diff --git a/config/alarms.sample.json b/config/alarms.sample.json
index 35a890f..6fee120 100644
--- a/config/alarms.sample.json
+++ b/config/alarms.sample.json
@@ -9,5 +9,10 @@
     "alarm_time": "2330",
     "alarm_audio": "assets/alarm/sleep.wav",
     "alarm_image": "assets/img/sleep.png"
+  },
+  {
+    "alarm_time": "0800",
+    "alarm_days": ["Sat", "Sun"],
+    "alarm_image": "assets/img/on_alarm.png"
   }
 ]
diff --git a/contents_server.py b/contents_server.py
index 554d144..d89e8ac 100644
--- a/contents_server.py
+++ b/contents_server.py
@@ -48,12 +48,22 @@ def _resolve_path(relative: str) -> Path:
     return p
 
 
-def _prepare_alarm(entry: dict) -> dict:
+def _prepare_alarm(entry: dict, audio_cache: dict[Path, tuple]) -> dict:
     """Pre-resolve paths and load resources for a single alarm entry."""
-    audio_path = find_wav(_resolve_path(entry.get("alarm_audio", "assets/alarm/alarm_test.wav")))
     alarm_img_path = _resolve_path(entry.get("alarm_image", "assets/img/on_alarm.png"))
-    pcm, sr, ch, bits = read_wav(audio_path)
     img = load_status_image(alarm_img_path)
+
+    pcm = sr = ch = bits = None
+    raw_audio = entry.get("alarm_audio")
+    if raw_audio is not None:
+        audio_path = find_wav(_resolve_path(raw_audio))
+        if audio_path in audio_cache:
+            log.info("Reusing cached audio for %s", audio_path)
+            pcm, sr, ch, bits = audio_cache[audio_path]
+        else:
+            pcm, sr, ch, bits = read_wav(audio_path)
+            audio_cache[audio_path] = (pcm, sr, ch, bits)
+
     return {
         "config": entry,
         "pcm": pcm, "sr": sr, "ch": ch, "bits": bits,
@@ -71,7 +81,8 @@ async def handler(ws):
     img_idle = load_status_image(IMG_DIR / "idle.png")
     current_img = img_idle
 
-    alarms = [_prepare_alarm(entry) for entry in configs] if configs else []
+    audio_cache: dict[Path, tuple] = {}
+    alarms = [_prepare_alarm(entry, audio_cache) for entry in configs] if configs else []
 
     async def alarm_ticker():
         nonlocal current_img
@@ -91,10 +102,14 @@ async def handler(ws):
                                  alarm["config"]["alarm_time"], current_minute)
                         current_img = alarm["img"]
                         await send_status_image(ws, current_img)
-                        await stream_alarm(ws, alarm["pcm"], alarm["sr"],
-                                           alarm["ch"], alarm["bits"])
-                        # let the image persist a bit more
-                        await asyncio.sleep(1)
+                        if alarm["pcm"] is not None:
+                            await stream_alarm(ws, alarm["pcm"], alarm["sr"],
+                                               alarm["ch"], alarm["bits"])
+                            # let the image persist a bit more
+                            await asyncio.sleep(1)
+                        else:
+                            # longer image persistence when no audio
+                            await asyncio.sleep(10)
                         current_img = img_idle
                         await send_status_image(ws, current_img)