How to Trigger ETC Eos Cues from Live Audio

Why Eos Is the Easy One

Automating a lighting console usually means finding out which of several half-documented control surfaces the vendor expects you to use. Eos is the exception: OSC is native, documented, and switched on from the console.

Setup → System → Show Control → OSC. Enable RX and TX, note the IP and port. That is the whole console-side configuration. No plugin, no middleware, no macro scaffolding in the show file, and nothing that has to be re-done when the show file changes.

Which means the interesting question is not how do I connect but what should I send.

The Command Surface

Three details in that table are worth stating explicitly, because each one is a bug someone has already shipped.

The Go key is not a cue fire. /eos/key/go_0 is the operator's Go button: it advances the active cue list from wherever it currently sits. /eos/cue/<list>/<number>/fire jumps to a named cue regardless of position. Sequential playback wants the first. Event-driven triggering that must land on a specific look wants the second. Using Go where you meant an explicit fire produces a show that is correct in rehearsal and wrong the first time anything runs out of order.

Submasters take a float argument, on /eos/sub/<number> — the level is the argument, not part of the address. This is the form that maps cleanly onto a continuous audio parameter.

Macros fire on /eos/macro/<number>/fire. An older form, /eos/macro/fire/<number>, appears in circulated examples; the argument form /eos/macro/fire with the number as an argument is equivalent. Pick one and be consistent.

One more, easily missed: /eos/key/sneak is a valid key and an unrelated function. It is not a pause. Pause is /eos/key/stop.

Discrete Cues or Continuous Levels

Two different mappings, and most shows want both.

Discrete — fire a cue. A drop, a section change, a phrase boundary. The console owns the look; the trigger only decides the moment. This is where beat-phase accuracy matters, because a cue that lands a beat late reads as a mistake rather than a design.

Continuous — drive a level. Route an energy envelope or a frequency band to /eos/sub/<number> and the rig moves between programmed states rather than stepping between them. This is what makes automated lighting look intentional instead of mechanical, and it costs nothing on the console beyond having submasters to drive.

A show built only from cue fires looks like a slideshow. A show built only from levels never lands a moment. The combination is the point.

Reading the Console Back

Eos also transmits. It publishes the active cue on /eos/out/active/cue/... and the show name on /eos/out/show/name.

This matters more than it first appears. A controller firing cues blind accumulates a belief about console state that drifts from reality the moment anyone touches the desk — and on a real show, someone always touches the desk. Subscribing to the outbound feed lets a controller reconcile what it thinks is active against what actually is.

CueSync uses exactly this feed for cue reconciliation, parsing /eos/out/active/cue/... to keep its own view aligned. The equivalent on GrandMA3 is that console's OSC-out configuration; the principle is the same, and a controller that does not do it will eventually fight the operator.

What This Does Not Do

It does not program the desk. Every cue fired here was built by someone in the console, and the console remains the source of truth for what a look is. The automation layer decides when, never what.

That boundary is what makes it usable on a real production. On a show with no dedicated Eos operator, this can drive the desk end to end. On a programmed show, it fires the automated cues while an operator keeps a hand on manual override — and because Eos is receiving ordinary OSC rather than being remote-controlled at a lower level, the operator's actions always win.

Setup, End to End

1. On the console: Setup → System → Show Control → OSC. Enable RX and TX. Note the IP and port.
2. In CueSync: add an Eos OSC output pointed at that IP and port.
3. Map triggers — beat, phrase, energy, timecode, or manual — to cue fires, Go, channels, submasters, or macros in the routing editor.
4. Validate before the rig is live. Full configuration is available without a subscription, so the wiring can be proved on a bench.
5. Test with ETCnomad on a loopback if the console is not available yet. The OSC surface is identical.

Compatible systems: Eos Ti, Gio, Gio @5, Ion Xe, Element 2, ETCnomad, Nomad Puck — any Eos system that exposes OSC.

Further Reading

• Audio-Reactive Cues Over OSC — the same idea aimed at QLab
• What Is Music-Driven Lighting Automation? — the category, from the top
• ETC Eos Integration — command surface, compatibility, setup steps
• CueSync for Theatre Operators — cue stacks, Show Editor, Run Mode

ETC® and Eos® are trademarks of Electronic Theatre Controls, Inc. CueSync is an independent product and is not affiliated with or endorsed by ETC.