 Hey, it's Anfa and you're watching Anfa Vlog. Today I want to talk about the basics of dynamic range compression. If you don't know what a compressor is, how to use it and what it does, this is a video for you. So a dynamic range compressor is a device that helps us control the volume changes inside sound recordings. So basically when you have something very quiet and then suddenly something very loud, usually that's not a good thing. You need to level that out. You need to make the quieter things louder and the louder things quieter to even out the level so the listener will be able to hear the quiet stuff and not be blown away by the loud stuff. And that is exactly why a compressor is called a compressor because it compresses, thus reduces the differences in sound volume or loudness. So normally you could do this manually by using something called automation, which is basically drawing functions that will change some parameters inside your DAW over time. For example loudness. In the good old days, when tape recorders were a thing, you could basically have a mixer and play out something from one tape reel and record it to another tape reel and just grab a fader or a gain control on an ob and just move this up and down. As you listen to the sound, trying to level out the loudness, so someone's moving quiet, you're making this more louder to make it more louder, they make it more understandable then he's going loud so you're turning it down. So it's not so loud, right? You do this manually, riding the fader, that's what it's called. However, that's very tedious and if you have multiple tracks, for example you're recording a rock band and you have drums, just the drums take up a few tracks and everything plays and you have hours of audio material to just play through and ride the fader. And also you can't do it very precisely, you only can do it so fast. So if someone plays drums and you want to be so fast to make the impact of the snare, the transient, quieter, but you want to make the tail ring out more, so instead of having like a tch, have something like a tch, you know, tch, or tch, you can do this kind of stuff with compressors, but without compressors, how do you do it? You can't be so fast and precise with the faders. So the compressor was bored. Fader is basically a device that listens to the audio signal coming in and it has some settings determining when to turn things down. Compressor turns things down, that's the basic principle. You might have heard that compressors are either used to make things louder and that is because once you turn down the loud stuff, you can turn up the volume on everything and the quieter things effectively get louder when the loud stuff remains the same. For example, if you set up your compressor to react here and your quiet stuff is over there and then someone's shouting and he's over here, then the compressor will turn him down so that he's roughly, you know, on this level instead of this level, right? So you have that's, this is your threshold, right? You say compressor, compress these things when they cross this threshold and the things are sounding here. So it's below the threshold, then the things are sounding there because it's so loud and the compressor goes turning it down. Actually, I did it in the wrong wrong side because you see it in the mirror. So compressor goes and the sound go quiet. But then the input sound goes again, it going quieter. So the compressor goes turn it up again because it's falling below the threshold. So that's quite an analogy. The compressor is an automated process that listens to the sound and decides when to turn it down and how much based on how loud the thing is. It doesn't turn down everything. It only turns down things that are louder than what you tell it to. And then you can tweak the things. You can say how hard it has to turn things down. For example, when you have the threshold at negative 20 decibels, when something goes up to negative 10, so it's 10 decibels louder than the threshold, how loud should it be turned down? You can use a ratio control for that. So ratio tells you what is the ratio of the turned down sound to the non-turned down sound when it crosses the threshold. So when you have 10 decibels above the threshold, that's the sound at the input, and you have ratio 2 to 1, that means it's going to be turned down so it's only 5 decibels above the threshold. When compressor will say, all right, that's enough. Ratio 2 to 1 says this is enough of compression. If you say 4 to 1, it's going to turn it down as much as it needs to make it just 2.5 decibels above the threshold, because 10 divided by 4 is 2.5. So right, you know, you have X to 1, which means X times quieter than what it was before relative to the threshold. Confused! Okay, so that's, I guess that's enough theory for one chunk. Let's jump into Ardor and I will show you how it works. So here is my Ardor session. I will add one track and I will record some voice. Quiet, quiet, quiet, quiet, loud, loud, quiet, quiet, quiet, quiet. Right, so we have a material, we have quiet parts and we have loud parts and as you probably can hear, quiet, quiet, quiet, loud, loud. The quiet parts are so quiet we can barely hear them on the recording. So we can use a compressor to bring down the loud parts and then bring up the whole thing so we level out the differences between the quiet and the loud. That's where compressors are mainly for. So I'm going to add a Culp Compressor and you can see it reacts to my voice. If I play it, please stay on top. As you can see, nothing really changed because our sound never hit the threshold, right? So again, the most fundamental controls of the compressor are threshold and ratio. The threshold is where the thing starts to compress. Right now it's going to start to compress earlier. If I move it up, it's going to start to compress later. So let's play this out in loop and we're just going to play around with settings. The turn down, so I've turned down the threshold to make it react to the louder parts. Now if I make the ratio higher, I'm doing even more compression. I can go all the way up. This is basically a brick wall limiter right now. And now if I turn up the make up gain, everything is louder, however the louder parts are relatively less loud than they were before. And this is what we want. This is basically what you're using compressors for. So what are the different settings? We have attack and release. Attack is the time that the compressor takes to turn the things down after they cross the threshold for the first time. For example, if I turn this time up and play this, you see that we don't really have a lot of compression going on. This is very loud. If I turn the attack time lower, like 200 milliseconds, let's play it again. It's kind of reacting but with a slight delay. And remember, this is not like the compressor is sleeping for 500 milliseconds or something and then oh shit and turns it all the way down. No, it's starting right when the sound crosses the threshold but it's taking slower turns when you have a higher attack. And this graph here represents all of that. And it's very helpful because it shows you the input level and the output curve, like the function. What is happening to our loudness? This is exactly what is happening. This meter here shows us the gain reduction. So how much we're turning things down right now? Quiet, quiet, quiet, quiet. No gain reduction means we're not turning down the quiet part at all. And then the loud part comes in, loud, loud. And we're going like negative three, negative five decibels of gain reduction. Negative six decibels is about twice as quiet. So five decibels is almost that. It's quite a lot. However, we have huge differences in volume in this recording so it's not a big deal. It's actually what we need. We need big changes. There is also a parameter called knee and that smooths out the transition between the not compressed function and the compressed function. So you can see if I turn down the knee, we have a very sharp transition between the not compressed part and the compressed part. And usually it's not very much audible, but it makes the compression a little bit less gentle. It's not happening so aggressively. So I guess it's okay to have a little bit of that. Many compressors don't have a knob for this setting, but they have something like hard knee or soft knee. So they just have an on off switch, like two states. The cough compressor has a lot of control and this is why I like it. And also it has this nice function graph that shows you what is happening to your sound and what the compressor is doing and how it will react. And that's very helpful in understanding how it works. That's why I like it a lot. All right. Quiet, quiet, quiet, quiet, loud, loud. Can we turn this down more? Well, we can. If I turn the attack lower, we have almost instantaneous reaction. Let's hear it. Quiet, quiet, quiet, quiet, loud, loud. You can see I didn't change anything. I didn't touch the threshold or the ratio just the attack time. And we've got like four times the amount of compression happening because the compressor had the time or it was fast enough to turn it down all the way where it wanted. And that's quite a lot. Quiet, quiet, quiet, quiet, loud, almost 14 decibels of gain reduction. That's a lot. Now there is release time. So attack time is how fast the compressor will turn things down. Release time is the opposite. It's how fast the compressor will turn things up again when the input level drops. So if I make the release time very, very long, the maximum value here is two seconds. Let's play the quiet part and sorry, let's play the loud part and then the quiet part and listen. Loud, quiet, quiet, quiet, quiet. Now if I turn the release down loud, quiet, quiet, quiet, quiet. Because I have the attack and release time so short, it actually distorts the signal. So I have to make it a little bit higher, loud, quiet, quiet, quiet. We have still a little bit of distortion, loud, quiet, quiet, quiet, quiet. You can hear that this first part, quiet, quiet, quiet, quiet is actually louder now if I turn the release up to two seconds, loud, quiet, quiet, quiet, quiet. We still have gain reduction up here. You can see the gain reduction meter as it goes down. Take a look at it loud, quiet, quiet, quiet, quiet. We still had quite a lot of gain reduction even though this input level dropped way below the threshold. So the compressor should not be doing anything then. Because of the high release time, it was turning things up but it took it way too long to be fast enough. Well put. So yeah, ratio, how hard you compress, threshold, when you compress, attack, how fast you turn things down, release, how fast you turn things up, knee, how hard is the transition from not compressed to compressed and make up gain, how much louder you make it after the compression happens. That's the basic controls for a compressor. I'm gonna leave you with that. Feel free to experiment, record some stuff, drop compressors on, turn the knobs, listen to what it does, figure out this tool. It's very important. It's one of the most ubiquitous tools in music production and sound engineering at all. Compressors are very, very needed. So I will make another video about compression. I'm going to talk about different types of compression. We're gonna talk about sidechain compression, multi-band compression, de-assing, limiting, and the like. But this would be too much for this one video so I'm gonna cut it here and if you want to know more about compression or open source music production in general, tune in for the next time. So thanks for watching. I hope you've learned something. If you have any questions or suggestions, please leave them in the comments. If you want to support me, you can buy my album on Bandcamp which was produced 100% with open source software and Linux and it's eclectic electronic dance music, blending different types, also some male vocals if you like that, but not all of them. Just tiny bit of them. And I think it's really kickass music. You can also support me by becoming a patron on patreon.com for just as little as $1 a month. You can drop me $1 a month and that will enable me to dedicate more time to making videos like this and less time to do other things like graphic design which is what I do for living right now. With Glendor and Linux and open source software too, but still it takes me quite a lot of time. So I'm not providing any downloads for this episode because basically this session is just my one track with one clip so you can record your own. Yep, thanks for watching and I will see you in the next video. Bye!