Dynamic sound processing. Side-chain. Part 1.

Today we will talk about such a useful and very popular technology today as side-chain compression. Surely, almost every one of us has heard this fashionable word, and many people clearly imagine what it is. But what capabilities are actually hidden behind this tricky form of dynamic processing? How exactly does side-chain compression work, and what tools can we use to achieve it? How to effectively use side-chain in practical dance music writing?

We will try to answer all these questions.

What is sidechain compression?

So how can you use sidechain compression in your tracks?

Well, let's start with compression in its most basic form.

Compression is a tool for managing dynamic sources. Before conventional compression, engineers had to control volume peaks and drops using faders. When the compressor was invented, engineers had a unique way to automate this control.

Sidechain compression is very similar in that you deal with all the same parameters as a compressor, including threshold, attack, release and ratio.

However, the "side chain " is what sets this technique apart from a standard smart compressor volume control.

When using a regular compressor plugin, you can control the channel your plugin is inserted into. When you connect the sidechain input of a compressor, it begins to control another audio source .

For example, you can put a compressor on a bass guitar track and set a sidechain on the kick drum, meaning the kick drum is the track that will drive the compressor.

In this situation, when the kick drum hits and gets loud, the compressor clamps down on the bass guitar.

Now you might be asking yourself,

Does the compressor in my DAW have a "sidechain input" or do I need a special plugin?

Work for the future

Sidechain technology makes it possible to implement interesting things in the Bitcoin space.
For example, you can implement a sidechain that is mined only by employees of one company. This sidechain will be some kind of implementation of the company’s wallet with open transactions. Also, the sidechain can be mined by hundreds of companies that are members of the federation - such a blockchain will be less susceptible to censorship. At the same time, the technology retains such advantages as decentralized security and transaction transparency.

Additional reading on the topic:

• “Your next step to blockchain”: release of the Exonum platform from Bitfury Group
• “Ultimate” blockchain digest: materials on Habré and other sources on the topic
• 1st transaction on the Lightning Network using the Bitcoin protocol

What is a sidechain compression plugin?

If you're using sidechain compression in Ableton, Logic, or Pro Tools, standard compressors come with a sidechain input. However, many producers use special instruments with sidechain factory presets to get the best sound. Most of these plugins are focused exclusively on sidechaining.

Some of our favorites include:

• Kickstart by Nicky Romero
• Shaperbox 2 by Cableguys
• LFO Tool by Xfer Records
• Trackspacer 2 from Wavesfactory

Cosmetic and dynamic applications of Side Chain

Personally, I divide the use of side chain technology into two variations: cosmetic and dynamic. I call cosmetics all cases in which the effect of the device is clearly noticeable and it rigidly cuts out specific areas of the instrument being processed. These are the examples that we considered.

What then is meant by dynamics? Here I include all the more subtle cases in which high compression ratios and low thresholds are not used, and the essence of such compression is to impart subtle dynamics. And the result in this case will be heard only if you listen to the mix first with the device turned on, and then without it.

The essence of this compression is to finely balance the elements in the mix, but this will only be possible with good monitoring. Otherwise, you may simply not catch the balance, over-press, or, on the contrary, under-press, and incorrectly adjust the attack and release times of the compressor.

This is a delicate work, specific to each specific case, and if done correctly, you can achieve miracles in dynamics, the main thing is reasonable use and the presence of good acoustics.

Sidechain Compression History

The history of sidechain compression began long before electronic music became popular.

In fact, one of the earliest developments of this idea involved over-compressing a signal.

Let's take a drum kit for example. If you put a compressor on a drum bus and squeeze the life out of it, you'll probably notice that the drum kit dominates the compressed sound, almost drowning out softer sounds (like cymbals and hi-hat) with every hit.

One significant early example of this can be found in the song Tomorrow Never Knows by The Beatles:

You will notice that with each kick and snare, the cymbals go out and turn into a white noise-like blur.

Eventually, in the late 90s, dance music took over.

Of course, the main emphasis in dance music, as it has always been, is on the drums. The most important drum in the mix is ​​the kick drum.

No matter what was happening on the kick drum in a dance track, that beat had to be heard loud and clear to get the crowd moving. It was during this time that we saw electronic music artists begin connecting their melodic tracks to the kick drum in very overt ways to make it hit.

An early example of this can be heard in Daft Punk's hit "One More Time":

Around this time, hip-hop pioneers in the 90s began to take on sidechain compression to see who could create the most powerful drums.

On a quick listen to J Dilla's "Dime Piece" album, you can hear that the entire track has a kick drum sidechain.

Benefits of Sidechain Compression

One of the obvious benefits of side chain compression is clarity .

Producers and engineers use this technique to get other, less important tools out of the way for the ones they want to focus on. Whether the main instrument will be a kick drum, a bass track or a vocal is entirely up to the producer or engineer.

Sometimes when mixing we want the best of both worlds. For example, we might want a kick drum to hit hard, have a low end and a rich midrange. However, we also want the bass line to have deep sub and rich lows.

It's often difficult to get both of these things using just an equalizer, since they share the same frequency range. However, by installing a sidechain compressor on the bass track and routing the sidechain compressor's input to the kick track so that the bassline disappears for a split second on each hit, you can get the best of both worlds.

A Step-by-Step Guide to Sidechaining Your Compressor

The first thing you need to do is purchase a compressor plugin that is capable of side-mounting . Most DAWs come with built-in sidechain compressors, so you're in luck.

Once you receive your compressor, follow these steps:

#1 Add your compressor to the track you want to bend

The compressor will move to the track with the audio signal you want to attenuate. This is usually a less important track that you want to move out of the way of the important track. To show you how to do this, I'll be using the standard compressor in Pro Tools.

I'll start by installing a compressor in the insert slot on the bass channel.

#2 Sidechain to a track that needs more clarity

In the top right corner of this plugin you will find a “sidechain” button. It will look different in each plugin, although the method is the same. Once you've enabled the sidechain, route it to the send in the top left corner. For this example I chose 27-28 tires .

Then I'll go to the drum track and create a send to bus 27-28 so the sidechain compressor can pick it up.

#3 Adjust settings

At this point, every time the kick drum plays, the bass signal should drop. You will need to adjust the settings to suit your track. We recommend starting with a 2:1 ratio and lowering the compressor threshold until you hear the gain reduction you want.

For a more subtle approach, we recommend reducing the gain by 2-3 dB . However, if you want very obvious EDM-style sidechain compression, you can increase the threshold.

Then adjust the attack time . Typically, the attack time should be fairly fast (around 2ms or less). Remember, you want your less important signal (the bass guitar) to immediately move out of the way on every hit.

As for the release time , it depends more on taste.

We recommend starting with a fast release time, less than 50ms, if you want to maintain a subtle sound. However, for dance music, where rhythm is important and sidechain compression is more noticeable, you can time the release to coincide with the track.

How it works

Before moving directly to specific instruments, let’s look at the general principle of how side-chain compressors work in sequencer programs. The key signal is sent via a send to a certain bus. Next, in the plugin itself, you need to specify from which bus it should receive the key signal. When such a connection is established, the compressor will analyze the incoming key signal and, if this signal exceeds a specified threshold, process the main signal.

This is the general principle; only its implementation in different tools is slightly different. And if a few years ago sequencers did not provide built-in tools, and it was possible to consider specific plug-ins directly, now all modern programs have very good built-in tools and the use of third-party plug-ins in such cases often becomes impractical.

Having examined all these instruments, we will also compare their sound and processing quality using specially prepared examples with equal settings.

Cubase
4/5
Let's start with Cubase. Since version 4, such variations as Cubase 4 and Cubase 4 Studio have a side chain function for a wide range of plug-ins. To create a bundle, first of all you need to add the plugin itself, in our case it will be the standard VST3 plugin Compressor and activate the side chain function on it. To do this, just click the appropriate button:

After this, from the key signal, the Side-Chain section will appear in the send list, which will display all the plugins in the project in which Side-Chain input was activated. All that remains is to select the appropriate target and set the send level. Otherwise, this is a very ordinary Send, for which you can adjust the level and send it in pre-fader mode, which we will need very soon.

More information about how the send scheme is implemented in Cubase and what Send is in general was described in detail in the second part of our material on Cubase SX 3: “Cubase SX: continuing our acquaintance.”

Let's take a look at the plugin itself. All settings are basically standard. Please note that automatic Makeup Gain compensation is enabled by default and the plugin will automatically compensate for the output signal level. Personally, I immediately turn off this auto-compensation and set Makeup manually. There is also an Analisis knob with which you can switch between peak and rms modes: in the left position the compressor will work in Peak mode, in the right position in RMS mode, respectively, and we can select a certain average balance.

Ableton
Live 8
In Live 8, the side chain function is implemented even more simply. We add a processing device, in our case it is a regular Compressor, and activate the side chain using the button of the same name:

Next, in the Audio From field, we need to indicate from which track, send or instrument we want to receive the key signal. In the next field we can select the switching mode: before insert processing (Pre FX), after (Post FX) or after the mixer (Post Mixer). Using the Gain knob we set the overall level of the incoming key signal.

Logic

In Logic, the organization scheme is almost identical to that used in Ableton. In the compressor window we have the opportunity to select the source of the key signal, and this can be any audio track, instrument or send bus. The easiest way is to send the key signal to some free bus (for example Bus 2), and close all Aux-s on the bus itself in order to avoid the key signal getting into the master again.

Next, on the plugin itself, all that remains is to select the source of the key signal, that is, the specified bus.

However, as it turned out a little later, we can just as easily select the desired track as the key source and then close the fader on it. The signal will still pass from the track to the compressor - the pre-fader.

TC Native Bundle

Having examined the tools of the three most popular modern sequencers, let’s finally move on to third-party, universal, so to speak, development - a bundle of Compressor/De-Esser + Side-Chainer plugins from the TC Native Bundle. This package, as we mentioned just above, is available in versions for both Windows and Mac OS and for all plugin formats: VST, AU, RTAS.

The key signal is transmitted to the compressor using a special plug-in with the appropriate name – Side-Chainer. This plugin is simply added to the Insert of the track that needs to be transferred:

The interface consists of only two elements - the THRU button, after pressing which the signal will no longer be passed on, and an indicator of the channel on which the side-chain will operate. Here we need to make a small clarification: in TC you can use no more than two channels. The first plugin added will transmit the signal on the 1st channel, the next one on the 2nd. Next, let's move on to the Compressor DeEsser plugin.

Here we activate the side chain mode using the Key Input button and then use the four sliders to set the basic compression settings. To the right of the Key Input button we can select from which channel we will receive the incoming key signal.

In the Display window we have an indication of the processing depth (Reduction) - the Red indicator and the level of the incoming key signal - Key. The left area contains sliders for adjusting the level of the compressor's input and output signals.

The main limitation of this package is the ability to use only two SideChainer - Compressor bundles.

Common use cases for sidechain compression

Create space for your strike

As we've already discussed, drums and bass have the same frequency range, so it's difficult for engineers to get the drum signal to penetrate without drowning out the low frequencies.

If you want the best of both worlds, we recommend using sidechain compression in combination with EQ to balance the kick and bass without compromising their timbre. In most cases, you can place a sidechain compressor on a bass track and route the sidechain or key input so that the bass drops out on every kick.

Creating Vocal Clarity

One technique I often use is side-chaining the vocals I'm mixing with other instruments in my mix. While you can use regular vocal compression to bring the vocal to the forefront, it doesn't always work as well as you hope.

For example, if I find that guitars, synths, or backing vocals are overpowering the lead, but I don't want to ruin their tone with EQ, I'll often connect them to the lead vocal track.

For this technique to work, you must use a fast attack and a fast release (less than 30ms). Every time a vocal is played, the instruments connected to it via the side chain should disappear immediately and quickly reappear after they disappear. Achieve a gain reduction of approximately 1-3 dB .

Many engineers even go so far as to include vocals across all tracks so that they remain in the foreground throughout the song.

Pumping

Pumping is one of the iconic techniques in EDM music. While this technique is used by almost everyone and their mother these days, we can thank dance music pioneers like Daft Punk and Eric Prydz for making it popular.

Chances are you've already heard this technique in action.

Typically, an EDM producer will connect instruments to a kick drum to dampen the sound whenever the kick drum hits. Unlike the other two common uses, which are subtle mixing tricks, this effect is more or less creative.

Use extreme compressor settings and synchronize the release time with the tempo of the track.

ABOUT TIP: To determine the exit time, you can use the equation:

60,000/BPM = quarter note per second (ms) .

For example, let's say you're working with a 120BPM track. You can plug this BPM into the equation to determine that a quarter note lasts 500 ms .

(60,000/120 = 500 ms)

If you want your release to be as fast as an eighth note, you can divide this number by two.

(500/2 = 250 ms)

However, if you're working with a track that feels like it's time-out, you might want to double this number.

(500 x 2 = 1,000 ms)

"Hidden" key

The simplest option for organizing side-chain compression on a kick drum in the form of a key is to create a send to the side chain directly from the main track of the kick drum. However, with this type of organization, you may encounter one small (or even big) problem - at least the side chain will not work in pits and other places where there is no barrel, but the effect is needed.

Therefore, it is much more convenient to use a method that I personally call a hidden key.

The essence of the method is very simple - you export a small loop with a kick drum (or another instrument that you want to use as a key) to a file, then insert this loop onto a separate track in the project and multiply it over the entire sound of the composition.

Next, you need to create a pre-fader send (Send) at 0 dB from this track to our effect (or some bus, depending on the sequencer you are using) and lower the track fader completely. In Cubase 4 it looks something like this:

The essence of the trick is extremely simple - through a send, the track is sent to the side chain of the compressor and is present in all places in the composition, while the main kick drum track will perform its usual role. And by adjusting the send level using automation, we can create the effect of “unwinding and straightening” elements.

Unusual Use of Sidechain Compression

Ducking Reverb and Delay

In pop music, it's especially important to keep the vocals front and center. However, if you want to layer reverb and delay on vocals, keeping them at the forefront of the mix becomes problematic.

One unique way producers can install massive reverb settings on pop vocals without drowning them out is by connecting reverb and delay to the lead vocal.

Simply create a bus for time-based vocal effects and place a sidechain compressor on it. Then route it to the lead vocal so the effects kick in every time the vocalist sings a line.

Reducing the amount of crackling in overhead microphones

If you record live drum kits, you've probably encountered the problem of too much crackle in the top plates. To solve this common problem, you can install a compressor on the overheads and route the crackle as a trigger signal, so that every time the crackle is played, it bleeds into the overheads.

Lo-Fi Hip-Hop Vinyl Noise

Most amateur hip-hop producers overlay their tracks with a looped sample of vinyl noise and that's the end of it. However, experienced producers take it one step further by layering this vinyl noise to make it part of the track .

One of my favorite things about making lo-fi hip-hop is finding a good vinyl noise sample and looping it on the track. Then I put a compressor on it and use the drums and crackles as triggers. Every time the drum and crash play, the vinyl noise will slowly fade away.

By doing this, you add rhythm to your track while sticking noise to the drums to make it sound more realistic.

Examples of sidechain compression in music

"One More Time" - Daft Punk

We have to give it credit. We know you've probably heard this song a million times, but it's one of the best and earliest examples of proper sidechain compression in dance music.

At 0:45 a drum kit comes into the mix. If you listen closely, you can hear the bass fade out every time the kick plays, giving the track a unique pumping effect and ensuring the kick is clear.

"Hey Mister Tree" - Amon Tobin

For a weird and wild example of sidechaining, check out Amon Tobin's song "Mr. Tree".

Amon uses this technique on almost all of his tracks, allowing the kick to cut through every part of the mix, creating glitchy and sibilant effects for unique rhythms and hard-hitting drums.

"Never Catch Me" - Flying Lotus

Sidechaining has been an important part of hip-hop production since the days of J Dilla, although you can still hear it in modern hip-hop tracks. A great example of this can be found in Flying Lotus' "Never Catch Me" at about 3:45.

The kick drum shoots through the mix like a series of gunshots.

Tips and tricks for sidechain compression

Ignore bass frequencies

Advanced mixing engineers often use side-chain compressors that ignore low frequencies to achieve clean compression without pumping artifacts.

Most stock equalizers come with sidechain frequency .

You can enable these controls to prevent certain frequencies from being monitored at the sidechain input.

A great example of this is mix bus compression .

Low frequencies are much more powerful than high frequencies. So if you place a compressor on the mix bus, the low frequency peaks will hit before anything else, often resulting in unwanted pumping.

While modern compression in mastering can keep high-frequency instruments like guitar, vocals or synths under control, it will clamp down the mix with every 808 hit or low bass note.

You can avoid this by using a compressor with a built-in frequency sidechain. We recommend setting the high pass filter on your compressor to 100Hz to start with and adjusting to taste.

Isolating frequencies

You can apply a sidechain effect to specific frequencies if you have a multiband compressor in your plugin toolbox. In this case, the side chain is triggered only when a certain frequency range gets out of control.

For example, let's say you have a guitar solo in a hard rock track and you want the high mids to cut through the wall of the rhythm guitar, but you don't want to EQ the high mids out of the rhythm guitar and lose the sound.

Instead, you can install a multiband compressor on the rhythm guitar bus and route your lead guitar's audio signal to the high-mid sidechain. Again, as with the vocals above, you should use a fast attack and a fast release.

Every time your lead guitar plays a note, the high mids are taken away from the rhythm guitar.

The practice of using side-chain compression

So, we have examined all the main theoretical points and the implementation of side-chain compression in different programs and plugins. Now we can talk directly about the practical use of technology in writing dance music and some of the techniques used in this.

Side-chain compression: a typical case

In the simplest case, a kick drum is used as a key for a side chain, and the processed instrument can be any drawn-out sound, be it a hissing FX, a pad, or even a bass. Let's look at one very simple technique that was often used by different people when writing electro house. I prepared a small drum loop used in the example at the beginning of the material and synthesized a regular sawtooth bass. The bass was played with long notes and the result was something like this:

It hardly makes sense to launch him with a rhythm section in this form. However, after processing it with a side-chain compressor and a key-shaped kick, it takes on a slightly different shape:

Now let’s listen to the resulting bass line along with the rhythm section and the hissing FX we used in the previous example:

Now we can clearly observe how two seemingly inconspicuous instruments acquired sound dynamics and fit into the mix. At the same time, the barrel with snare sounds clean and well readable.

I note that the noise FX sound was used as the first one available, and the sawtooth bass was turned out from the default preset of the Rob Papen Predator VST instrument. The following compression settings were used:

The lower we set the threshold, the deeper the processed element will be pushed. At the lowest values ​​we can generally achieve a full gating effect.

A kind of electro sound in 5 minutes

Gate in
Sidechain
Let's look at another no less simple and effective method of using sidechains, only this time we will, on the contrary, emphasize certain areas using a gate.

Let's say we have a drum loop from which we need to remove everything except the hi-hat. You can, of course, process the loop manually, cut it, add fades, but it is much simpler and more efficient by all criteria to use a gate in side-chain mode. As a key, we can transmit any line of hats that are located in the desired way and have a suitable sample length.

By and large, we use the key signal as a mask, which the plugin will use to separate only the areas we need.

We have a loop like this:

I used this hat line as a key:

Next, a gate with a minimum threshold and fast attack-release, operating in the Side Chain mode, was added to the processed loop:

As a result, we extracted only the elements we needed from the loop:

Approximately the same result can be achieved by using an expander in side-chain mode instead of a gate, but the gate gives a tighter cut, which was preferable in this case.

FAQ

Why is it called sidechain compression?

In the 1930s, Douglas Shearer coined the term when he created a compressor that used a "side" signal circuit that was different in parameters from the compressor's main trigger. This side signal used an equalizer and could only be triggered when a certain frequency appeared.

What is the point of sidechain?

One of the main points of sidechaining is creating clarity in the mix. You can use a sidechain compressor to help an instrument cut through the mix without compromising the tonal characteristics of other instruments that are masking it.

Is sidechain compression necessary?

While sidechaining is by no means mandatory, it is one of the most useful techniques in modern music production for creating clarity, whether you use it on vocals, drums, bass, synth, keys, or guitar. In EDM, this technique has become the main one.

How do you strengthen your voice?

To connect vocals to the sidechain, determine which instrument you want to connect it to. For example, if it's a drum kit, you can set a compressor on the drum kit channel and send the vocal to the input so that every time the kit hits the vocals will decay.

Is it necessary to use sidechain for kick and 808?

If you use a kick with a sharp transient, there is no reason for your 808 to have a transient that competes with it. To get rid of the harsh transient, you can either use a transient driver , or connect the 808 to the kick so that the transient decays with each kick drum hit.

Is it possible to do reverb using a sidechain?

Sidechaining reverb is a common music production technique that allows you to get the reverb out of the way when playing a dry signal. For example, you can connect a reverb to a vocal so that the reverb sound disappears when the vocalist sings a line. This technique helps create clarity.

What genres of music use sidechaining?

Although sidechaining has become popular in EDM and hip-hop, it is slowly making its way into almost every genre. While its use may be more subtle in modern rock or pop recordings, it certainly has its place in various genres of the music industry.

Why side

Imagine that you can send cryptocurrency not only to the addresses/wallets of other people and centralized services, but also to other blockchains.
This is the sidechain. Sidechaining is a mechanism that makes it possible to safely use tokens from one blockchain in another, while maintaining the possibility of reverse transfer. In this case, the original blockchain is called the main blockchain, and additional blockchains are called sidechains. For example, a private Bitcoin network capable of transferring currency to and from a public blockchain would be considered a sidechain for that network. Stack Exchange residents offered an analogy to describe how sidechains work. The Federal Reserve prints US dollars on behalf of the government - this is the main blockchain. However, tourists can take money and take it to other countries - sidechains - with a different economic situation. However, this currency will still be backed by the US government.