diff --git a/bbfm_inference.sh b/bbfm_inference.sh
new file mode 100755
index 0000000..04bd3ae
--- /dev/null
+++ b/bbfm_inference.sh
@@ -0,0 +1,47 @@
+#!/bin/bash -x
+#
+# Some automation around inference_bbfm.py to help with testing
+
+OPUS=build/src
+PATH=${PATH}:${OPUS}
+
+if [ $# -lt 3 ]; then
+    echo "usage (write output to file):"
+    echo "  ./bbfm_inference.sh model in.s16 out.wav [optional bbfm_inference.py args]"
+    echo "usage (play output with aplay):"
+    echo "  ./bbfm_inference.sh model in.s16 - [optional bbfm_inference.py args]"
+    exit 1
+fi
+
+if [ ! -f $1 ]; then
+    echo "can't find $1"
+    exit 1
+fi
+if [ ! -f $2 ]; then
+    echo "can't find $2"
+    exit 1
+fi
+
+model=$1
+input_speech=$2
+output_speech=$3
+features_in=features_in.f32
+features_out=features_out.f32
+
+# eat first 3 args before passing rest to inference.py in $@
+shift; shift; shift
+
+lpcnet_demo -features ${input_speech} ${features_in}
+python3 ./bbfm_inference.py ${model} ${features_in} ${features_out} "$@"
+if [ $? -ne 0 ]; then
+  exit 1
+fi
+if [ $output_speech == "-" ]; then
+    tmp=$(mktemp)
+    lpcnet_demo -fargan-synthesis ${features_out} ${tmp}
+    aplay $tmp -r 16000 -f S16_LE 2>/dev/null
+elif [ $output_speech != "/dev/null" ]; then
+    tmp=$(mktemp)
+    lpcnet_demo -fargan-synthesis ${features_out} ${tmp}
+    sox -t .s16 -r 16000 -c 1 ${tmp} ${output_speech}
+fi
diff --git a/multipath_samples.m b/multipath_samples.m
index f589f2b..208f711 100644
--- a/multipath_samples.m
+++ b/multipath_samples.m
@@ -41,6 +41,7 @@ function multipath_samples(ch, Fs, Rs, Nc, Nseconds, H_fn, G_fn="")
     if Nc > 1 
       mesh(H(1:10*Rs,:))
     else
+      # single carrier case
       Nsecplot=1
       subplot(211); plot(H(1:Nsecplot*Rs,:)); xlabel('Symbols'); ylabel('|H|')
       subplot(212); plot(20*log10(H(1:Nsecplot*Rs,:))); xlabel('Symbols'); ylabel('|H| (dB)')
@@ -58,8 +59,8 @@ function multipath_samples(ch, Fs, Rs, Nc, Nseconds, H_fn, G_fn="")
         end
       end
       LCR_meas = LC/Nseconds
+      subplot(211); hold on; stem(LC_log,sqrt(P)*ones(length(LC_log))); hold off; axis([0 Nsecplot*Rs 0 3]);
     end
-    subplot(211); hold on; stem(LC_log,sqrt(P)*ones(length(LC_log))); hold off; axis([0 Nsecplot*Rs 0 3]);
     printf("H file size is Nseconds*Rs*Nc*(4 bytes/sample) = %d*%d*%d*4 = %d bytes\n", Nseconds,Rs,Nc,Nseconds*Rs*Nc*4)
     f=fopen(H_fn,"wb");
     [r c] = size(H);