How to Fix Music Not Ducking Under Dialogue in Unreal Engine

Voiceover plays at full volume over the music with no automatic dip. Unreal only ducks when a Sound Mix that lowers the music class is actually pushed or triggered.

How to fix it

1. Use a passive Sound Mix

On the Dialogue Sound Class set a Passive Sound Mix Modifier that targets the Music class with a lower volume and a low trigger threshold so any VO activates it.

2. Or push the mix in code

Call PushSoundMixModifier with a duck mix when dialogue starts and PopSoundMixModifier when it finishes for precise control.

3. Lower the threshold

If ducking never fires, the passive mix's min volume threshold is too high; quiet VO never crosses it. Lower the threshold so it triggers reliably.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Unreal Engine error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.