Synthesis in Sound Design
with Concept

Concept is the Krotos soft-synth that offers a simple and intuitive workflow for creating massive basses, moving pads and screaming leads, but today we are going to explore other ways of using this software – we’re going to use it to create sound effects. 

Throughout this blog post, I am going to demonstrate a couple of examples of sounds that you can create using Concept such as user interface elements, Sci-Fi weapons or cinematic effects. All of the created patches will be available for you to experiment!


The cinematic sound design staple: the ‘BOOJ’

Modulated bass drop, also known as a BOOJ is a staple of cinematic sound design. In essence, it’s a low note continuously falling in pitch with a tremolo effect applied. For this one, we are going to use the Envelope mod. Set your ADSR to long Decay and no Sustain and set a long Attack in the Envelope mod. It should look like this: 

Now, let’s start modulating parameters. We’re going to need a falling pitch effect, so let’s add Detune to our mod.

P.s. in my example, I am using two oscillators, one being a blend of sawtooth and triangle waves and the other one combining a sine wave and white noise but you can use whatever you like. 

You should hear the pitch fall now, but we’re not done yet! 

Let’s add a Ring Modulator to the FX chain and modulate the FREQ. In the sound we want, the frequency of the tremolo will be falling down.

Now let’s add some finishing touches to make the sound more interesting. I added a Flanger, Saturation and modulated the Cutoff of the main filter so that the frequency is “chasing” the falling note. The whole patch looks like this:

And here’s our final sound:

Nice thing about those kinds of sounds is that by small tweaks you can get a really large variety of them. I made a second patch that differs only in addition to falling FM synthesis, and the sound has already changed significantly and sounds like something out of some kind of a Sci-Fi droid movie.


Creating whooshes is one of the most common sound design tasks. Let’s look at how you can use Concept to design organic windy whooshes. 

There are a few key elements to this. First, select the white noise generator as your sound source. We will also be using XY Capture to “draw” the whoosh parameters. 

We will want to assign different parameters to different axis of the XY Capture so we can move the puck in a kind of a triangular way to create a whoosh.

Assign the Pan to the X-axis and use the full modulation range so the whoosh will move from speaker to speaker.

Assign the Gain and filter Cutoff to the Y-axis so the whoosh gets louder and richer-sounding the higher you move the puck.

Now you can play a sustained note and either perform your whooshes in real-time or use the XY Capture feature and create a looping modulation shape. It’s up to you! 

I’ve also added some very light tremolo effect, a flanger and added some reverb. Making parameters of those effects react to the XY capture is a nice way of making the whooshes more interesting.

The end result sounds like this:


Synthesis is a great way of getting sounds for a futuristic user interface. To make our own, we are going to look at some creative ways of using Delay modulation in Concept. 

This preset is going to be based on a very short Envelope mod. Something around 145 milliseconds of Attack will do. 

We are going to use both of the oscillators and move them a couple of octaves away from each other. The choice of waveforms is entirely up to you but I do recommend using FM synthesis to add metallic overtones. We are also going to modulate the Detune in both. My oscillator bank looks like this:

We are also going to use the filter and make it very resonant. 

The decay of our ADSR is slightly longer than that of the Envelope mod.

If you play some notes in the high register, it will already sound like a UI beep. Let’s make it more interesting by adding some Delay modulation. 

Add the Delay effect and make sure that it is in Sync mode. This type of delay has only a couple of set time values and it has to jump between them when we modulate them, creating interesting glitchy effects. We are going to use this to make an underlayer of short glitches that will make our sound more SciFi.

You can determine how much of this layer you want by changing the Feedback and Mix values. With higher Feedback, the sound will change into a more of a startup sound.

The effect is subtle because we are using a very short Envelope mod. If we’d have increased it’s length and turned up the delay mix of the reverb, we’d get a glitchy droid sound!


We are going to revisit the approaches we used while making the Booj and use them in a different situation and also see what we can achieve by layering sounds made in Concept. 

We’ll be making sound for a Sci-Fi plasma cannon that charges up and emits a massive blast of energy. We’ll definitely need more than one sound for this so let’s take this step by step. 

1. Charge

We’ll make a sort of a reverse Booj by ramping up the pitch and the modulation of the sound to create a feeling of gathering energy for a discharge. Let’s create a long Envelope mod and add parameters from the oscillators bank so that they are ramping up. 

Now let’s add a Ring Modulator, the same as with the Booj but this time, let’s make the frequency of the tremolo go up.

This is the essence of the sound. Add any other modulation you think would make it more interesting and we’re done with the first part!

For my charge I also created an additional layer that uses different waveforms and FM synthesis ranges, modulated noise to create a “mech” layer and create a very simple sub layer by taking the modulation we described above and selecting a sine wave as the only source.

As long as you keep the Attack and the frequency of the tremolo the same, they will sync perfectly.

2. Blast

A really short, snappy blast layer that goes right before the discharge is a nice way of adding cadence to your sound. The preset 808-ish KICK in Concept works for this very well. You might want to add a Transient Shaper to give it more punch.

3. Discharge

To make the a discharge sound, I flipped the modulation that was present in the charge-up by setting a minimum Attack and increasing the Decay. This way the sounds are still quite similar and create a feeling of fitting the same style. I experimented with the Decay times to see what would make the discharge sound aggressive and snappy.

The full cadence sounds like this:

We’d probably be using some additional content from Weaponiser and Reformer by adding some real-world gunshots and gun handling Foley to add to the believability but the essence of the sound is here!


As you can see, we are using one modulator to achieve the desired effect and I do think that with those types of synthetic sounds it is much more important to choose the right parameters to modulate and make that one modulation interesting than use a lot of different modulators. If you’d like to increase the variability of those sounds, you could use any other modulator as a kind of a secondary mod, that would make slight changes to parameters to make them more varied.

Those were just a couple of many ways in which you can create sound effects inside Concept. If this has sparked your interest, then head on to the product website, where you can check it out with a free demo.

I hope this inspires you to make some noises!

Download presets Demo Concept

Download the free presets & a Concept Demo

To use the presets created in this article, drop the files to:

Mac: Users/(user)/Libray/Application Support/Krotos/Concept/Library/Presets/main

Windows: (root)/Users/(user)/AppData/Roaming/Krotos/Concept/

This will place the presets in your User Presets folder so you can experiment with them at your own leisure.

And don’t forget your free Concept demo to follow the tutorial with the presets.


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