The measurement thread from the retrospective never ended — it moved to Go. gll-tools is a Go library and a set of CLI tools for reading EASE GLL (Generic Loudspeaker Library) data, the format the pro-audio world uses to describe loudspeaker directivity and behavior.
From plugin analysis to loudspeaker data
Twenty years ago I measured VST plugins and averaged HRTF databases; today I work with loudspeaker and acoustic measurement data. The formats changed — GLL, SOFA, DAFF — but the discipline is identical: read the data faithfully, understand exactly what each number means, and build tools that let you look at it from every angle.
Standing on old code
This project has unusually deep roots in my own history. I wrote PasSofa, an Object Pascal reader for SOFA (Spatially Oriented Format for Acoustics) files, back in 2017 — and then ported it to JavaScript as WebSofa, along with an HDF library, because SOFA is HDF underneath. Even the little XL2-marker-shifter — a one-evening web tool that shifts markers in an NTi XL2 measurement file by a fixed offset — belongs to this thread: small, specific tools that remove one concrete annoyance from acoustic measurement work.
Why CLI tools?
The old measurement programs were Windows GUI applications. The new ones are libraries with thin CLI frontends, because that is what measurement work actually wants in 2026: scriptable, pipeable, automatable, runnable on a headless box next to the measurement rig. Go’s single-binary deployment is a perfect fit — copy one file to the machine and start working.