Processing vocals with compression and limiting - Logic Pro Tutorial

- [Instructor] While equalization allows us to work with the frequency range, compression allows us to work with the dynamic range of a voice. What is dynamic range? It's the range between loud and soft volume of a recorded sound. It turns out a human voice is one of the most dynamic instruments we'll encounter in recording, moving wildly from too loud to too quiet, even in the course of one phrase of a verse. Because of this, we almost always rely on compression as a tool to help tame and narrow the dynamic range so we can make a vocalist's level sit more solidly in a mix with other instruments. So the first question we want to ask is do we EQ or compress first? There really is no right or wrong answer to this. How does it sound is the real answer. Just be aware that some compressors add tonal color, so if you EQ after the compressor, you can take that into account as you work. One technique I like to do, is to do my low cut, or high-pass filter, before the compressor, so in other words, my first plug-in slot will be an EQ that just takes care of the low frequencies. Then, I'll insert my compressor after that, and then after the compressor, I'll insert my tonal shaping EQ. So that's one way to work, it's the way I like to work depending on the song, but you can figure out which one you like better, whether you EQ or compress first. So I'm gonna put the compressor right in between the high-pass filter and my tonal shaping EQ. Now, Logic has one of my favorite compressors out there, it's just the generic compressor that now comes with Logic Pro 10. And this is an awesome compressor, there's many different variations you can do with the compressor, many different styles of compression you can do, and for vocals, for this time, I'm gonna try the vintage VCA. This is an SSL-type compressor, I find it works really well on Jade's voice, so I'm gonna try this. I also like the amount of control I have with the settings here. So here's a good guide on how to approach local compression and I'll use this vintage VCA to demonstrate this. Now remember, a lot of compressors have these types of setting. You'll see threshold, ratio, attack, release, make up, gain, other compressor styles, this is cool 'cause I can actually show you. Other compressor styles, like classic VCA, don't have as much possibilities in terms of setting the attack and release values, so every compressor will have its own nuances, but this is a good place to start since it has most of the parameters we might look at. So the place to start is you want to start with a fast attack. This might not be where the knob ends up, but it allows you to instantly hear the compression as it happens, so you really know what the compression is doing to the vocal. And, again, I start fast here, and then I'll probably back this off later, but it gives you a good insight into what's happening if you set that to fast to begin with. Next, we'll make our ratio four to one. Four to one is about as high as you'd set your ratio for any vocals, so again, starting at the top here, we can hear what it's really doing, and then we can back it off a little bit if we need to. The next thing we want to do is play the music, or play the vocal, and we'll lower our threshold. We'll start with the threshold all the way up, so in other words, nothing is being compressed. Remember, the threshold is the point at which the compressor starts working, and then when I wanna do is lower the threshold until just the loudest sections start to become compressed. How do we know they're becoming compressed? Well, we're gonna be looking at this meter and we'll see gain reduction. This meter is actually gain reduction, so it starts at zero and when gain starts to get reduced, or the signal becomes compressed, this meter will move in the negative direction. So, what we want, ideally, is the louder sections of the vocal to activate this needle, the quieter sections won't activate the needle, and that's where we're optimally set our threshold value. So I'm gonna go ahead and hit play. Now I wanna do one thing, before I hit play, Logic sets it up to have auto-gain on, we want to actually turn that off. So it automatically is doing an automatic gain makeup on the compressor, which I don't like, I like to do the makeup my own, so this knob will come into play as soon as I turn auto-gain off. I wish that wasn't the default setting, but it is, so we're gonna turn that off. So now I'm gonna hit play and move the threshold down until the louder sections start to activate. So if I go too far, it's compressing the whole signal, we don't want that, right? Start all the way up here and just move it down. (vocal music) Somewhere around (vocal music) I think 17 or 18 is a good spot. That's a quiet section, it didn't move it. And that's a louder section, it starts moving the needle. At the end of the phrases, when it goes, "Waiting for you," at the very end of that phrase is not moving the needle while the beginning of the phrases are activating the needle so that's a good spot for your threshold. Again, you're trying to tame the louder sections and you're trying to leave the quieter sections alone. So it looks like in this case about minus 18 is a good spot for our threshold. Next, we're gonna start looking at this attack knob, now it's very grabby, it's grabbing on right away to everything, and for a vocal, what that results in is you start to hear the compression. Again, just like I mentioned with EQ, you don't want to hear the EQ, you just want to have a natural sounding voice, same goes with compression. You don't want to hear the compression, you just want the voice to work better in the mix. This isn't a compressor use where we're trying to create an effect, which you can very much do with a compressor, but in this case, we're trying to use it as a mix tool to help tame some of the louder sections of the vocal and ultimately to make the quieter sections louder. By backing off the attack knob, making it a little slower, we'll start to hear the compression a little less although it'll still be working, hopefully, on the vocals. Let's hear what this sounds like. (vocal music) Okay, we'll just go a little bit faster, there we go. (vocal music) Okay, so we're doing a bit of gain reduction, not too much. It probably goes up to minus four at the maximum, and we're achieving our purpose of taming the louder sections while we're leaving the quieter sections alone. But because we're doing compression, we wanna make up for that lost gain that we're compressing, so we're gonna use our makeup gain knob and I'm gonna push this up about four decibels, and that'll make up for the amount that we're taking off of the louder sections, but it'll also bring the quieter sections up four decibels, so, again, we're narrowing the dynamic range and this will allow the vocal to sit better in the mix. Let's take a listen. (vocal music) That's great, I still wanna get a little bit more out of those loud sections, so I'm gonna pull down the threshold another couple of decibels, and let's hear how this sounds. (vocal music) So, hear how the ends of the phrases, "the moon and pull it down", that part, before, that was getting a little lost. Let me take out the compressor, and especially listen to the end of the phrases. So, here we go. (vocal music) See how that gets buried in there? Once you put the compressor in, it's really no louder overall, but everything is being able to sit on top of the mix, especially the ends of the phrases. (vocal music) You're getting all of that nuance of all the phrases just by applying a pretty subtle amount of compression but just grabbing those louder things, bringing everything up a little bit. Now another way you can kind of check your work is if you look that the input gain meter, and then you look at the output gain meter, this meter shows the signal before the signal comes into the compressor, and this is after compression. So if you look at the input gain meter over the course of this passage, you'll notice the levels are moving pretty wildly, and then if you look at the output gain, you'll see that they're pretty much staying in a very much narrower range, so we're doing our job, we're narrowing the dynamic range. Take a look at the input gain meter. (vocal music) It's going all the way up to here and sometimes all the way down here. And the output gain, I'll play that section again, you notice it all hovers around the same area. (vocal music) So everything, for the most part, is centering between minus 12 and minus 9. Now, there were a couple peaky sections, and a lot of times, I'll end up putting a limiter after our compressor just to grab anything stray, anything that just kind of gets through the threshold of the compressor, we'll do a limiter. And all a limiter is is a high ratio compressor, so it's the equivalent of having this ratio really high, so it's almost like a brick wall, it doesn't let things through. So we're gonna be a lot more timid with our threshold for the limiter, we're only gonna put it, in this case, probably around minus 10 at the most, maybe minus 8, even. Where our threshold was much lower for our compressor since that's a gentler gain reduction, the threshold is pretty severe, but we're only looking to grab those peak moments, and so, let's see, if I put this in around minus 8, let's see what that sounds like. (vocal music) Well, it's really reigning everything in, especially if you're looking at this meter here. (vocal music) Everything is hovering around this range, whereas in the input it's going as high as here, and low as here, making it much more difficult to mix in the song. So now that we have this compression set up and this limiter set up, we're gonna have a much easier time hearing all the subtle nuances, all the good stuff that Jade did in her vocal by using this compression. It's gonna come out in the mix, and it's gonna allow us to set our fader in a specific spot and really keep it in that range so we can hear the vocal throughout the song.