diff --git a/simulator/static/app.js b/simulator/static/app.js
index e2aedf4..ed3eb9b 100644
--- a/simulator/static/app.js
+++ b/simulator/static/app.js
@@ -1192,7 +1192,10 @@ function scaleAudioUrl(index) {
   if (!ring || !ring.scales.length) return null;
   const s = ring.scales[HEFScrub.wrapIndex(index, ring.scales.length)];
   const a = s.audio || SCALE_AUDIO_FALLBACK[s.id];
-  return a ? "/media/audio/" + a : null;
+  // Route through mediaBase() so audio loads from R2 in the static build (and the
+  // local /media mount in dev) — NOT a hardcoded /media path, which 404s on the
+  // static site. mediaUrl() then passes this absolute url straight through.
+  return a ? mediaBase() + "audio/" + a : null;
 }
 // The current resting altitude's soundtrack url (kept for the status readout).
 function soundtrackUrl() { return scaleAudioUrl(ringIndex); }