Spatial audio
8 perimeter PA + ~15 exciters; proto starts at 2 PA.
Engineering
Spatial audio — hybrid PA + exciters planned
Continuous spatial from elevated perimeter PA; contact impact from
tactile exciters on modular obstacles. One Audio Controller (not Unity) mixes UDP from the gateway.
Canonical: docs/REAL_ARENA.md § Spatial Audio.
v1 target (scalable from proto)
| Layer | Hardware | Role |
|---|---|---|
| Airborne / continuous | 8× Behringer B112D (or equiv.) @ ~1.5–2.5 m (proto: 2) | Whoosh, cast roar, ambience, announcer |
| Contact / local | ~15 exciters (1 / modular obstacle) | Impact bang + haptic |
| Exciter drive | Obstacle ESP32 + Class-D (smart-block pattern) | Gateway event by auto-mapped id |
| Controller | 1× Pi 5; USB stereo → UMC1820 / DAC8× | Inverse-square mix for N channels |
Prototype first
~12–20k CZK: 2 PA + 1 Pi + DAEX25 + DAEX32 + Class-D.
Success: <50 ms, pan across 2 PA, exciter↔LED sync, same binary for speakers: 8.
Rejected for v1
~30× Pi stream endpoints per wall (Dante/AVB fleet). Worse ops/cost; not better airborne quality than PA. Escape hatch only after hybrid immersion tests fail.
Latency & ports
Position → audio < 50 ms. Gateway :4120 (XYZ 30–60 Hz), :4121 (spell/impact). Full v1 audio line ~75k CZK inside ~324k CAPEX (no DMX).
Phase 3
Optional expand toward 16 PA; admin calibration UI; optional local LLM+TTS commentary.