diff --git a/app/core/vst_engine.py b/app/core/vst_engine.py
index d8adb6b..2bb0420 100644
--- a/app/core/vst_engine.py
+++ b/app/core/vst_engine.py
@@ -49,27 +49,29 @@ def render_midi_events_to_audio(midi_events: list, sr: int = 44100, bpm: float =
         out_r /= max_peak
     return np.vstack([out_l, out_r])
 
-def check_pedalboard_safe():
-    import subprocess, sys
+def _module_available(name: str) -> bool:
+    """Kiem tra module co san khong — KHONG spawn subprocess.
+
+    Truoc day dung subprocess.run([sys.executable, '-c', 'import X']) —
+    khi app dong goi (PyInstaller frozen), sys.executable = daw_engine.exe
+    -> subprocess chay CA ENGINE (bootloader bo qua '-c', chay desktop_engine)
+    -> moi lan check lai sinh ra engine moi -> de quy spawn vo han
+    (Task Manager day daw_engine, port 8000-8005 leo thang, load rat cham).
+    find_spec() nhanh (micro-giay) va hoat dong ca source lan frozen.
+    """
+    import importlib.util
     try:
-        res = subprocess.run(
-            [sys.executable, "-c", "import pedalboard"],
-            stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, timeout=2.0
-        )
-        return res.returncode == 0
-    except Exception:
+        return importlib.util.find_spec(name) is not None
+    except (ImportError, AttributeError, ValueError):
         return False
 
+
+def check_pedalboard_safe():
+    return _module_available("pedalboard")
+
+
 def check_pyfluidsynth_safe():
-    import subprocess, sys
-    try:
-        res = subprocess.run(
-            [sys.executable, "-c", "import fluidsynth"],
-            stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, timeout=2.0
-        )
-        return res.returncode == 0
-    except Exception:
-        return False
+    return _module_available("fluidsynth")
 
 HAS_PEDALBOARD = check_pedalboard_safe()
 HAS_PYFLUIDSYNTH = check_pyfluidsynth_safe()
diff --git a/desktop_engine.py b/desktop_engine.py
index 5b010b3..67938c4 100644
--- a/desktop_engine.py
+++ b/desktop_engine.py
@@ -52,6 +52,13 @@ def _parent_alive(pid):
 
 
 def main():
+    # PHONG THU (fix ban 1.1.2): neu exe bi goi nhu 'python -c ...' — vd code
+    # cu kiem tra thu vien bang subprocess.run([sys.executable, '-c', 'import X'])
+    # thi frozen sys.executable = daw_engine.exe -> se chay CA ENGINE o day.
+    # Thoat ngay, KHONG khoi dong server, tranh de quy spawn vo han.
+    if len(sys.argv) > 1 and sys.argv[1] == "-c":
+        return
+
     os.environ.setdefault("SF_DESKTOP", "1")
 
     # Log dir tao SOM de stderr co the tro vao file (xem duoi).