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Sidechain Compression: How To Use It Like A Pro (Today!)

Download Your Free Sidechain Compression Cheatsheet
In this video, you’ll learn how to use sidechain compression like a pro.

Hey, this is Jason from Behind The Speakers, and before we dive in make sure you download my free sidechain compression cheatsheet which includes some additional tips and tricks I won’t be covering in this video. Click the link above or in the description below to download this free cheatsheet right now.

So first of all, what is sidechain compression? Well let’s take a look at normal compression first. Let’s say we want to apply normal compression to a bass track in our mix. So we add a compressor plug-in to that bass track, and we basically tell the compressor – hey look, listen to the sound of the bass, and whenever the bass gets too loud I want you to compress – I want you to turn it down. So the compressor plug-in listens to the sound of the bass, and whenever it gets too loud it reacts by turning the bass track down.

Sidechain compression is a little bit different. Instead of telling the compressor plug-in I want you to listen to the sound of the bass and use the sound of the bass to make decisions about when to compress the bass, we say I want you to listen to another track in your mix. And instead of making decisions about when to compress just by listening to the sound of the bass, I want you to listen to the kick drum. And whenever that kick drum track gets too loud, I want you to compress the bass. So now we’re telling the compressor on the bass to react based on the sound of the kick drum. So the compressor is listening to something else in the mix and using that other track to make decisions about when to compress the bass.

So when should you use sidechain compression? Well there are really two purposes for sidechain compression. The first is to create an effect. If you’ve listened to a lot of EDM music or dance music you know the sound of that pumping bass, where it feels like the bass kind of pumps in time with the music, and that’s an effect that’s created by sidechain compression. So let me jump into my DAW now and show you exactly how to create this effect by using sidechain compression.

Okay, so I have a song here called “Falling Down The Rabbit Hole,” by Megan Cavallari, and I want to show you how to achieve that EDM-type pumping sound that you hear so often where the bass feels like it’s pumping in time with the track. So let’s take a listen to the full mix first, and then I will show you how to pull off this technique using sidechain compression.

So you can hear the bass is actually pumping in time with the music. So whenever the kick hits, the bass temporarily drops in volume. And then it ramps up to its original volume just before the next kick hits, and then it gets turned down again. So you get this kind of pumping sound that’s in time with the beat of the music.

So let’s take a look here. Now I have the bass track here and the kick track here, and we’ll zero in on this a little bit more closely and I’ll show you exactly how I’ve created this effect. So let’s take a look at the kick track first. Now you can see here on my kick track I’ve set up a send. So I’m sending a piece of this kick drum sound out bus 11. Now if we pull this bus, or this send up, you’ll notice that I’ve enabled this pre button here. So I’ve clicked that in. And basically what that does, it tells ProTools that I don’t want the level that’s being sent out this bus to be affected by the level of the fader on the track. So if I turn this kick drum up or turn it down using this fader right here, I don’t want the level that’s going out bus 11 to change at all.

And this is really important because let’s say you set your sidechain compression up, you get the sound working really well and everything’s pumping in exactly the way you want, and then towards the middle of the mix you decide oh I kind of want to turn the kick drum down 5 dB. Now if you don’t have that pre control enabled, it means that the level that’s going into your compressor is also going to drop by 5 dB. And so suddenly your sidechain compression, that pumping, that sound that you’ve created is going to change because you’re sending a different signal level into that compressor. So you want to make sure you avoid that by turning on this pre control. And different DAWs might phrase it slightly differently, but it’s usually a button you can find on the send in your specific DAW.

So let’s go over to the bass track now. Now I’ve added a compressor on this bass track, and I like using this plug-in Waves C1 for sidechain compression like this. You can really use any compressor. I like this because it gives me control over the different parameters, ratio, attack, and release, so it’s very flexible, and that allows me to manipulate the sidechain compression to create that effect that really is tightly timed to the music.

Now the important thing here is that whatever compressor plug-in you use has a sidechain input. So there are some plug-ins that allow you to route a sidechain into that compressor, and there are some that don’t. So you want to make sure that whatever plug-in you’re using has a sidechain input. Now depending on what DAW you’re using, you’ll find that in different places. But in ProTools you can see right here this little key is the sidechain input control. So you can see here I’ve set bus 11 on this sidechain input, and that’s the same bus that I’m sending out on the kick drum. So basically all I’m doing is routing this kick drum sound into this compressor. So now the compressor is able to listen to the sound of the kick drum and use that information to make decisions about when to compress this bass track.

Now the key here is I really want this compressor to turn down the bass whenever the kick hits, and then I want the compressor to let go right before the next kick drum hit. So I’m trying to time the behavior of the compressor so that it reacts musically to the bpm of the song. So I don’t want it to compress too long because then it’s not going to give me that pumping sound, and I don’t want it to just release too quickly because then it’s not going to give me that sound that I’m looking for either.

So the key parameter that you want to pay attention to is the release time. And what I like to do is I use the meter on the compressor, the gain reduction meter, to help me decide how to set this. And you’ll see in a second when we press play you’re going to see that whenever the compressor starts compressing we see that on the meter. And then we’re going to see that compressor compressing less and less and less and we’re going to see that meter return back to zero. And the key is we want to time the compressor so that right before we hit zero, the next kick drum hits. So we’re timing the release of the compressor so that it’s pumping in time with the music. So this will make a little more sense once I press play, but I want you to just watch the gain reduction meter and notice that it’s actually moving, it’s bouncing in time with the music.

So you can see that red control here is actually bouncing in time with the music. So it’s going back to zero right before that next kick drum hits. So if we set the release time too long, and play it again –

So you can see in this case, the red is actually not returning to zero before the next kick drum hits. The compressor’s staying compressed too long. That’s not what we’re looking for. Now on the other hand, if we set the release time too fast –

Now the compressor is actually releasing too quickly, and we don’t get that pumping sound that we’re looking for. So the key here is you really want to time that release time so that it’s pumping in time with the music. And you can use your compressor’s gain reduction meters to make that process really easy.

Now on the attack time side, I like setting as quick as possible. So whatever the fastest control is is usually going to be the best approach for this specific type of effect, because we want the compressor to pull down the bass immediately once the kick drum hits. So we don’t want there to be any delay. We don’t want the compressor to wait after the kick drum hits. We want it to pull that bass down right away, and that’s going to give us the effect we’re looking for.

Now in terms of how much to compress or how high you want to put the ratio or where you want to put the threshold, that’s really up to taste. So obviously a higher ratio and a lower threshold is going to mean more compression is applied, and that’s going to make the effect more aggressive. So you just want to play around with those controls until you get the amount of pumping that you’re looking for. So if you want things to be more aggressive, you turn down the threshold and turn up the ratio, and that’s going to make the compression more aggressive, which is going to give you more of an aggressive pumping and breathing effect. So let’s try that right now. So I’m going to turn up the ratio and turn down the threshold.

So you can hear that’s a much deeper pump, right? We almost feel like the bass disappears in the middle, right between those kick hits. So that’s much more aggressive than the original control or parameters that I’d set. So you really just want to play around with that and figure out whatever sounds best to your ears depending on the track that you’re working with. So this is really the key to creating that pumping, breathing sidechain compression EDM-type effect that you hear so commonly in today’s music.

The second purpose for using sidechain compression is to create clarity and separation between tracks. So this is a little bit more subtle than the first example that we saw, but basically we can use sidechain compression to help tracks fit together a little bit better. And when two things are competing for space in the mix, we can use sidechain compression to create more clarity and separation so that both of those tracks can be heard clearly in the mix. So let me jump into my DAW again and show you exactly how to pull this off by using sidechain compression.

Okay so we’re back in ProTools, and I have a song here called “There’s More To Life,” by Dylan Owen, and I want to show you the second approach to sidechain compression, which is much more subtle. And it’s more about creating clarity and separation between tracks in the mix. So let’s take a listen to this full mix first, and then I’ll dive in and show you exactly how I used this specific approach to add more clarity between two different tracks in this session.

♪ There’s more to life than never leaving your room and being sad ♪

♪ There’s more to life than all the pieces of your past ♪

♪ There’s more to life than growing up with nobody to follow but ♪

So one of the things that was challenging about this mix was I had a bunch of different drum loops and kick drum samples and things like that. There were a lot of low end tracks that were competing for space, and I had – for example – multiple drum loops here. You can see here there’s a break 1, break 2, so those are drum loops that each had individual kick drum sounds in them in addition to a kick drum sample. So the challenge was how do I make all of the kick drums in these different tracks work together so it’s not a boomy, muddy mess.

So what I ended up settling on was using sidechain compression to duck the kick drum out of one of the drum loops to create more clarity in the low end in this mix. And the way that I went about that was – let’s take a look here. So I’ve added a multi-band compressor to this drum loop track. Now the approach here is I didn’t want to duck the entire frequency spectrum of the track itself, I just wanted to pull out a very specific area, which is right around that 50 to 100 Hertz range, so right at the bottom end, the low end of this track. So this is a little bit gentler of an approach. And by using multi-band compression, instead of turning down the entire track, I could just turn down a little piece of the track when it was a problem. So this is a great approach if you want to be a little bit more subtle when you’re using sidechain compression, and you just want to turn down a very specific area of the frequency spectrum.

So you can see here I have a kick drum sample track, and I’ve sent that kick drum out bus 13. And then I’ve enabled that pre control which we talked about a little bit earlier, and then I’ve routed the input of this sidechain on this compressor as bus 13. So now we’re sending this kick drum into this multi-band compressor. And I’ve set this up so whenever that kick drum sample plays, I’m just turning down a little bit of this part, this specific area of the frequency spectrum on this drum break track.

So let’s take a listen, and I’ll show you exactly what’s going on so you can take a look at the metering here. And you’ll see that whenever the kick drum hits, this multi-band compressor is turning down this specific area of the frequency spectrum on this drum loop.

There’s not a whole lot going on here. It’s only three or four dB, so it’s fairly gentle. But I want to flip this in and out of bypass, and I want you to listen to the clarity, and just the overall presentation of the low end. And notice that – to my ears – when I bypass this multi-band compressor and this sidechain compression is not happening anymore, I feel like the low end just gets a little bit boomy and thicker in a way that I don’t really like. So let’s take a listen. First I’m going to bypass this, and then I’ll flip it in and out so you can hear the difference.

So it’s a subtle change certainly, but to my ears it sounds like the low end is just cleaner. It’s clearer with that sidechain compression enabled. And that’s because we’re getting rid of that kick drum, or at least some of that kick drum on this drum loop track. And so we’re getting more of the kick drum sound from that one kick drum sample, and in this case it just lead to a clearer, better sound in my opinion. So whenever you have a mix where there are two tracks competing and you’re trying to create clarity, I find this approach of using sidechain compression to just duck some energy out of one track when the other hits can be really useful. And in my experience it’s a great way to eliminate competition, especially in the low end. It just makes tracks fit together a whole lot better.

So there are a couple things you want to watch out for when you’re using sidechain compression. The first is distortion. So whenever your release time on your compressor is set too fast, you run the risk of adding distortion to the sound. Now sometimes this is what you want, it actually sounds good, but sometimes it can make things sound kind of ugly and aggressive. So you just want to listen out for distortion when you’re using sidechain compression. And if you find that you’re hearing distortion on the track, just slow down that release time and that’ll usually solve the problem.

The second thing you want to watch out for is distracting dynamics. Now whenever you’re using sidechain compression to create clarity and separation between two different tracks in your mix, what you’re really doing is punching holes in the track that you’re compressing. So whenever that sidechain compressor kicks in, it’s going to temporarily dip the volume of the track that it’s compressing. Now in many cases, this can be transparent, you don’t really hear it. But in other cases it can sound kind of unmusical, and it can draw our ear away from whatever the focal point of the track is. So maybe that’s the vocal or the guitar solo. If we’re hearing a bunch of dips in volume on a certain track, our ear is naturally going to be pulled towards that sound, and that can really distract us from what we should be focusing on in your mix.

So you want to be very careful when you’re applying sidechain compression and listen out for this type of effect. And if it’s creating something that sounds unmusical and unnatural to you, you may want to go with a different technique to create clarity and separation, or you may want to just adjust the settings on your sidechain compression to be a little bit more subtle – so maybe turning down the ratio or turning up the threshold so there’s not as much compression being applied. Or you can slow down the release time so the compressor kind of comes back to normal volume a little bit more slowly, and that can be a little bit less distracting. So just listen out for these types of dynamic problems when you’re using sidechain compression, and make sure that you’re not creating more problems than you’re solving when you’re trying to create more clarity and separation using this technique.

Now if you’re ready to dive deeper, make sure you download my free sidechain compression cheatsheet, which includes some additional tips and tricks that I didn’t cover in this video. Click the link above or in the description below to download this free cheatsheet right now.

And before you go, leave a comment below this video and let me know – what’s your go-to plug-in for sidechain compression? I’d love to hear from you, so leave your response in the comments section below.

Thanks so much for watching, and you can check out more mixing tips like these right here on my YouTube channel or at BehindTheSpeakers.com.