Util/Audio/Mixer/VoiceMixer.cs

@@ -75,8 +75,11 @@ internal sealed class VoiceMixer : IDisposable
     /// <summary>Voices currently mixed (started or waiting to start). Render thread only.</summary>
     public int ActiveVoiceCount => _voices.Count;
 
-    /// <summary>Output sample nearest to <paramref name="seconds"/>.</summary>
-    public static long ToSample(double seconds, int rate) => (long)Math.Round(seconds * rate, MidpointRounding.AwayFromZero);
+    /// <summary>
+    /// Output sample containing <paramref name="seconds"/> (seconds × rate rounded down), the sample at which
+    /// AudioSource.PlayScheduled starts a sound scheduled between two output samples.
+    /// </summary>
+    public static long ToSample(double seconds, int rate) => (long)Math.Floor(seconds * rate);
 
     // ── Main thread ──