Introducing Orbit Core — The Spatial Audio Engine Behind Everything We Build

The Engine at the Heart of It

Every product we ship at South Loop Studios — whether it runs in a browser tab or on a Mac — shares the same audio DNA. That DNA is Orbit Core: a high-performance spatial audio rendering engine written in C++ and designed from day one to power real-time 3D audio on any platform we choose to target.

The Orbit Core Logo

Orbit Core is the technology beneath the products you use — and it now ships as an SDK. When Esfera renders an immersive mix live in your browser, Orbit Core is doing the work. When Orbit Spatial® plays back an ADM master with per-object binaural rendering and head tracking on macOS, Orbit Core is doing the work. One engine, multiple surfaces, zero compromise on audio quality.

Why Build Our Own Engine?

Spatial audio is a hard problem. Binaural rendering, HRTF processing, head tracking integration, channel-bed panning, object-based mixing — each of these is complex on its own. Combining them into a single pipeline that runs in real time, at low latency, across fundamentally different platforms (native C++ on macOS and WebAudio in the browser) demanded a purpose-built solution.

Off-the-shelf options either locked us into a single platform, imposed unacceptable latency, or lacked the rendering fidelity we needed. So we built Orbit Core to give ourselves full control over the spatial audio pipeline — from source input to binaural output.

What Orbit Core Does

At its core (no pun intended), the engine handles:

• ADM loading and playback — drag-drop ADM BWF files, programme switching, and multi-bed audio management.
• Binaural rendering — high-quality HRTF-based spatialisation that places audio objects convincingly in 3D space around the listener.
• Head tracking integration — rotation data from AirPods, camera-based tracking, or external IMUs updates the listener orientation in real time, keeping the sound field stable as you move.
• IAMF encode/decode — full support for the Immersive Audio Model and Formats specification.
• Loudness analysis and calibration — ITU-R BS.1770 metering built into the pipeline.
• Object-based audio processing — individual audio objects with independent position, gain, and metadata, rendered per-frame according to ADM or proprietary scene descriptions.
• Channel-bed support — standard bed formats (stereo, 5.1, 7.1.4) decoded and rendered alongside discrete objects.
• Cross-platform abstraction — the same core compiles natively for macOS (direct CoreAudio HAL, no JUCE) and targets WebAudio via WebAssembly.

The OrbitCore SDK

Orbit is now built on the same OrbitCore SDK we’re shipping to developers. The API is typed Swift with dot-notation — no C structs, no unsafe pointers. A minimal integration is four lines:

let engine = OrbitEngine()
engine.adm.load(url: admFileURL)
engine.audio.start()
engine.transport.play()

ADM playback, programme switching, IAMF encode/decode, HRTF binaural, loudness, head tracking, mixing, calibration — it’s all there, all typed, all clean. Every feature you see in Orbit Spatial® talks to that same surface. Commercial licenses are available — get in touch to discuss integration.

Powering Esfera

Esfera is the world’s first dedicated spatial audio streaming platform. It renders immersive audio live in the browser — no plugins, no apps, no special hardware. Behind the scenes, Orbit Core compiled to WebAssembly drives the entire rendering pipeline. Head tracking, binaural spatialisation, and real-time scene updates all run client-side at interactive frame rates. The fact that this works reliably in a browser tab is something we are genuinely proud of.

Powering Orbit Spatial®

Orbit Spatial® is our collection of tools and solutions for spatial audio QC and production. From ADM quality control and VAMP export to video sync and per-object monitoring, Orbit Spatial® covers the full immersive audio production chain. As of v1.4.2, Orbit is built entirely on the OrbitCore SDK — the same API surface that ships to third-party developers. It runs on direct CoreAudio HAL integration (JUCE-free), giving us full control over audio routing and hardware I/O with minimal latency.

R&D First

Orbit Core is where our research lives. New HRTF models, improved interpolation techniques, latency reduction strategies, perceptual optimisations — all of it lands in the engine first, then propagates to every product built on top of it. This architecture means that when we improve rendering quality or add a new capability, Esfera and Orbit Spatial® both benefit immediately.

We treat the engine as a long-term investment. Spatial audio technology is still evolving rapidly, and having a shared, well-understood core gives us the flexibility to move fast without rebuilding from scratch every time the landscape shifts.

Learn More

Orbit Core is the foundation of everything we build at South Loop Studios. If you want to understand the technology behind Esfera and Orbit Spatial®, or if you are interested in what we are working on next:

• Orbit Core overview: esfera.audio/orbitcore
• Try Esfera: esfera.audio
• Orbit Spatial®: orbitspatial.io
• Talk to us: Contact South Loop Studios