diff --git a/get_time_freq_detection.py b/get_time_freq_detection.py
index bacfc0b1f9a3ab0861a69a0380df634a599044a0..5db9aa43c0cbb8a356d50800f7b410c1eba189d8 100644
--- a/get_time_freq_detection.py
+++ b/get_time_freq_detection.py
@@ -45,7 +45,7 @@ for j in range (len(df)):
 	df.loc[j,('annot')] = names[int(df.espece.iloc[j])]
 
 print('Calculating the positions','\n')
-df['midl'] = (df.x*8)+(df.idx.astype(int))
+df['midl'] = (df.x*DUREE_SPECTRO)+(df.idx.astype(int))
 df['freq_center'] = (1-df.y)*(SR/2)
 df['freq_min'] = df.freq_center - (df.h*(SR/2))/2
 df['freq_max'] = df.freq_center + (df.h*(SR/2))/2