Before Gumilang was tuning reflections and modal resonances for a living, he was just a kid in a band trying to sound good. Fast forward a few years and he’s still chasing sound, just with fancier tools now.
Let’s start from the beginning. How did music find its way into your life?
It goes back to junior high. Gumilang played in a band, sang in a choir, and was always paying way more attention to what he was hearing than the average listener. Once he got to university, that curiosity turned technical. He got into audio engineering, learning how to mix vocals and instruments, and still helps friends out with side mixing projects whenever he gets the chance.
And how did that turn into a career in acoustics?
He studied Engineering Physics, and it just so happened the Building Physics lab there had an acoustics division. That was enough to hook him. Two things he already loved, physics and music, suddenly overlapped. He locked in early, carrying that focus from his bachelor’s straight into his master’s. An acoustic consultant role opened up, and that was his way in. By the time he joined Soundzipper, acoustics wasn’t something new to learn. It was already the thing he did.
What does a typical day look like for you now?
Simple start: toast and a pot of tea, then email and calendar. After that it’s a mixed bag. Some days are consultation and acoustic documentation. Some are testing, taking measurements on-site, then crunching the data into a report. There’s also design and build work like studios and cinemas, where he sets the technical direction and figures out materials, then briefs it to Caesaria, who turns it into SketchUp 3D or 2D models. For simulation, the team runs Olive Tree Labs to model room acoustics and environmental noise before anything actually gets built.
Any project that really stuck with you?
Jack’s home theatre, easily. Jack wanted a home cinema built to Dolby-certified standards, which meant 27 speakers and 8 subwoofers packed into a single 6×7 metre room. The hard part wasn’t just the scale of it. Everything had to be genuinely professional-grade, luxurious, zero distortion, and able to hit max output without ever sounding strained.
What’s the culture like at Soundzipper, from where you sit?
The team is small, and that changes everything. Everyone has a clear role and real freedom in how they get things done, as long as they deliver. For Soundzipper, that freedom is actually a way of looking out for the team. Give people room to work how and where they work best, and they execute faster and deliver results that make clients happy. That’s the bet, and Gumilang says it pays off. Between the Indonesian and Singapore teams, there’s a strong sense of “we’ve got each other” that makes the whole thing click.
Where do you want to grow in the next few years?
He just wants to keep learning. Acoustics is a field where something new is always surfacing, a product, a technique, a new answer to an old client problem. Lately what he’s most drawn to is field implementation. Every project teaches him something about whether a design actually survives contact with reality. Can the contractor actually build what’s on the drawing? What else in the building is going to fight it, the AC, the electrical routing? Where does the AC unit go, where does the silencer go? That gap between the drawing and the finished room is where the real learning happens.
Bonus fact: Gumilang’s physics brain gives him strong opinions about sci-fi. He’ll tell you Christopher Nolan’s Interstellar is one of the few that actually gets the science right, which is a pretty high bar coming from someone who models sound waves for fun.