Do Synths Need Compression?


Are you wondering whether you are getting the most out of your synths?

Compression is a concept that can be hard to wrap your head around as a musician or producer. So it is worth spending some time getting to grips with whether or not it can help with your mixing. In this guide we’re exploring compression and whether or not it can make your synths sound better.

Synths do not necessarily need compression. They certainly don’t need it in the same way that vocals and some acoustic instruments often do. In these cases, compression is used to regulate the volume, keeping the peaks in check so there aren’t too many loud and quiet spikes in the music. This is also known as minimising the ‘dynamic range’ of a track. This is something of a “utility” rather than an “effect”.

Compression helps to neaten up the music you have recorded. Vocalists and guitarists naturally have quieter moments and louder moments, but a synth will usually not have these same extremes due to the fact that the sound levels are not particularly touch-sensitive and are produced electronically rather than acoustically.

This is not to say that compression cannot be used on synthesizers, and its use isn’t uncommon. However, rather than regulating the volume from the sense of compensating for playing, it is often playing around with the ADSR and impacting upon the characteristics of the sound, such as the attack. Instead of a utility for synths, compression, when it is use, is used as a full on effect to create interesting unique sounds in a track.

What is a Compressor?

Compressors can either be post-production tools in your digital audio workstation, or they can be physical pieces of hardware in a studio or in a guitar rig. 

To understand why it might be used on a recording of a synthesizer, it is important to understand what a compressor does to the sound. You don’t even have to fully understand how it works, just how it is likely to make affect your audio. 

I remember before I learned what a compressor did I was very daunted, it sounded complicated and a tool saved for use only by experienced producers. But it turns out what a compressor does is really quite straight forward.

A compressor will impact the ‘dynamic range’ of audio, this means how loud and quiet the different sections get. It puts all of the audio on a more even keel, either by attenuating the audio when it creeps over a certain volume, or by boosting the volume when it dips too low. It “compresses” the audio range so that the sound is far more consistent.

In the screenshots below of two sound waves you will see the first uncompressed signal which has a large dynamic range (difference between quietest and loudest notes). Below that is an image of a soundwave that has been compressed and you can see the difference between quietest and loudest notes is much less.

In modern music production, compression is very popular, and it is used on the final mix as well as individual parts of the mix such as vocals and guitars.

If you want more details on how compression works in music check out this article I wrote on the subject.

Dynamics on a Synth

Some synths are touch-sensitive, some are not. This means that in some cases you will be able to play sounds more quietly and introduce dynamics yourself. This mimics what an acoustic piano would do when you press a key more softly or with more aggression.

This is not always the case though and many synths output sounds at a consistent volume no matter how hard a key is pressed. 

If you have a sequence on a synthesizer that you have recorded and you are looking to “even up” or compress the sounds then you can look to do this in the same way you would an acoustic guitar. It makes it sound like the synth has been played more consistently. However, many synths won’t need this to compensate for uneven playing.

Dynamics and variation in synth sound waves instead often come from the ADSR envelope. The attack, decay, sustain and release. Though these can be edited through the synth itself, you can also make changes by using effects, compression being one of them.

How to Use Compression Creatively on a Synth

This is what a lot of people love about music production – the chance to experiment. A compressor on a synth won’t drastically alter the sound but it will make some changes to the audio properties.

Some of the uses of compression for synths include:

  • Sidechain compression. This means using an audio input to control the compressor, so that the sound “ducks” as another sound comes in. The prime example of a sidechained sound would be “Call On Me” by Eric Prydz. This sound might be viewed as a bit dated by some, but sidechaining can be used more subtly. The “sucking” sound you hear with each kick drum is the result of sidechain compression.
  • You can compress a synth sound with a slow attack compressor, to give a sharper attack or “pluck” sound on a synthesizer.
  • You can use a compressor to bring out some of the quieter elements of the synth, or make it more even-sounding. For instance, you might not want your bass to have much in the way of dynamics, as you want it punchy and prominent all through it’s ADSR envelope.

It is a case of experimenting with the parameters. For instance, the ratio, which basically refers to how drastically the impacted dynamics are being compressed. There is a lot that you can do when it comes to compression and if you are the sort of person who likes to spend hours tweaking your mix then you can certainly do so.

Should I Compress a Synth Live?

In a live environment, there is certainly nothing stopping you from compressing your synth sound, but it might be overkill.

A lot of the time, unless you are going drastic with an effect like the sidechaining effect, then you might not need to compress in a live environment.

Running a synth through a compression pedal probably won’t have a huge effect, and it will not be worth doing. This is more of an effect for tweaking a sound rather than creating something new and unique, therefore, the live use is not as prominent as studio use.

Best Compressors for Synths

There are so many different suitable compressors for use, so what is the best compressor for synths? We would say that a post-production effect is likely to be more of a beneficial addition than a pedal used for tracking. 

Once you have recorded a synth line, you can use the compressor to tweak and impact upon the sound qualities.

Personally I think the built in compressors in most DAWs do a great job if you are looking to manually dial in the settings. There are plugins out there that will do the work for you but I always think it is best to learn how to do it yourself if you can.

Summary – Do Synths Need Compression?

So, what is the final word on this subject? We would say that in the majority of scenarios, synths do not need compression, but that doesn’t mean that it can’t be useful or that it won’t sound good. 

With some instruments, compression can be used as a utility, to compensate for errors or to make a more reliable recording, but in the world of synthesizers, compressors are used in a more creative way, with sidechaining or similar effects being used by many producers.

In a live environment, in most scenarios, we would say don’t worry about compression, but for those who want to utterly perfect their sound overall in the studio, compression could be the missing effect that makes your sound take on that extra quality you have been looking for.

Rob Wreglesworth

Rob has come to terms with the fact he will probably never be a famous rock star....but that hasn't stopped him from writing and recording music in his home studio. Rob has over 15 years experience of recording music at home.

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