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How to Record: Compression Plugins (Lesson 10)

Hi, it’s Warren Huart here. Hope you’re doing marvelously well. And I just realized, this is the first time we’ve ever shot a video in the evening, so it’s a little different here. Obviously, there’s no daylight coming through, which is beautiful during the day to have that daylight, but here we are at night.

Now, in lesson ten today, we’re going to — or tonight — we’re going to talk about compression. That’s a big discussion, and we could probably do several videos on different ways to use compressors, and the why you use them and the where you use them, and all the different things they can do.

Um, we’re going to stick in — we’ll stick in the world of digital, because it’ll be so much easier to move quickly between there, and I’ll show you all the different compressors that I use and how I use them, and I’ll tell you why.

Now, traditionally, compressors were designed to control the dynamic range of a signal. Now, for those of you that don’t understand what I mean, that is how loud it gets and how quiet it gets, because you know, if you’re playing with a — if you’re using a very dynamic instrument, to be honest, such as the human voice, if someone is maybe singing like this, and then suddenly, you know, it gets really super loud, if you just print without a compressor, you might peak and distort, and then other moments, it might be barely audible.

You know, younger singers and less experienced singers tend to have very, very large dynamic ranges. They tend to go very loud to very quiet, and everywhere in between, so what a compressor does is it allows us to print a hotter signal.

The reason why we can print a hotter signal is we can take the peaks and we tame them down a little bit so you can get a little bit more output, so that way, the softer parts, instead of being down here, maybe here, and the high peaks may be there, instead of being there, or about here, so the dynamic range is limited a little tiny bit.

So a compressor will reduce the dynamic range, allowing us to print a hotter signal. Now, the way a compressor works, and there are several different hardware compressors — quite a few different hardware compressors — some are — well, they’re essentially voltage control amplifiers. VCAs, you’ll hear that a lot. What that will do is it’s literally like riding a volume control.

So when you get to a certain level above zero dB, it will turn it down the same amount. So let’s look at some basic compressors, I’ll explain how they work, and we’ll try them on different instruments so you can hear them and see what they do.

Okay, so let’s go to our session. It’s the Love Me, I’m Rich session we’ve been using quite a lot so you can get your ear used to it, and let’s look at some different instruments.

Okay, so let’s look at a vocal. Let’s take a little section here. Um, let me find something. Okay, I’m going to go to this chorus here, only because you can see, there’s quite a big dynamic range. You’ve got some peaks here, you’ve got some quieter parts here. I’m going to turn off the compressor that’s on there at the moment, and I’m going to send this directly to the channel. I’m going to disengage the compression on the channel, because there’s a little bit of compression going on my SSL, and now, this is absolutely nothing on the vocal.

[vocals, raw]

Cool. So you can see, you know, there’s — it’s pretty dynamic. You know, she’s probably moving slightly around on the microphone. These are all things that singers will do. They’ll get really into the song, they’ll move their head, obviously, you want to try to keep them focused on the mic as much as possible, but at the same time, there’s only so much you can do.

And you know, you also want the passion, and sometimes, if they’re performing, and they’re moving their head a little bit and going a little off axis, it might not be the most perfect thing sonically, but it might be the best thing for the performance, and the performance is the most important thing.

Okay, so let’s have a look at some different compressions. If I go to my dynamics section here, I’ve got a lot of different compressors to try. I’m going to try my favorite analog channel. As you know, I’m a big fan of this. Okay, so let’s have a — let’s take just a little bit of the phrase that we can repeat. Okay, select gain reduction, see where it defaulted to.

[vocals, with compression]

So it’s not doing much there. We’ve got input volume, we’ve got compression. I still have a fixed threshold, which means because there’s no threshold control on it, like an 1176, which we’ll look at next, it has a fixed threshold, so that means it has a point where the compressor starts working. If it’s a variable threshold, you can move that down or up to the gain, but because it only has an input and a drive control, that basically — the input is going to turn you up until you hit the threshold, and then the compression will start, so let’s play with it.

[vocals, adjusting input gain]

Now, that’s overdriving, and to be honest, that’s kind of the sound of this analog channel, it kind of gives you that grit. So I’m going to take it back off, and what I’m going to do…


Is increase the compression amount, input a bit more, a little bit of drive.

Now you see, when I move that release control to one second, what that’s doing is deciding how long it’s going to hold on to the signal after the volume has actually decreased below the threshold. So if I turn it up like this and the signal goes above the threshold, it might duck down immediately, but that release, if it’s really slow, set to one second, which is like, very old compressors, like LA2As have really slow releases. Gates, compressors, a lot of those old tube compressors are very slow releases.

I can emulate that by putting it up there, however, I don’t personally like that on a — I don’t like that on a vocal, but you can hear what it does.

[vocals, compressed]

Let’s bring it all the way back to the left. It sits barely — it’s barely holding onto it. You can hear it kind of releasing quickly.

Now, with the attack…

[vocals, adjusting attack speed]

Full left hand side, here’s super short attack, which means basically how much it lets go through before it starts to grab it. How fast is it grabbing it? If I go full to the right…


Basically, it’s letting everything go through, because before it has a chance to get hold of it, the signal is already dropped, so let’s go full to the left and hear it again.

Turn it off. Now that’s a pretty gritty, I would say distorted sounding compression. What we’ve got, we’ve got the compression up to 6.5 here, it means it’s grabbing it pretty tough. I like this, and for this song, if you’ve never listened to it before, it’s a pretty gritty rock song.


It’s not a beautiful pop song, it’s got a little bit of grit to it, so I’d probably work with that. Let’s try a couple other different compressors. Let’s go to a good old fashioned 1176. So that’s the Bomb Factory that comes standard with Pro Tools. You’ll see where it defaults.

[vocals with Bomb Factory]

Now, as I was explaining, an 1176 is a fixed threshold compressor, so at the moment, it’s compressing pretty heavily almost immediately, so if I pull this down…

[vocals, adjusting input]

There’s a little less compression. But if you bypass it, you’ll notice the level is quite different, so let’s try and match it. It’s pretty close. Now, the way this release is setup, this 1 to 7 is really confusing. So, if I went to 1 like this, you’d think that would be the shortest release time. It’s not.

It’s back to front on 1176, it will always confuse you, it’s just a numeric system they have in there. It doesn’t mean 1 second to 7 seconds, it doesn’t mean 0.1, it actually means the reverse. So if I go to the full right…

[vocals, 7 release]

You see, it’s releasing it quicker. Let’s adjust our attack.

[adjusting attack on compressor]

Again, fastest to the right, slowest to the left, it’s back to front, I know. Now, the ratios here are four, to twenty to one. Now, a four to one means this. It will have to go four dB over zero before it lets one dB through. So that means, here’s our fixed threshold. If the signal gets to be four dB over, it will let one dB through. If I go to eight to one, once it goes eight dB over zero, it will let one dB through. If I go to twelve to one, it has to go twelve dB over, just to let one through. Then of course if I go to twenty, which is close to limiting, it has to go twenty dB over zero to let one dB through.

So twenty is kind of our limit. It’s our limiter, and four is kind of a softer compression. Now, I personally use the meter on gain reduction at all times. That’s where it defaults to, I like seeing and hearing what it’s doing.


Now, you know, it’s still gritty. It’s not as gritty as the Analog Channel, but then again, the Analog Channel is simulating analog distortion, and I love that, and tape, etcetera, but this one isn’t. I like it, the song is, you can hear it.


You know, it’s a rock song. We’ve used this before in other lessons. Okay, so let’s go to another compressor. Let’s go to the Analog Channel compressor bank. Another one of the McDSP ones. This one is very easy to figure out, because this is a variable threshold, not a fixed, if you’ll see.


You see this little triangle here? You know, I move the threshold, it gets more aggressive, and less aggressive, so if we do this…

[adjusting threshold]

Pull it down. So basically, you can see where the threshold is set. So every time it goes over, it will reduce the signal, and you’ll see it in the orange over here to the right.

[adjusting compressor threshold]

Okay, there’s an auto function on here where it will do the automatic attack and release for you, but let’s put the release to the fastest point. Adjust the attack. Wow, what a difference between there and there. Now we’ll even it out. What I like about that one, that last word, fun, it doesn’t seem to have the attack at the front, and the whole end is — this is a good compressor, I like these. It has a lot of level on the end of the phrase.



It doesn’t catch quite the end of that phrase, but it does enough to it to just kind of bring it up. Let’s now — let’s go to this next phrase here and hear it with and without compressor. Here’s without.

[vocals, no compressor]

Let’s bring it back on. So what that’s allowing us to do is we’ve got 3dB additional gain here, which is really helping it where the compressor isn’t catching those, and then it’s pulling down the rest of it here, so it’s kind of nice. Let’s try the SSL compressor. The channel one here. So let’s go to the SSL Channel.

This is basically a copy of what I have. I have an E-Channel on the console.

[vocals through SSL compressor]

Variable threshold here, let’s adjust. So I’ve got the ratio just set to two to one. Let’s go to like, three here.


That’s evening it out a lot more. The thing is, I don’t like to hear too much compression, so what I’ll do is I’ll use two or three compressors together. So let’s put our release to the fastest. Set our attack fast. Change the output. Without, bypassed. Put it back on.

So that’s pretty — that’s evening it out quite considerably, and I like the sound of it, and this is quite useful, because it’s got a lot of EQ, etcetera I can do to it. I can boost the top end here on a channel and really have some fun.

[vocals, adjusting SSL Channel]

It’s quite aggressive, but we can run a de-esser and stuff on it. So what I might do is run this compressor, say, for instance, and I don’t know, let’s go and put like — if I was recording for instance, I would probably go and put an 1176 across it, so let’s simulate that. Let’s go back to the Bomb Factory. Let’s set this to twenty to one. Set the release super fast.

[vocals, BF76, then full mix]

So you can hear a combination of compressors there. Now, if I send this back through my buss, you’ll hear all kinds of fun stuff that I’ve done. Okay, so solo the vocal. I’ve got an EQ lift here. So what I’ve got here is I’ve got a de-esser.

[vocals with de-esser]

An EQ doing a roll off, I’ve got a little boost on the McDSP here, I’ve got a compressor here. An R-Vox. I do like the R-Vox. It’s really dumb. You can just use it just to grab.

It’s got a fast enough release time that it fits in the track, so let’s put everything back in. All of the effects, etcetera, and see how it fits into the track.


So I’ve got harmonies there, I’ve got the lead vocal, it’s quite compressed, but it’s very aggressive, and it fits the fact — I’m compressing a lot harder than I might on an acoustic song, because this is a big rock song, and you can hear just how it’s fighting for room, you know?


So, compression there is our friend. I’m using several compressors in different amounts. I probably would just use the R-Vox on my main vocal here.


I find the R-Vox is pretty forgiving and a great all around fattening tool, it really fattens up the vocal. If you hear, if we listen to just the R-Vox on its own, you’ll hear what it does. Just put it out on the channel here.


Back on. It’s subtle, but I love it, and you can get a little bit more aggressive on it, if necessary. Let’s really go crazy.

[vocals, adjusting R-Vox]

I mean, you can hear the compressor working, but that’s a good sounding, quick, easy fix of a compressor. I really do find it quite useful. I’ve worked with a lot of mixers that use that.

Okay, so let’s try working these compressors on a different source. Now, what might be fun would be to take a bit of the drums… let’s take the overheads, believe it or not, and I’ll take a verse beat, and I’m going to select a Bomb Factory compressor. Here it is, 1176 emulation.

[overheads with BF76]

Let’s push the input. Already, kind of rooming it up a little bit. It’s helping — it’s hitting the snare, so it’s bringing the kick up. See? Release, the fastest time. Slow attack. Allowing a lot of the transients to go through. Before.

[overheads, no compression]

Kind of boring. Snare sounds good, but…

[overheads, compressed]

Now I’ve got like, a really cool, trashy room tone. What I would probably do from this is go and crush it a little harder. How about we just take an L1? The most basic limiter there is. The snare is still hitting at about 0.6. Let’s bring it down. Now the snare is pretty balanced.

We just made some really cool room mics out of an overhead. That could be a really cool drum sound just for that. What I’m going to do for shnits and shniggles, as they say, is I’m going to use another, essentially compressor, a de-esser, which is going to control — let’s have a listen.


So what I’m doing is I’m hitting the sidechain so it’s just allowing me to listen to the frequency.

[overheads, filtered]

And there, I’m getting mainly the hi-hat, so now what I’m going to do is attenuate, turn down, that frequency. Now let’s take it out and put it back into order. Listen to the hat. Controlling the hat just a little bit. Now I think what I’m going to do is I’m actually going to add a little tiny bit of EQ over the top of that for the heck of it.

Let’s do a nice FilterBank, a good sounding EQ like that, and…


You’ve seem me do this in the EQ one. Control that slope. Hi-hat. Dominance. Hi-hat sucked in a little bit.

So cool. So with a bit of compression, a limiter, and a de-esser, which is essentially just compressing that specific high frequency isolated, we have taken an overhead, and turned it into a really cool room sound.


If we want to have some real fun, we could select, I dunno, 50, 60, around about here. Boost it like crazy, and bring that kick to life.

So cool. There’s some fun with compression and a little bit of EQ for fun.

Okay, I think we’ve covered all of the basics that we can do with a compressor. The only thing we could maybe look at a little further is compression on the bass. I’ve heard this said quite a few times that — treat your bass guitar and your vocal in a similar way, and I agree with that.

I feel like for compressors, what will work on a vocal will also work on a bass. That means getting it so that it doesn’t have that [popping sounds]. You know, you have to get the attack controlled so it’s not just letting the attack note go through, because that’s horrible on the bass to just have that pang, pang. You want a nice, round, evenness.

So you could take some of your compression settings from the vocal and apply them to the bass and treat them in that kind of way. Otherwise, you know, the thing about compressors is you can really shape sounds, and you can also treat them like EQs.

You know, each compressor has a slightly different sound, and a slightly different frequency response. 1176s traditionally had some more grit to them, so they’re always good on guitars, and I like them near the end of a vocal chain when I’m recording.

There’s a great grit to them. Great on snare drums, great on guitars, and personally, I think they’re great on vocals. Dbx 160VUs, which I hear there’s one that’s been released now, a plugin version of it. It’s traditionally very fat and warm sounding, and I like them on your initial piece of compression, if you’re using multiple compressors.

Um, otherwise, I think we’re good. We’re covering most of the bases. As ever, please leave me some questions below. We’re also going to do a hardware compressor one. We’ll do that on the next lesson, and we’ll also compare some hardware to some software compressors and we’ll let you see what the differences are, and what you can really do.

As ever, please subscribe, go to and sign up for the email list, and you’ll be able to see — you know, get all the different files that we have for download, go to our Vimeo account, and also enter all of the lovely competitions we do. So thank you ever so much for watching!


Warren Huart

Warren Huart

Warren Huart is an English record producer/musician/composer and recording engineer based in Los Angeles, California. Learn more at

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