The Utrecht Synth Whisperer: A Deep Dive with Allert Aalders of Sonar Traffic

Deep in the woods near Utrecht, inside a space that started as a shared synthesizer playground and evolved into a world-class sound-design workshop, you’ll find Sonar Traffic. Housed in a former anti-squat building run by ‘stichting Klank’, the studio breathes with the warm, metallic scent of vintage circuits and the low-frequency hum of a hundred oscillators.

This is the sanctuary of Allert Aalders, a man whose DNA is interwoven with the history of electronic music. A veteran of the 90s techno act Human Beings, Allert toured Europe during the genre’s foundational years. Today he designs presets and sounds for brands like native instruments, arturia, korg, kilohearts and offers synthesis workshops and meetups. He’s also part of the Dutch Modular Fest crew and organizer of Modulation Utrecht. We spent an afternoon with Allert at Sonar Traffic to discuss his journey into synthesis, the emotional story behind some of his inherited equipment, his work as a sound designer and some helpful advice to beginners.

The Journey: From Punk to the 909

Allert, you didn’t start out as a “synth guy.” How did your ears first find their way to electronic music?

It started with listening. In my early years, I moved from mainstream rock and punk toward bands that used “abnormal” instruments: synths, keyboards, and sequenced parts. I was drawn to how moldable electronic sound was compared to acoustic instruments. I dipped into the experimental and industrial scenes, noise and harsh textures, where it was more about pushing sound until it revealed something new.

Then house and techno hit. That was the “proof” that these machines weren’t just weird art objects; they could carry energy and community. I actually started on drums, but I was terrible at practicing. I sold my kit and bought a small synth with drum parts just to reduce the friction of making music. At the time, I was running a basic Atari setup with Cubase.

How did you get your hands on the 909?

I recognized the sound of house music instantly in the 909. But back then, magazines called it a “failed” drum computer because it didn’t sound like “real” drums. I saw one in a shop window for 300 guilders. My bank account said I had exactly 300 guilders for the rest of the month. I didn’t hesitate. I bought it and lived on nothing for weeks.

The Legacy of Human Beings and the Birth of Sonar Traffic

You were a core part of Human Beings. How did you transition from a bedroom studio to playing massive stages?

Our home base was Ekko, a Dutch club that was more of a youth center than a fancy venue. I’d set up my 909 next to the DJ desk and borrow a friend’s sequencer that could handle multiple tracks. We were testing sounds in real-time on a heavy PA.

One night at Echo, a tall man approached me and invited me to join Human Beings. Our setup was pure improvisational spirit: an array of synths and drum machines running into a mixing desk, where we’d perform by muting, unmuting, and shaping patterns live. We toured all over the Netherlands, Germany, Belgium, Prague; often solving logistical nightmares through sheer community support.

The studio today feels like a continuation of that era. How did the concept for Sonar Traffic actually begin?

The spark came from Hamburg. I visited a club called Uebel & Gefährlich, located inside a massive bunker. Behind a wardrobe door, there was a room overflowing with gear like the Jupiter 8, ARP Quadra and all these incredible synths that people could rent. I asked myself: “Could I do something similar in Utrecht?”

When I pitched it to my partner Ben Spaander (Cosmic Force), he was all in. We pooled our collections, but we soon realized that a traditional rental business is a nightmare. Vintage gear is fragile. Eventually, the studio evolved into what it is now: Sonar Traffic, a workspace dedicated to professional sound design and, most importantly, teaching the next generation of synthesists.

The Gear: The emotional background behind the Synton Syrinx

Standing in this room, the red Synton Syrinx immediately catches the eye. Why is that instrument so significant?

The Synton Syrinx is a Dutch masterpiece built right here in Utrecht. Only 300 were ever made. My unit is one of a handful produced in red, but its value isn’t monetary, it’s an inheritance. It belonged to Bert (Human Beings), who passed away in 2005. It has a unique filter design with two extra resonant peaks that give it this “throaty,” vocal character. Despite the insane offers I get, it will never leave Sonar Traffic. To me, the gear isn’t just hardware; it’s the physical presence of the friends who are no longer here.

Education: Modular Synthesis Workshops at Sonar Traffic

You’ve become a pillar of the community through your workshops. Why is teaching such a big part of your mission now?

I want to demystify these machines. Many people see a modular wall and feel intimidated, but once you understand the “system,” it becomes an extension of your own creativity.

In my synthesis lessons, I use a Roland Jupiter 6 because it’s the perfect entry point. I don’t start with “super saws.” I ask students to emulate a violin. It forces them to think about transients and how a sound “trails off.” We use water analogies for signal flow and audio scopes to visualize the waves. Whether it’s a private lesson or our “Sonar Traffic Social Synth Saturdays,” the goal is to get people to stop using presets and start building their own sonic language.

Building the Scene: Modulation and Utrecht

You’ve been a massive advocate for the local scene. How did “Modulation” grow so quickly?

I started Modulation in 2015 as a place for modular livesets. We put tables in the middle of the room so people could see the gear and learn. The real evolution was the “tiny interviews”, asking artists about their process before they play. Today, the Utrecht scene is a thriving web of collectives like Acid Solder Club and Synth After Work. It’s about making electronic music accessible to everyone.

Professional Sound Design: From Superbooth to Arturia

You’ve designed sounds for Arturia, Native Instruments, and FabFilter. How does one turn a passion for patching into a career?

It started with visibility at Sonar Traffic. I got a call from a trailer music company called “the Solo’s” and I did a lot of sound design, like robot steps and weird sound effects for them. And the owner previously created presets for Native Instruments but didn’t really have the time to do that anymore so he asked me to help out. And so that ball started rolling which eventually led to other companies such as Arturia, Fabfilter, Korg, Kilohearts and the likes.

My biggest advice is networking at events like Superbooth, but also being patient. When you’re designing presets, you aren’t just making “cool sounds.” You’re building tools for other musicians. It requires a massive portfolio of “happy accidents” and a deep understanding of how different systems interact.

Final Advice: “Always Be Recording”

For the producer at home who is feeling overwhelmed, what is your most practical advice?

1. Always be recording. Don’t wait until the patch is “perfect.” The tinkering and the errors are where the best textures live. You can harvest those snippets later for film trailers or tracks.
2. Start with VCV Rack. If you’re on a budget, use free virtual modular tools to learn the logic before spending thousands on hardware. Also check out Reaper which is an incredible DAW which is very affordable.
3. Find your own process. Legends don’t emulate; they innovate. Find something that sounds weird to you, extend it, and make it your own.

Ready to Master Modular Synthesis?

If you’re looking to take your sound design to the next level, there is no better place than Sonar Traffic. Allert Aalders offers specialized workshops and private lessons that cater to all skill levels, from total beginners to experienced producers.

Visit the Sonar Traffic Website to Sign Up for his Workshops

Keep an eye on Allert’s socials for the next “Social Synth Saturday” and go visit Dutch Modular Fest or Modulation when you’re in the area.