Dubler by Vochlea

Built with Qt

From your voice to the computer with Dubler, Vochlea's real-time voice-to-midi controller

15x faster

development speed with QML

Stable 60 fps

low-latency UI to display audio processing

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Make more of the music you love without worrying about how to get your ideas into your DAW. Dubler 2 transforms your voice into a real-time MIDI controller, allowing you to write music at the speed of thought. If you can sing it, beatbox it, hum it, or whistle it— now you can play it.

From your brain to your song!

Dubler is a magnificent piece of software for musicians. Do you have a melody in your head but don’t know how to play it? Instead of recording your tune in a voice note, you can now hum or sing that idea straight into your DAW with real-time voice-to-MIDI notation.

Dubler can generate beats and melodies as well as advanced chords. You can lock your notes to any scale you want.

You can trigger drum samples instantaneously by making any percussive sound— beatboxing, clicking, or clapping. Dubler even tracks the velocity of your voice giving you complete control over your beat.

Development challenges

Creating an appealing and responsive UI alongside professional, resource-hungry music-making software
Limited development time
Limited budget

How Qt Helped

Low-latency C++ for audio development for speed and efficiency
QML to easily and quickly declare complex and efficient frameworks
Hardware-acceleration out-of-the-box

"QML is by far my favourite thing about Qt. It’s one of the best languages that I’ve ever used. It takes only a few days to get the hang of QML. It’s quite common to take months or years to get good at a language. It’s really productive, it’s really fast, it saves lots of time, it’s a joy to use."

Daven Sanassy, CTO, Vochlea

How Vochlea created Dubler's lightning-fast and beautiful-looking QML desktop user interface

To build Dubler, the smart people at Vochlea cherry-picked from different development frameworks. Juce, for instance, is the de-facto framework for low-latency, high-speed audio processing. A full-stack framework in its own right, it can also produce user interfaces in C++ and OpenGL.

One of Vochlea's challenges was that Dubler had so much going on under the hood, but they still needed to create a user interface that

is fast enough to display audio processing in real-time
represents all the features of a complex backend in a user-friendly manner
wouldn't take months to design, develop, and iterate in C++
looks snazzy

The reason Vochlea chose Qt for Dubler's UI was QML. QML is a declarative development language that retains a high performance and compiles quickly. This way, they could create a complex UI almost 15 times faster than the alternative: "If I were to create a complex UI in C++ and OpenGL it would take me a week, I can produce the same thing in a few hours without much or any performance loss," says Vochlea's CTO Daven Sanassy about QML.

Vochlea also took advantage of the enhanced cross-platform capabilities in Qt 6, which allowed them to write their UI in QML, but compile it on macOS running on Metal, or on Windows running on Direct3D.

Qt's signals and slots architecture and property system simplified interfacing between C++ and QML by allowing their C++ developer to connect the backend data to the UI very quickly.

Other helpful aspects of Qt 6, like the quality of Qt's profiler, documentation, and ecosystem sped things along even further.

"Qt has an excellent property system and signals and slots architecture, that makes it really easy to interface between C++ and QML. It’s really natural for a C++ developer to work with and allows you to connect your data to your UI very quickly."