diff --git a/gamutrf/grscan.py b/gamutrf/grscan.py
index cd4b5a10..111040c4 100755
--- a/gamutrf/grscan.py
+++ b/gamutrf/grscan.py
@@ -114,7 +114,7 @@ def __init__(
             tune_step_fft,
             skip_tune_step,
             fft_roll,
-            -100,
+            -200,
             50,
             sample_dir,
             write_samples,