Igniter is Krotos’ new engine sound design plugin. They have been kind enough to sent me a license to have a look and see what it can offer. Igniter allows you to virtualize vehicle engines (real, sci-fi or fantastic) combining a granular section, a set of synthetizers and two sample managers. It includes performance controls so you can automate the vehicle RPM, engine load and many FX (including doppler) in order to get a realistic sounding engine. It comes with a big amount of presets including sport and utilitarian cars, planes, helicopters, trucks, motorbikes and sci-fi vehicles.

So here is my in-depth look at the plugin features with some examples here and there. I encourage you to follow along in your own DAW, you can find a full featured demo here.

Interface / UI

The interface is clean and easy to read and you can resize the window which is very nice. A main section (left side) occupies most of the screen and includes all the audio sources we can use. These sources are divided into four different tabs: Granular, Synth, One Shot and Loop and also includes a file browser.

On the right hand side we find the engine master on/off switch and the main revs knob in the middle. This revs knob acts as a gas pedal for the whole plugin. At the top, we find the Mod system, where Igniter’s true power resides, since it allows you to dynamically link any parameter within the plugin to the revs knob using envelopes and LFOs. Lastly, at the bottom right side, we find the FX and mixer sections. Let’s see all these in more detail.

If you need more info, most features are well covered in the manual and on Kroto´s videos. What follows is my own take on the plugin capabilities, plus some wish list features that I would love to see in the future.

Granular Section

This is probably the most complex and important generator. It combines granular synthesis with real recordings to re-create a virtual engine with a revolutions or RPM knob that you can “drive”. Each vehicle includes two mic perspectives: engine and exhaust and we can easily mix between both with an slider.

When I saw this, it occurred to me that it would have been nice to also include an interior perspective as this would be very useful for vehicle scenes like chases. After some looking around, I discovered that all vehicles have a “In-car” preset which solves the problem. But this is not a true recording of the car interior, but a recreation of it using EQ and convolution reverb. Would this be too different or unauthentic compared to a true inside recording? To be honest, I don’t know since I don’t have a huge amount of experience doing car sound design but I suspect these presets will suffice pretty well for most applications and, of course, you can always tweak them to suit your needs or even do your own "in-car” processing outside of Igniter.

In terms of how the granular engine actually works, we can’t see what’s going on under the hood (see what I did there?) but I suppose the plugin is using recordings at different steady RPMs and blending them together as you act on the engine. This is similar to the approach used in middleware like Fmod for use in video games. The result is pretty natural and smooth and driving the RPM feels responsive and clean.

For now, you can’t add your own sounds to the granular section, as they would probably need to be edited in a very specific way for them to work here. On release day, Krotos offers 13 different vehicles that use this granular option but I’m sure more will be added with time or maybe made available for individual purchase in the future.

Driving Modes

As you can see on the interface above, there are basically two ways to control the engine simulation: manual and auto. At the same time, every car comes with a set of three presets, two of them are manual and a third uses auto. So, using the example pictured on the right hand side with the Dacia 1310:

-Dacia 1310: “Free” mode that uses manual driving.
-Dacia 1310 Manual Gears: Uses manual driving but with pre-determined gear shifts on the Revs progression.
-Dacia 1310 Auto Gearbox: Uses the auto mode.

Let’s see what’s the difference between these three:

In general, manual mode allows you to freely change the engine’s RPM an also gives you a “load” knob. This parameter simulates if you are putting pressure on the engine or, in other words, if you are applying pressure on the gas pedal or not and allows us to create more realistic sounding gear shifts and decelerations.

The difference between both manual presets is that on the “free” mode, the relationship between the granular RPM and the master rev knob is completely linear by default, so you have to play with the RPM value yourself to imitate the act of shifting gears. Here is a video of me just doing that with a Revs pass first, followed by a Load pass. As you can see, to achieve a natural result, you need to drive the parameters in a realistic way. It would require a bit of practice to follow onscreen action like this but it feels very easy and responsive.

On the other hand, the other preset type, “Manual Gears”, has the gear shifting already soft coded into the mod section, including on load and off load changes. Of course, you can tweak this as you please but the preset gives you a nice starting point. As you can see, in this mode you don’t need to imitate the engine revs with your automation and you can just use curves to describe how hard you want to accelerate or decelerate.

For the most part, this works quite well when going up on the revs but going down forces you to go through the whole set of gears which doesn’t always feel natural, although sometimes you may want this (Formula 1 cars kind of do this sometimes). I tried different ways to avoid this, like staying within the boundaries of the same gear or jumping fast from a higher to a lower point on the envelope, although this needs to be carefully drawn as automation. A potential solution to this issue would be that the RPM ramps don’t occur when we decelerate, only on our way up on the revs knob.

You can also notice how the load drops are already coded into the revs progression, which is pretty handy and also shows that I was too subtle with it on my free test.

The third preset, Auto Gearbox, uses the auto option which doesn’t allow you to directly control the granular RPM or load and simply gives you an slider called “Power” that we can use to accelerate or brake while the gears shifting is hard coded and can’t be tweaked. This would be similar to driving an automatic car.

Here is an example of me using this mode. Compared to the others, it feels a bit unresponsive at the start but once you get speed it works well, although the gear shifting doesn’t always feel “in the right place”. As long as you don’t need very precise and fast changes in RPM, this mode can be useful to get natural results quickly.

By the way, you may hear some clicks and pops on my examples above. I am not sure a 100% if this is coming from Igniter’s or was a internal audio recording problem but definitely the Audi R8 seems to be a bit more “clicky” on the exhaust than other cars I tried later.

Granular Advanced Controls

Lastly, the granular section also includes some other advanced controls:

-Shuffle Depth controls how thin or wide is the slice that the granular engine uses to select the samples. Higher values can help make the sound more natural and varied. Using the mods, you can, for example, make this value go up as the RPM goes up.

-RPM Smoothing: It slows down the response time to the changes in RPM. You can try increasing this if the engine feels too wild or decreasing it for a more fast response, which could be useful on auto mode.

-Idle Fade: Use this to adjust the fade between the engine on idle and low revs.

-Crossfade: It controls the blending between different grains or audio slices making it more abrupt or smooth.

-Lim Threshold & Kick: The documentation doesn’t cover these two but I suppose they are related to an internal limiter.

Synth Section

It includes 5 oscillators with two different waveforms each that you can blend together. You can also control the frequency and gain of each of the oscillators. There is frequency and amplitude modulation available for each oscillator plus a vibrato option.

And that’s pretty much it. Sounds basic but it is indeed powerful as you are able to link any of these parameters to the master rev knob creating dynamic designs that will grow in intensity and speed as the revs go up. You can also combine synth layers with real engines to create hybrid engines that combine real recordings and synths.

Here are some examples of sci-fi designs I did from scratch. Something that I missed is more options for the noise generator. it would be great to have more noise colours to create textures with or maybe a filter to shape it. The ability to apply separate FX to different oscillators would also be amazing.

One Shot section

This tab allows you to trigger certain individual sounds on specific moments on the rev progression curve. Maybe the most obvious use for this section is to trigger tire skids when we go up on the revs or screeching breaking sounds when we go down. In any case, this section is great to add sweeteners and flavour to the design.

There are four slots where you can drag and drop sounds. Unlike the granular engine, you can use your own sounds here and drag and drop them from finder. Each slot can be monitored independently and there are individual knobs to control volume and pitch. Both of these can also be controlled with an envelope instead of a knob, which offers interesting possibilities.

On top of the sample area there are four “timelines” each of them corresponding to one of the slots. Here is where you can choose when do you want the samples to be triggered but the horizontal axis doesn’t represent time but rev progression. In other words, you get to decide where in the acceleration curve you want some samples to be triggered.

Directionality is also accounted for. You can trigger samples as the revs go up or as the revs go down depending of where the triangle is looking. You can also have a sample that will be triggered both ways (diamond shape) and stop currently playing samples on the slot (square shape).

In general, the system is clever and nice to use but I feel that you’d really need some playlist and randomisation controls to make it really powerful. My idea would be to basically turn each of the slots into something like an fmod event. This way, you could add a playlist of sounds and control how to cycle through them or randomly jump between them.

This will give you a much richer system, where you can use sets of skids, terrain or engine pop sounds to choose from each time the event is triggered. For this to work well, you should be able to choose how deterministic the system is, in case you need predictability. Being able to tweak or re-shuffle the samples that were triggered after a pass would be also a good approach. I know Krotos is working on a run-time, middleware version of Igniter, so maybe something like this is already in mind.

Loop Section

Although the one shot section includes an option to loop its samples, this tab gives us much more power and control of sounds that need to be looped. It can be used in conjunction with the granular system or just by itself to create a completely new vehicle system.

This is pretty powerful. It allows you to have your own responsive car design, provided that you have recordings of steady RPMs to use. You can also use the loop section it to add texture or detail to the granular generator. You can add things like gravel, dirt, snow, clattering, squeaking or engine pops and link their intensity to the master revs knob.

You have four slots for loops and you can control their volume and pitch. The interesting and very handy thing is the section on the upper side. It allows you to customise how you want to blend your four loops together giving you the tools to smooth out both the crossfades and pitch changes between the transitions.

To obtain a good result, you need to make sure you have audio clips that loop cleanly. The Amp section helps when determining the boundaries between the clips but I miss more control on the actual volume of each of the sounds when I need to balance them out. I’ve noticed that actually some of the factory presets use the mod section to control this by using the general gain of the whole looping section but this strikes me as bit left field. Shouldn’t I be able to control the gain of each sample with the amp section? A gain parameter independent of the crossfades is needed here, I think.

On the other hand, the Pitch section is very nice to have and it works well. It would be amazing to actually being able to analyse the pitch of each of the samples and get a “suggested pitch curve”. This could be just an starting point so you can then tweak them by ear later.

The workflow in the loop section is a bit odd since you can’t hear anything unless the main engine switch is on but then if you switch it on, the first loop triggers so you can’t hear what you want to hear in isolation unless you manually mute the first slot. It feels kind of odd. Additionally, when building the loop progression, sometimes a slot doesn’t emit sound and you need to manually hit its play button. Kind of annoying.

So here is an example where I’ve built a Peugeot 307 engine from library recordings. For sure, the result is not as smooth as the granular presets and it sounds a bit “processed”, it’s like you can hear the artificial pitch bending too much. There are also many dropouts in the audio level and I don’t know if this is my fault or if there is a way to remedy that. The factory presets that use the loop system are cleaner than this but I can still hear some dropouts on those so maybe this is a bug?

As for the sound in general, it depends on how you drive the RPM and I assume creating a robust and good sounding vehicle system takes more sample preparation and tinkering than my quick test took. I was also thinking that maybe I chose the incorrect range of RPM loops and I missed having more slots so I can use more RPM states and make the progression smoother.

Browser

It is used to choose and monitor samples for the granular, one shot and looping sections. The tagging system is very nice. Igniter includes a nice selection of different engines and sweeteners, many cars also include recordings of doors, horns or wipers ready to use. I’ve noticed that you can’t drag and drop these sounds from Igniter to Pro Tools, which will probably be my first instinct if I just want a car door sound on the DAW’s timeline. The alternative would be to have the sound on the One shot section and either trigger it via Pro Tools automation or via the timeline system.

Other than the factory sounds, you can also use the “Files” tab to browse around your own computer files, including external drives, which is very nice.

Something I’ve noticed and is a bit counter-intuitive, is that in order to preview a sound on the browser, the engine button needs to be on, maybe that’s the case because that button just mutes the whole plugin internally but it took me a minute to figure it out.

Mods

As I have mentioned before, this is a very powerful and important section of Igniter and probably the one that I liked the most. It reminds me of Propellerhead’s Reason where you can flip the rack and apply envelopes and LFOs to any parameter in the system.

Basically the mod section allows you to link any parameter within Igniter to the master revs knob. You just need to drag the name of the desired parameter and drop it on the mod area. Then, you can edit the envelope that will govern this behaviour and also use an LFO to add some randomness or movement to any of these relations. The range or scale of the change can be adjusted with the sliders that appear to the right of each parameter. There are 8 mod slots so you can create very different envelopes and very complex systems.

By default, the RPM within the Granular section is inked linearly to the master revs and from there, you can link all sorts of other stuff, including FX, to make the engine more dynamic and responsive. Have a look at the presets to get some ideas of what you can do with this, it really allows you to get creative.

I was also thinking that it would be very nice to be able to use the mod section on other things than the RPM. As an experiment, I tried to turn the master revs knob into a distance knob, decoupling it from the granular RPM and linking it in several ways to volume, reverb and EQ.

Why would I want to do this? Because controlling the distance and perspective between shots is probably one of the most time consuming things to do in a vehicle scene. My experiment kind of works although when you do this, you loose the ability to link other stuff to the vehicle RPM. So, for a really powerful, all in one, vehicle design tool, I would love to have 3 master parameters: Revs, Distance and a maybe a third custom one. This is maybe outside of the scope or workflow that Krotos had in mind but that is at least how I would try to design it. Of course, you can create a similar effect just on your DAW but using this method you are able to link many things at once to the “distance knob” like engine/exhaust mix, granular FX, reverb sends, etc, speeding up workflow massively.

FX & Mixer

This section is pretty straight forward, nice to use and clean. You can control the level for each of your audio generators plus you have an FX send and Pan pot. While the sends and FX are pre-fader, the Pan is post fader. Each section has a rack with 5 slots where you can hook up FX. The FX that we can use are:

-EQ: Very nice parametric EQ with everything you need. Works great.
-Compressor: Very good too, with a gain reduction meter and a limiter mode.
-Limiter: Simple and clean dedicated limiter, useful to make sure you don’t saturate the output at high RPMs.
-Saturation: Good for adding some extra nastiness to an engine with extensive controls and colour presets.
-Transient Shaper: An unusual addition to a plugin like this since engine sounds don’t have many transients but it could be cool to use to add or remove dynamics to the granular section or on sweeteners.
-Flanger: Nice for sci-fi designs.
-Noise Gate: I suppose it could be useful if you have a noisy recording on your one-shot section.
-Ring Mod: Pretty cool and alien sounding and a nice addition for creating sci-fi stuff.
-Convolution reverb: Very good to have to recreate distance or an “in-car” sound. The controls are quite simple but you probably don’t need much more. I miss more outdoors IR in the factory library.
-Doppler: Very nice if you need to quickly cover passbys. You can control it independently or attach it to the main Revs knob. Passby presets are already created for each vehicle which is very handy.

General Workflow

In terms of workflow, Igniter allows you to create the engine RPM movements in a very quick and flexible way and of course, you can always come back and tweak the automation to make it work better. Additional passes controlling other parameters (like load) can add extra realism and detail.

The loops are nice to have since you can, for example, make any car go on gravel or dirt, for example, with just adding a loop layer to the granular. The one shots are not that useful, in my opinion, since you can only have five individual sounds and you can’t assign probability or playlists to the triggers, so every time you pass through them on the RPM curve, you would hear the same exact sound. The way it works right now, I think you would be better of just editing sweeteners like skids manually on your DAW the old-fashioned way and use Igniter for the engine itself but I’m open to be wrong about this.

You would probably need two instances of Igniter, one for exterior shots and one for interiors, unless you want to do the interior treatment outside. Once you have the basic RPM behaviour down, you would then need to mix it into the scene with fader work, pan and distance attenuation. That’s why I was thinking that it would be cool to have a dedicated master distance knob so you can tweak this in one go once you find a reverb that works with the scene. With these system I’m imagining, you would do an RPM pass, a distance pass, some tweaks here and there and you would be done for that car. Rinse and repeat.

Lastly, it’s also important to mention that Igniter offers a multi output so you can get an individual signal from each layer and mix them in any way you want in your DAW. This is very much appreciated.

Is Full Tank worth it?

Krotos offers an expanded version called “Igniter Full Tank” which includes all the unprocessed and processed recordings used to build all the presets. You get a lot of coverage for every vehicle in Igniter plus loads foley and sweeteners. The recordings are a great library just by themselves (75 GB of additional audio) and in combination with Igniter will allow you to cover every single detail and sound you may need. To clarify, these extra sounds come as separate audio that you can then browse within Igniter, but they don’t include new presets or vehicles.

Conclusion

I hope both you and me now have a good understanding of how Igniter works and what it can offer. I had a lot of fun testing the plugin, Krotos keeps giving us innovative tools to create custom, unique soundscapes and I feel that with them we can offer much more value to our clients because the result is unique and personal.

Above all, the granular system sounds great and I know how hard is to make interactive engines sound good. I’m sure more content will come for the plugin in the future and maybe some workflow quirks will be fixed with time. As for the features I’ve been suggesting, they are just my own take on how I would improve the software’s workflow and capabilities and since I’m sure some concepts and perspectives have escaped me, I will remain open to new and better ways of using Igniter as it spreads across studios worldwide.

Thanks for reading!

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Exploring Sound Design Tools: Igniter