diff --git a/best/wmem/preprocess/be_wdata_preprocessing.m b/best/wmem/preprocess/be_wdata_preprocessing.m
index 0ed3bef..969e3b5 100644
--- a/best/wmem/preprocess/be_wdata_preprocessing.m
+++ b/best/wmem/preprocess/be_wdata_preprocessing.m
@@ -185,15 +185,10 @@
 
                 case 6
                     % Scale one which the noise covariance is calculated
-                    if strcmp(OPTIONS.automatic.Modality(ii).name, 'NIRS')
-                        isc = 3;
-                    else
-                        isc = 2; 
-                    end
+                    isc = OPTIONS.wavelet.selected_scales_covariance;
                     
                     % Select the wavelet coefficient for scale isc
                     % (exclude the 5 first and last boxes) 
-
                     w1 = wavelet_obj.data{1}(:,end/2^(isc)+6:end/2^(isc-1)-5)';
 
                     % The following code might be more robust but needs to
diff --git a/best/wmem/solver/be_wmem_pipelineoptions.m b/best/wmem/solver/be_wmem_pipelineoptions.m
index 1b2299f..3a6e3b9 100644
--- a/best/wmem/solver/be_wmem_pipelineoptions.m
+++ b/best/wmem/solver/be_wmem_pipelineoptions.m
@@ -41,6 +41,11 @@
         DEF.wavelet.nb_levels           = 128;
         DEF.wavelet.shrinkage           = 0;
         DEF.wavelet.selected_scales     = 0;
+        if any(ismember( 'nirs', lower(DataTypes)))
+            DEF.wavelet.selected_scales_covariance     = 3;
+        else
+            DEF.wavelet.selected_scales_covariance     = 2;
+        end
         DEF.wavelet.verbose             = 0;
         DEF.wavelet.single_box          = 0;