Inside Biquadia: On-Device Audio Lab

Biquadia began with a simple tension: professional audio tools are powerful, but they often assume a studio desk, a laptop, and time to configure the environment. The phone already has microphones, accelerometers, serious compute, and an extraordinary display. What would an audio laboratory look like if it began there?

The answer was not to shrink desktop software. It was to build around the device’s actual strengths.

Real time changes everything

Audio code has a hard deadline. If a frame arrives late, the interface cannot hide it with a loading state. The result is audible.

That constraint shaped the architecture: a focused native interface around a C++ DSP core, careful separation between real-time work and presentation, and measurement tools that remain useful without destabilizing the signal path.

Privacy as an architectural choice

Microphone data is unusually intimate. Biquadia processes it locally and keeps analysis on-device. That decision reduces the surface area of the system while making the product more trustworthy.

It also makes the experience more immediate. No upload, no round trip, no dependency on a server remaining available. The instrument responds because the instrument is already in your hand.

A tool should invite depth

Biquadia is technical by design, but technical does not have to mean hostile. The interface exposes serious concepts—spectra, filters, spatial processing, dynamics—through a system meant to reward exploration.

The larger experiment is whether expert capability and a welcoming surface can occupy the same product. Biquadia is our current answer.

Want to see the frequency-domain math behind that spectral view without opening the app? The Fourier epicycles playground runs the same discrete Fourier decomposition on a 2D drawing instead of an audio signal — draw a shape, watch it resolve into the same rotating-circle frequency components. And for the DSP core itself, the biquad filter designer reproduces the exact Direct-Form-II-Transposed filter Biquadia ships, with a live Web Audio preview.

For real-world hardware applications of Biquadia, see our field builds: real-time acoustic beamforming on an iPhone with the miniDSP UMA-8 and measuring headphone response with a binaural dummy head and multimeter.