How To Use Parallel Compression Like A Pro

Download Your Free Compression Cheatsheet
Keep watching to learn how to use parallel compression like a pro.

Hey, this is Jason from Behind the Speakers. And in this video, you’ll learn what parallel compression is, what it’s good for, and how to use it in your mixes. But before we dive in, make sure you grab my free compression cheatsheet first by clicking the link above or in the description below.

So first of all, what is parallel compression? Let’s take a look at this session that I have here. This is a track called “Everything Gets Old” by Dylan Owen, and I just have the drums from that song here. So you can see there’s a bunch of different tracks – we have a couple kicks, some snares, hi-hats, etc. – and I’ve routed all of those drums so they’re all being sent into this rhythm aux track. So you can see the input of this is rhythm, and all these individual tracks are routed out into that rhythm aux track. So all the drums are being sent here. Now I can control those drums with one fader right at the spot.

Now let’s say I wanted to add some compression to these drums. Well there are two different ways that I could do this. The easiest and most common approach would be just to go up to this drum aux track here and add a compressor across the entire group of drums right in line with the drum track itself. So this is what’s called serial compression, and it’s the normal form of compression that everybody thinks of when they think of compression – just adding a compressor directly onto the track that you’re compressing.

Now on the flip side, another approach would be, let’s say I duplicate this track. So now I have two versions of this aux track, two copies essentially of the drums. And I could add a compressor on one of them, but leave the other dry. So now I have two copies of my drum tracks – one version of the drums has no compression on it, and one version of the drums has compression on it. And I can blend the compressed version in alongside the original, or in parallel with the original.

So this is parallel compression. We’re using a copy of the sound. We’re compressing that, and then we’re blending that compressed version under the original sound. So at this point, you might be thinking well this seems a lot more complicated than normal serial compression. Why would I use parallel compression? Why not just use the simpler approach? That’s a good question. Because the truth is in most circumstances, normal serial compression is fine, and I don’t actually find myself using parallel compression all that often in my mixing process.

But here’s the thing about parallel compression. Here’s where I find it’s very useful. When you have a track that you really like the sound of the track and you don’t want to change that sound dramatically, but you just want to add a little bit of something to that track, something that’s missing, that’s when parallel compression is really useful. Because a lot of the time when we add compression to a track, the sound of the track changes pretty significantly. And sometimes this is fine, but sometimes if we like the way the track sounds in the beginning, we don’t want this. So I find parallel compression to be a more subtle way of enhancing a track, because we’re retaining the original character of the sound and just blending in a little bit of what we want more of.

Now most people think about parallel compression as just one technique. But there are actually a couple different ways that you can approach it that will lead to dramatically different results.

So what I have set up here is I have my rhythm track. I’m just going to delete this duplicate that I added. So I have my drums being sent into this rhythm aux track, and then I have a number of parallel tracks. So what I’ve done is I’ve duplicated this rhythm track three times and just relabeled them, and what I want to do here is show you a couple different ways to approach applying parallel compression.

So first, let’s just take a listen to the rhythm tracks dry. So this is just the dry tracks, no compression added.

Okay, so taking that mindset of parallel compression as a tool we can use to add something to a sound, the question I want to ask myself when I’m applying parallel compression is what’s missing from this original sound? What might I want to add to it? And there are a couple different answers that I could come up with.

So let’s say we’re listening to those drums and we say hey, you know, I really liked the punch and the impact of those drums, but I just feel like what I want a little bit more of is the tail end of those sounds, the sustain or the decay – those low-level details where the snare hits and it kind of rings out a little bit. I want more of that energy. And in this case, we might use this first approach. So let’s take a look at the compressor here.

So I’ve added a compressor to this track, and I’ve set this compressor up with a very fast attack time and a release time that’s pretty fast. And I’ve also used a high ratio, and I’m applying quite a bit of compression. So higher ratios are pretty normal with parallel compression because in general we’re going for a fairly aggressive sound, because this is not the only thing that we’re hearing, right? We’re blending this in under the original. So we’re kind of overdoing it on the parallel compressed track, and then just blending it in so that it doesn’t sound so aggressive when it’s in parallel with the original.

Now a fast attack time is going to tell the compressor to react immediately after the sound hits. So right at the beginning of that snare hit, right where that punch and that impact is, that compressor’s going to grab that sound and turn it down. And so what happens is a fast attack time actually turns down the initial punch and impact right at the beginning of the sounds.

Now a fast release time is going to tell the compressor to let go very quickly after it does that. So what happens is the compressor hears that initial punch or impact right at the beginning of the sound, it turns it down, and then it lets go very quickly. And what’s left is the decay, or the sustain, the tail of the hits. So what we’re doing is we’re telling this compressor to turn down the punch and leave the other stuff, so what we’re left with is the sustain or decay. So let’s take a listen to this on its own.

So it’s not a particularly pleasant sound, right? It’s a little bit distorted. But you can hear we’re actually not hearing a lot of that punch or impact. We’re hearing a lot of the sustain or decay. So we’ve used this compressor to basically take away the stuff that we don’t want to add more of and leave the stuff that we do want to have more of. So now we can blend this in under the original drums, and it’s almost like this track is like a sustain control. We can bring in more decay and sustain by just turning up this fader. So next I’m going to listen to the dry track, and I’m going to blend this in under the original dry track until I feel like I’m getting the sound that we’re looking for.

Okay so let’s take a listen before and after.

Okay, so obviously it’s a little bit louder, but what I’m hearing is more of that decay, right? We’re hearing more of the ring on the snare. The kick feels like it’s longer. It just feels like it decays a bit more slowly over time. So this is the first way to approach parallel compression using it as a tool to bring up some of those lower-level details, the decay and the ring on parts.

Okay, so the next approach we could use is let’s say we’re listening to those drums and we think well you know, I really like the decay on the drums. I don’t feel like there needs to be any more of that. But what I feel like I’m missing is I feel like I’m missing the punch or the impact on the beginning of the hits. I want more of that. So let’s take a look at this track here. This is the second approach. And in this case, we have the same ratio, the same threshold, so we’re applying basically the same amount of compression. But we have a slow attack time, and a slow release time.

And what this is going to tell the compressor to do is actually to bring out the punch or the impact right at the beginning of those hits. So this is like the opposite approach as the last compressor that we saw.

So let’s take a listen to this.

So you can hear we hear all that thwack and punch right at the beginning of those hits. So in this case, we’re actually setting up this compressor so that it turns down the sustain or the decay, and leaves or actually accentuates the punch and impact at the beginning of the hits.

So let’s blend this in with the original and take a listen to the result that we get.

Okay, before and after.

So now what we’re hearing is more of the front end of those drums, right? We hear more punch and impact at the beginning of the hits. So very different approach from the first parallel compression.

The next approach and the last approach I want to show you here is kind of a hybrid of these two. So let’s say we want to bring up both the punch and the decay on the tail ends of the hits. So in this case, we have a slower attack time, but we have a bit of a faster release time. And that fast release time is actually going to cause the compressor to bring up a lot more of the tail end of the hits, right?

So in the compressed version before we had a slow release time, and in this case we have a faster release time. So that’s what’s causing this compressor to bring up the low-level details, but we still have a slow attack time, so we’re still bringing out the punch as well.

So take a listen to this.

So in this case, we can hear both the punch at the beginning of the drum hits, and we can also hear a lot of that sustain. So let’s take a listen to this, and we’re going to blend it in under the original.

Before and after.

So again, it’s a little bit difficult with the volume change, but you can hear we’re just hearing more of that punch but we’re also getting some decay and sustain as well. Now the message I want to share with you here is essentially that these are three very different ways to approach parallel compression, and they might all work for different circumstances. So really what you want to be asking yourself when you’re using parallel compression is what do I want to add to the original sound? Do I want to add punch? Do I want to add decay? Or do I want a little bit of both? And that’s going to help you determine which of these three approaches you use.

Now the last thing I want to show you, and this is a little bit of a kind of bonus tip, is that what you can do on the parallel compressed track is you can actually add some additional processing on this track. So you don’t just have to add compression. So in this case, what I’m going to do is add some EQ. And I’m going to use this EQ to bring up some of the extremes of the frequency spectrum. So I’m going to bring up some low end, bring up some high end, and then I’m going to apply a little bit of a dip in the midrange. So now we have kind of a scooped sound.

So let me take a listen to this on its own and kind of dial this in.

Okay, so that sounds a little bit extreme on its own, but by blending that in under the original, we can actually add more energy and height to the drums themselves. It’s just a way to make them sparkle a little bit more. So take a listen.

Okay, so I’m going to play this, and I’m going to flip this EQ in and out now. And notice the drums just sound a bit larger and more – there’s just this kind of bigger quality to them with this EQ engaged.

It’s subtle, but they do really sound a bit more three-dimensional with that EQ engaged. So don’t be afraid to add additional processing to your parallel compressed track. You don’t just have to add compression alone.

Okay, so I hope you found this helpful. And again, if you want to dive deeper, one of the things I recommend you do is go download my free compression cheatsheet. Click the link above or in the description below to do that, and this cheatsheet’s going to give you some additional tips for working with compression so that you can make the most of it in your mixing process.

Now before you go, leave a comment below this video and let me know – have you ever used parallel compression in your mixing process before? I’d love to hear your replies, so leave your answer in the comments section below.

And for more mixing tips and videos like these, check out my YouTube channel right here or go to BehindTheSpeakers.com.

About Jason Moss

Jason is an LA-based mixer and the founder of Behind The Speakers. He's a graduate of New York University's Clive Davis Institute of Recorded Music. His how-to articles have been featured in leading industry publications by Berklee, TuneCore, SonicScoop, The Pro Audio Files, and Disc Makers.