diff --git a/voice.py b/voice.py
index 99b5a34..9cd5031 100644
--- a/voice.py
+++ b/voice.py
@@ -256,10 +256,10 @@ class VoiceSession:
                         break
                     await asyncio.sleep(0.1)
 
-            # Connect in per-participant mode (empty shared_key) so Rust FFI uses
-            # identity-based HKDF — matching Element Call's JS SFrame key derivation.
-            # Keys are set post-connect via set_key(identity, key, index).
-            e2ee_opts = _build_e2ee_options()
+            # DIAGNOSTIC: disable E2EE entirely to check if EC sends encrypted or plaintext.
+            # If VAD triggers → EC sends plaintext (E2EE disabled on EC side).
+            # If VAD silent → EC sends encrypted (frame format or key issue).
+            e2ee_opts = None  # TODO: re-enable after diagnosis
             room_opts = rtc.RoomOptions(e2ee=e2ee_opts)
             self.lk_room = rtc.Room()