diff --git a/csdr.py b/csdr.py
index 249605f..673146c 100644
--- a/csdr.py
+++ b/csdr.py
@@ -150,7 +150,7 @@ class dsp(object):
         if which == "nfm":
             chain += ["csdr fmdemod_quadri_cf", "csdr limit_ff"]
             chain += last_decimation_block
-            chain += ["csdr deemphasis_nfm_ff {output_rate}"]
+            chain += ["csdr deemphasis_nfm_ff {audio_rate}"]
             if self.get_audio_rate() != self.get_output_rate():
                 chain += [
                     "sox -t raw -r {audio_rate} -e floating-point -b 32 -c 1 --buffer 32 - -t raw -r {output_rate} -e signed-integer -b 16 -c 1 - "
@@ -433,7 +433,7 @@ class dsp(object):
 
     def isPacket(self, demodulator = None):
         if demodulator is None:
-            demodulator = self.get_demodulator()
+            demodulator = self.get_secondary_demodulator()
         return demodulator == "packet"
 
     def set_output_rate(self, output_rate):