diff --git a/app/static/js/app.jsx b/app/static/js/app.jsx
index ceabb79..35dabe8 100644
--- a/app/static/js/app.jsx
+++ b/app/static/js/app.jsx
@@ -1827,6 +1827,8 @@ async function fxRtStart() {
     };
     const fxRtInPump = () => {
       if (!fxRt.inQueue.length) return;
+      // Không còn dùng (gửi ngay theo đồng hồ audio — xem onmessage 'in').
+      // Giữ tham chiếu phòng khi track path còn dùng pattern cũ.
       const now = Date.now();
       while (fxRt.inQueue.length && now - fxRt.lastInSent >= FXRT_BURST_MS) {
         fxRt.lastInSent = now;
@@ -1868,8 +1870,12 @@ async function fxRtStart() {
         return;
       }
       if (d.type !== 'in') return;
-      fxRt.inQueue.push(d);
-      fxRtInPump();
+      // Gửi NGAY, không pace setTimeout: input pacing = đồng hồ audio worklet
+      // (1 frame/21.33ms), không phải timer main-thread. Timer bận/trễ → input
+      // gửi trễ → engine/bridge chỉ sản xuất output khi có input → cushion cạn
+      // dần → crackle sau 3-4s (đã xác nhận với chain RỖNG). Burst sau stall:
+      // engine hấp thụ (in ring 4 slot, bridge drain ~1ms, drop-oldest an toàn).
+      fxRtSendFrames(d);
     };
     // Pace input: tối đa 1 block/kỳ (~5.8ms). Gửi dồn theo burst (main thread bị
     // rAF renderFrame block khi mở MASTERING PANEL) → SHM ring 4-slot tràn → mất
diff --git a/app/static/js/app.precompiled.js b/app/static/js/app.precompiled.js
index 683eeff..a3fa88c 100644
--- a/app/static/js/app.precompiled.js
+++ b/app/static/js/app.precompiled.js
@@ -318,7 +318,7 @@ const fxRtSendFrames=d=>{if(!fxRt.ws||fxRt.ws.readyState!==1)return;try{const f=
 // chong race: neu stop/restart xay ra trong luc cho, bo qua.
 if(fxRt.fadedIn)return;setTimeout(()=>{if(token!==fxRt.startToken)return;fxRt.fadedIn=true;fxRtCrossfade(true,token);// Dry gan silent (tc 0.025) roi moi tre pdcDelay — tranh gap khi delay
 // dang lon dan.
-setTimeout(()=>fxRtApplyPdc(),250);},30);return;}if(d.type==='set_param'){try{fxRt.ws.send(JSON.stringify({cmd:'set_param',slot:d.slot,key:d.key,value:d.value}));}catch(e){}return;}if(d.type==='stats'){fxRt.stats=d;console.debug('[FX RT stats]',d);return;}if(d.type!=='in')return;fxRt.inQueue.push(d);fxRtInPump();};// Pace input: tối đa 1 block/kỳ (~5.8ms). Gửi dồn theo burst (main thread bị
+setTimeout(()=>fxRtApplyPdc(),250);},30);return;}if(d.type==='set_param'){try{fxRt.ws.send(JSON.stringify({cmd:'set_param',slot:d.slot,key:d.key,value:d.value}));}catch(e){}return;}if(d.type==='stats'){fxRt.stats=d;console.debug('[FX RT stats]',d);return;}if(d.type!=='in')return;fxRtSendFrames(d);};// Pace input: tối đa 1 block/kỳ (~5.8ms). Gửi dồn theo burst (main thread bị
 // rAF renderFrame block khi mở MASTERING PANEL) → SHM ring 4-slot tràn → mất
 // block → ngắt quãng.
 // Phase 4.2: fader SAU worklet — worklet chèn giữa outputAnalyser (chain
diff --git a/app/templates/index.html b/app/templates/index.html
index 0b3bf9e..78502db 100644
--- a/app/templates/index.html
+++ b/app/templates/index.html
@@ -51,7 +51,7 @@
     <script src="/static/js/services/promptTemplateManager.js?v=202607281039"></script>
     <script src="/static/js/services/undoRedoEngine.js?v=202607290941"></script>
     <script src="/static/js/services/chordTheory.js?v=202608211300"></script>
-    <script src="/static/js/app.precompiled.js?v=202608241203" defer></script>
+    <script src="/static/js/app.precompiled.js?v=202608242100" defer></script>
     <link rel="stylesheet" href="/static/css/styles.css?v=202607271016">
     <style>
         :root {