diff --git a/spimple/apps/spi_fitter.py b/spimple/apps/spi_fitter.py
index 35d0d07..b9a054d 100755
--- a/spimple/apps/spi_fitter.py
+++ b/spimple/apps/spi_fitter.py
@@ -72,7 +72,7 @@ def spi_fitter():
                         "Will overwrite in fits headers of output.")
     parser.add_argument('-otype', '--out_dtype', default='f4', type=str,
                         help="Data type of output. Default is single precision")
-    parser.add_argument('-acr', '--add-convolved-residuals', type=str2bool, nargs='?', const=True, default=True,
+    parser.add_argument('-acr', '--add-convolved-residuals', type=str2bool, nargs='?', const=True, default=False,
                         help='Flag to add in the convolved residuals before fitting components')
     parser.add_argument('-ms', "--ms", nargs="+", type=str,
                         help="Mesurement sets used to make the image. \n"
@@ -95,6 +95,10 @@ def spi_fitter():
                         help="Correlation typ i.e. linear or circular. ")
     parser.add_argument('-band', "--band", type=str, default='l',
                         help="Band to use with JimBeam. L or UHF")
+    parser.add_argument('-db', '--deselect-bands', default=None, nargs='+', type=int,
+                        help="Indices of subbands to exclude from the fitting \n"
+                        "By default, all the sub-bands are used for the residual image. \n"
+                        "e.g. -db 1 2 will exclude sub-bands indexed at 1 & 2.")
 
     opts = parser.parse_args()
     opts = OmegaConf.create(vars(opts))
@@ -160,10 +164,10 @@ def spi_fitter():
     m_coord, ref_m = data_from_header(mhdr, axis=2)
     m_coord -= ref_m
 
-    if mhdr["CTYPE4"].lower() == 'freq':
+    if mhdr["CTYPE4"].lower() in ['freq', 'speclnmf']:
         freq_axis = 4
         stokes_axis = 3
-    elif mhdr["CTYPE3"].lower() == 'freq':
+    elif mhdr["CTYPE3"].lower() in ['freq', 'speclnmf']:
         freq_axis = 3
         stokes_axis = 4
     else:
@@ -354,11 +358,32 @@ def spi_fitter():
     else:
         print("No residual provided. Setting  threshold i.t.o dynamic range. "
               f"Max dynamic range is {opts.maxDR}", file=log)
-        threshold = model.max()/opts.maxDR
+        mask = ~np.isnan(model)
+        threshold = model[mask].max()/opts.maxDR
         rms_cube = None
 
     print(f"Threshold set to {threshold} Jy.", file=log)
 
+    # remove completely nan slices
+    freq_mask = np.isnan(model)
+    fidx = ~np.all(freq_mask, axis=(1,2))
+
+    # exclude any bands that might be awful
+    if opts.deselect_bands:
+        print(f"Deselected bands are: {opts.deselect_bands}", file=log)
+        for bidx in opts.deselect_bands:
+            fidx[bidx] = False
+
+    if fidx.any():
+        model = model[fidx]
+        beam_image = beam_image[fidx]
+        freqs = freqs[fidx]
+        gaussparf = list(gaussparf)
+        #for i, par in enumerate(gaussparf):
+        #    if not fidx[i]:
+        #        gaussparf.remove(par)
+        new_hdr = set_header_info(mhdr, ref_freq, freq_axis, opts, tuple(gaussparf))
+
     # get pixels above threshold
     minimage = np.amin(model, axis=0)
     maskindices = np.argwhere(minimage > threshold)
@@ -372,7 +397,7 @@ def spi_fitter():
 
     # set weights for fit
     if opts.channel_weights is not None:
-        weights = np.array(opts.channel_weights)
+        weights = np.array(opts.channel_weights)[fidx]
         try:
             assert weights.size == nband
             print("Using provided channel weights.", file=log)
@@ -380,21 +405,23 @@ def spi_fitter():
             print("Number of provided channel weights not equal "
                   "to number of imaging bands", file=log)
     else:
-        if len(opts.residual) > 1:
+        if opts.residual:
             print("Getting weights from list of image headers.", file=log)
-            rhdr = [fits.getheader(res) for res in opts.residual]
+            rhdr = []
+            for i, res in enumerate(opts.residual):
+                rhdr.append(fits.getheader(res))
             weights = np.array([hdr["WSCVWSUM"] for hdr in rhdr])
             weights /= weights.max()
         elif rms_cube is not None:
             print("Using RMS in each imaging band to determine weights.",
                   file=log)
-            weights = np.where(rms_cube > 0, 1.0/rms_cube**2, 0.0)
+            weights = np.where(rms_cube[fidx] > 0, 1.0/rms_cube[fidx]**2, 0.0)
             # normalise
             weights /= weights.max()
         else:
             print("No residual or channel weights provided. "
                   "Using equal weights.", file=log)
-            weights = np.ones(nband, dtype=np.float64)
+            weights = np.ones(fidx.sum(), dtype=np.float64)
         print(f"Channel weights: {weights}", file=log)
 
     ncomps, _ = fitcube.shape