diff --git a/owrx/dsp.py b/owrx/dsp.py
index ce45d429..bfb76009 100644
--- a/owrx/dsp.py
+++ b/owrx/dsp.py
@@ -697,10 +697,10 @@ class DspManager(SdrSourceEventClient, ClientDemodulatorSecondaryDspEventClient)
             return RttyDemodulator(50, 85, invert=True)
         elif mod == "sitorb":
             from csdr.chain.digimodes import SitorBDemodulator
-            return SitorBDemodulator()
+            return SitorBDemodulator(100, 170 + 40)
         elif mod == "dsc":
             from csdr.chain.digimodes import DscDemodulator
-            return DscDemodulator()
+            return DscDemodulator(100, 170 + 40)
         elif mod == "cwdecoder":
             from csdr.chain.digimodes import CwDemodulator
             return CwDemodulator(75.0)
diff --git a/owrx/service/__init__.py b/owrx/service/__init__.py
index 929f51d4..a6157b2b 100644
--- a/owrx/service/__init__.py
+++ b/owrx/service/__init__.py
@@ -328,7 +328,7 @@ class ServiceHandler(SdrSourceEventClient):
             return FaxDemodulator(service=True)
         elif mod == "dsc":
             from csdr.chain.digimodes import DscDemodulator
-            return DscDemodulator(service=True)
+            return DscDemodulator(100, 170 + 40, service=True)
         elif mod == "page":
             from csdr.chain.toolbox import PageDemodulator
             return PageDemodulator(service=True)