as difficult, really hard to kind of keep in mind, it's just things that you might not have considered they were talking about vote coating, which is a big part of sort of popular sound design and to get, you know, kind of the growling talking since that's, the easiest way to do that is with bogota so pristine for stuff there and then later we're going take sound design requests mobile taking will take the request today, and then we will pick a few that we like and then we'll go about creating them this sort of show you how you go about doing that and then once we do that kind of thing we're going start talking about actually how you could use yourself how you could listen to a sound and figure out how to rivers and hear for yourself which is about as hard as it sounds so that they could that anyway let's begin with the actual segment for right now which is way formations now I have here a set up on the screen that shows uh also later persons set up in something just to generate some sounds good times um people is that the idea it's funny I saw this tutorial someone made like two or three days ago about wave forms versus sound waves and it's kind of interesting that you would want to separate the two which I guess technically it's true. But this is sort of an interesting concept and this is like the most pure basic idea of how sound works and how we hear sarah how those waves happening in the air, that kind of thing you get four years not sort of deal and what this represents when we see it on and oscilloscope which is to say something that could show us the oscillation and what is an oscillation? Well, um an oscillation is something that oscillates just moves up and down thought into that just does this is actually what speaker comes to when they create sound and the whole idea is that it moves back and forth to create movement in the airway pushes air and then stops pushing your aunt's house pushing her again and that kind of thinking that change in air density moving through space is a sound wave on the way for me to speak of conners but creates that way so for example we're looking at what I got out here which can do tio right there that it is a sign wave it's one of one of the four basic way forms um individual sine wave represents one individual frequency a frequency is the how fast the way forwards also also ending was which is the measurement of its value its tone and there are other measure with ticket that could be applied tio any kind of sound the amplitude and you know just how loud of this I kind of think but one big important part about sort of a way form is this idea of speed and pitch which was such a what it means is that if it's a hiring pitches just going faster and slower and benches moving slower and that's really all there is to that that might have you might be thinking well dear, obviously but this is that I should become super duper important especially we start talking about fm um e about so we have the sine wave another of the four basic ones actually, I like I like citrus for this particular for purpose throng operator. Actually, I don't remember the thing I want to talk about and that's this idea of using oscillators for more than just sound in in the analog world, everything, every kind of control sources, some kind of oscillation and as producers, you may be familiar with the concept of a lfo, which stands for a low frequency oscillation or a loafer get jobs later, and then you can put that to a parameter and make it move around a little bit down and repeated constant motion that you have control over and in sort of like the analog world that's the difference between a low frequency oscillator and just your regular average out slater's there is no difference, they're the same thing just one happens to be really, really slow and there is a classification for how slow it is. The low frequency oscillation is where it's too slow for you to pick out a tone you're not able to determine that it's a note came or you're actually able to hear individual movement as opposed to it's so fast that it sounds like one note which is what's referred to as audio rate oscillation, which is against the bill becoming super important when we start talking about fm which seems interesting that I'm waiting all this out now, even though we're talking about five until tomorrow, but it makes sense, believing anyway, this way for that we're looking at right now is trying a wave, which is just pretty easily seen white. Um, one thing I wanted to show when I play these things on the screen, is that the sort of the harmonic content of the of the few I mentioned, women play a sign wave represents a single frequency, and in equalizer beneath citrus, we can see that it is, in fact, a single frequency, pretty straightforward how we're gonna try go with while still a single frequency of the way form. It is the same oscillation over and over again way have more than the front, the one frequency we have a whole bunch of different frequencies. And these are harmonics. And these air thiscreate, that's, how about content is what builds up to create the way form that we see which become super important. We talk about additives, and this is kind of a preview of that that's assault wave. That guy right there saw wave is a very interesting way from look at for a lot of reasons, primary one being the in the concept that's attracted to this is a saw wave is pretty much came and the only other sort of important way form that its president for this like this concept is the next one then we can look at which is a square wave but look at the harmonic content of this hallway for a second a lot of a lot but what happens when I go to square with it sort of loses some harmonic value and it appears to be a even kind of way it turns out it has half of many harmonics as this always does and that would come in and eat again later so many things all these things will build up to such incredible ridiculous things that you would never have thought of unless you know you already know the stuff in which case you know, talking about and you're should be excited but let's go back in a solid second because you may see in the citrus window versus what we look at in the cell let's go. This telescope has this kind of mess going on this little kind of gucci business happening near the tail end of it first is the perfect, you know, does walls of sound that supposed supposedly what it's always um and this actually has to do with the next thing that we talk about, which is the concept of band limiting which is on relation to how digital sampling works the hole which is super freaking cool a lot of people have this idea about about about sampling is, you know, and relative to analog playback, like taper record, so about that, and they have this concept of sampling and being boy, you're taking well moments of sound data so many times a second turns out, on average, forty four point one thousand times a second, which is a lot, um, that it's just taking a little bit little bit so the prices so fast that we're not able to tell that's taking little bits, but with this idea burst, ole taking to the limits is that the whole thing is that everything we're losing information and that's up entirely true sometimes true, but for the most part, not so much. And we can look at this by observing the recording of assault wave in a different environment, so we get rid of this was gonna open up. It isn't that we're gonna record us all with a zoom in for an african, as you see that mess that we're looking at in the oscilloscope, what would have been far enough? We can see the individual samples, and it was kind of the source of the mess of the fact that the sharp fall off of the salt wave is not actually a sharp is you might have been led to believe. It's a bit different for every plug in a generator solid than all the same but for the most part they're pretty similar they have this sort of this sort of business going on, but one thing I definitely want to look very closely at is how these little dots these samples are behaving with line is going on behind it so more that line behind it is actually the wave form that's being put into the speaker for the move to create the sound that you're hearing that's the signal that's what's going out now how did I know to make that signal? Which is an interesting question because you look at that that's some of them are like in the middle of the curve really does occur between and next dot like that they're not straight lines in between the dots that don't like where did that information come from? How did they know to put it on a particular movement in which mean those points and this has to do with the concept of bad limiting as it turns out, when, um we're doing sampling of recording or a generation of some kind what it's doing is it's solving for these points it's essentially playing connect dots with the points but and instead of just drawing anything like a possibly fit with the points what you could do yourself and just do whatever you want it has one constraint and that's the bad limit and the band limit is essentially the highest frequency is able to produce and this is what's referred to as the banquet split which is the highest regions that you could have given a sample right, which is half sample so for forty four point one kilohertz which is what we're doing now the highest level rate is half that which is twenty point five. Yes, a new math um so you know there's a bit a bit above the limit of human hearing which I have to imagine is the purpose of having chosen that as a standard just to make it easy you could of course have higher sample rates have higher frequency response now hold the whole deal. But um what that means is that when connecting the dots if you were to move even a little bit from this particular configuration of samples it would create frequencies higher in the nyquist and it knows this. So when it solves for these points it's has to solve for a particular solution that creates a sound that does not go above nyquist of which with the samples there is only one and this is what it does this way it is this is a little more impressive when when it comes to analyze recording I got all this information that I just said to you from video guy did on ziff dot org's youtube's, if that our example, you'll find it's pretty great and he has he had his whole so that we can analog oscillator run through sampling going back out to analyze telescope, and it was noted that if you put out a one kilohertz sign away that came out a perfect one kilohertz sine wave iran, which is to say that sampling is more than good enough to create, to recreate basically what we're what we're doing except for when we get to something like a salt lake saw wave is interesting sort of case study for the limits of sampling but then also kind of limits of this sort of speakers in general because if you think about what I saw way it does or square away even it's kind of physically impossible for us speaker to do that um because you know the perfectly straight line of being here is a point here's another point to the same point in the same time but the two different places and speaker cannot do that it will try to do that as hard as you can but and if we were to record the results it will look something like which is why um you know the playback and recording of assault wave in a sense is usually something a bit more benign like this particular thing and of course this limitation they were looking at is because basically the result of ban limiting is that, you know, with the line that input into the evidently straight line would mean infinite frigates in response, and if we had it in the frequency response that we could do that because that could mean that the speaker is moving infinitely fast to create is higher figure genes you could possibly imagine and that would result in your perfect always does that happen? And this actually is the supplies too kind of mastering as well, which is definitely not something that I think of because sometimes when your master contract it might might occur to you, why don't I just let it clip south canticle? Well, on the clip I've done this and I have learned why, and this is because when you clip something, you get perfect digital distortion, which is to say that you're making a signal now that it has created old ultimate square waves and like we just said, speakers can't really react to that uniformly so way, while my time okay in your particular setups attempt to recreate it it's not going to sound wonderful and everyone else is going to be consistent, but I think like this, this particular kind of solution doesn't believe that will sound uniform because it's forty four, point one kill her band limited and pretty much every even the shittiest of iphone iphone solutions will you know be designed to work with forty four point one killer that's sort of the standard you know movies like the use forty eight kilohertz and then you can use ninety six or one eight to keep going keep going higher and then but you're still going if you zoom in far enough you will still just have this sort of look at bay salt live but it's playing so fast that I really can't tell anyway but it's kind of important to know about that s o before I talk about bit death does anyone have any about all that we just talked about that we're good yeah I like explain that stuff it's just so good so bit death is kind of important for the most part playback wise it's not super super important is because you know you have sixteen twenty four but that's pretty much it but um in nfl and some other does there's actually a third option internally and that's also you can render as well and that's the thirty two bit wait file that's not thirty two bit of sixty four bit in terms of exit six processing or whatever it's thirty two bit depth bit depth is the measurement of how money sort of stops there are in volume volume reaction a good way to visualize this would be with the wave shipper it's a little white lie and type of way to use the stairs mode here you go this is kind of what but a bit depth represents from whatever its lowest silence measurable level as to zero t be sort of the maximum standard how many different levels of volume can there be from from that make negative eighty two there um big crushers reduce this amount which is why a thousand way it does you know if you make something sound a bit it is referring to the fact that I had a bit depth which wasn't super single again and there was other you know qualifiers too that existence but this is about that's what that means sixteen bit really the way the bits work it's a kind of a math but I'm not super familiar with anybody who's ever had any thank you peter sounds science will know that the difference between sixteen and twenty four but it is not a linear relationship it's one where the amount of stops in sixteen bit is a lot already the united stops in twenty four bit is allow more than just the fact twenty four is more than sixteen is numeral leans large amount and the whole point of this is that it increases the possibility for dynamic range which is the idea that we could have a quiet they could swell up and down and then that swell will not be jagged ian stupid sounding because we have enough stops the volume for it to interpret a level of volume for each of the visual moment in the sweeps okun go from pretty quiet to pray aloud and that you know break things thirty two bit is insanely more than that and the functional difference between thirty to be first twenty four events is that twenty four percent sixteen but um they stop at zero t b that's kind of their limit and you know for playback purposes that's everything you know every threes flax you know that kind of thing every everything plays back and stays in zero t b and it's pretty much but thirty but keeps going it doesn't actually stop a charity it has the same kind of density of measurement from the negative infinity to zero t b but then it just keeps going and the importance of this is the idea of that way look at like the mixer nfl studio for double um if I had a signal in somewhere other than the master right now it's not clipping but I could make a clip so right now that channel is going above zero debate that's going about zero t b is going into the master and if this were a purely sixteen twenty four bit world what that one means that it's clipping and I've lost that data that went above it created those perfect distorted square away is that much earlier but because it's going to thirty two bit somebody who had trust on the matter once told me that the limit to thirty two bit is something like a plus sixteen hundred tv some stupidly hi I'm out that he would never regional issue actively tried to and even then some dogs might not even by you it's because but um the purpose of this is that you really need to worry about things like like you know we look at you something you talk to mastering engineers tell you stuff like you know okay the kid needs to be a minus sixty being the middle is going to be a minus eight bb and like everything needs to be in all these particular levels and all the need to add up to be less than zero t me so that when they master it no that clipping that kind of thing but for thirty two bit and internally anyway it doesn't matter at all it matters only for your own listening sensibilities where things are the mixed sounds good you know and awarded out measurement even until the very end of your actual mastering chain where it goes out because chances are your playback even on the audio interfaces you're running even though this guy the playback is still twenty four bit for sixteen bet even if even if internally it's not clipping you're going to hear a clip but if you were to save it as a thirty foot file and you have peaks ago buzz already be those peaks still there they're not actually the store that I actually got, you could turn it down, and you could bring it below zero t b, and it'll be fine. It'll be its pristine, original self, and along with that, you can bring the noise for down further than anyone could possibly think about because of the whole sixteen hundred tv headroom, which one day I'll have to do an experiment to actually see that is what I'm talking about. But for the most part, people tend to stick around the whole zero g b limit because that's, the standard that's sort of how that works for playback of sixteen twenty four bad, literally everything else. There are thirty two bit interfaces I no idea how they work. I have to imagine they're really fun because I like things loud, I was the most of humans turns out, actually, there is the whole psychological concert of the fact that loudness, even if it's the same sound, you will think it sounds better like your brain, billy that's better, whatever that is, I like that better even don't say the same thing, just louder doesn't particularly matter much now, all of that, it was a nice primaries as the how digital, any saying works, which is cool to keep in mind, especially when we start talking about whatever kind of said this is we're doing versus the analog versions and a lot of people looking to get in their heads that we just cannot match the fidelity of analog anything and that's just not true, we might not be able to get exactly it's sort of identical to some certain things, but you wouldn't really get exactly identical in certain digital things, either, so don't worry about that too much don't worry about that too much because I use words, I promise. So now let's actually finally started for real talk about subtracted synthesis. The only weird this is that when you actually use the way of paper with the steps to do that, it doesn't sound like that crushing, as we expected to, because, you know, bit crushing the facts and the like enviously versions, or even like in plug ins, they do that, but they do it with different kinds of like shaping and different algorithms to make it not sound painful because it will if you deal with the waiver, which I guess does not, which I prefer, honestly, that it just does what's showing that's doing.