# Windows Audio Setup — It Just Works

## Why this is short

Windows has a built-in feature called **WASAPI loopback** that lets an app capture whatever your system is playing — Spotify, your browser, a game, anything — without any virtual audio driver, cable, or routing setup. Conductør uses this automatically.

That's it. There's no install. There's no setup. Pick **Auto-detect loopback** in the Audio Input dropdown and play some music.

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## If audio reactivity isn't working

A few things to check:

1. **Audio Input is set to "Auto-detect loopback" or "System audio (loopback)".** Open the dashboard → Settings → Audio Input dropdown. If you've previously picked a specific microphone or device, switch back to the loopback option.
2. **Something is actually playing.** Sounds obvious, but the level meter only moves when there's signal. Open Spotify, YouTube, anything — verify you can hear it through your speakers/headphones first.
3. **Check the level meter.** Below the dropdown there's a live level meter. If it's bouncing, audio is reaching Conductør and the issue is downstream (fixture wiring, scene picked, etc.). If it's dead flat, the loopback isn't capturing — see next step.

## Edge cases

**Nothing is playing through my "default" output device.**
WASAPI loopback captures whatever Windows considers the default playback device. If you've routed audio to a different device (a USB DAC, an HDMI receiver, Bluetooth headphones) and it's *not* set as the system default, loopback won't see it. Open **Settings → System → Sound → Output** and confirm the right device is set as default.

**I'm using exclusive-mode audio (some DAWs, audiophile playback apps).**
Exclusive-mode locks the device for one app at a time. While that app holds the device, WASAPI loopback can't share. Switch the app to shared-mode output (most apps have this in their audio preferences) or pick a different output device.

**My laptop has Realtek audio with weird drivers.**
On rare older Realtek-only systems, WASAPI loopback can fail to open. Update Realtek drivers via **Device Manager → Sound, video and game controllers → Realtek → Update driver**. If that doesn't help, you can fall back to picking **Stereo Mix** from the dropdown (Settings → Sound → More sound settings → Recording → enable Stereo Mix first).

**I want to capture *one specific app's* audio, not the whole system.**
WASAPI loopback is system-wide — it captures the default output mixed with everything playing. For per-app capture, install **VB-CABLE** (a virtual audio cable) and route just that app's output to it; then pick VB-CABLE from the Audio Input dropdown. This is power-user territory and not needed for typical music-driven lighting.

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## Reference

- WASAPI loopback overview: <https://learn.microsoft.com/en-us/windows/win32/coreaudio/loopback-recording>
- VB-CABLE (optional, for per-app capture): <https://vb-audio.com/Cable/>
