diff --git a/pysonic/api.py b/pysonic/api.py
index b3dea97..c17745f 100644
--- a/pysonic/api.py
+++ b/pysonic/api.py
@@ -189,8 +189,9 @@ class PysonicSubsonicApi(object):
 
     @cherrypy.expose
     def stream_view(self, id, maxBitRate="256", **kwargs):
-        maxBitRate = int(maxBitRate)
-        assert maxBitRate >= 32 and maxBitRate <= 320
+        maxBitRate = int(maxBitRate) or 256
+        if maxBitRate < 32 or maxBitRate > 320:
+            raise cherrypy.HTTPError(400, message=f"invalid maxBitRate: {maxBitRate}. Must be between 32 and 320.")
         song = self.db.get_songs(id=int(id))[0]
         fpath = os.path.join(song["root"], song["file"])
         media_bitrate = song.get("bitrate") / 1024 if song.get("bitrate") else 320