diff --git a/peak_det_eval.grc b/peak_det_eval.grc
index d8905a1..4b24213 100644
--- a/peak_det_eval.grc
+++ b/peak_det_eval.grc
@@ -463,7 +463,7 @@
     </param>
     <param>
       <key>cutoff_freq</key>
-      <value>audio_rate</value>
+      <value>audio_rate/2</value>
     </param>
     <param>
       <key>_enabled</key>