diff --git a/sdrbase/util/db.cpp b/sdrbase/util/db.cpp
index 55c76542d..f76b1b5c7 100644
--- a/sdrbase/util/db.cpp
+++ b/sdrbase/util/db.cpp
@@ -16,17 +16,19 @@
 
 #include "util/db.h"
 #include <cmath>
+#include <cassert>
 
-double CalcDb::dbPower(double magsq, double floordB)
+double CalcDb::dbPower(double magsq, double floor)
 {
-	if (magsq > 0)
+    assert(floor > 0.0);
+
+	if (magsq > floor)
 	{
-	    double val = 10.0 * log10(magsq);
-		return val > floordB ? val : floordB;
+	    return 10.0 * log10(magsq);
 	}
 	else
 	{
-		return floordB;
+		return 10.0 * log10(floor);
 	}
 }
 
diff --git a/sdrbase/util/db.h b/sdrbase/util/db.h
index 05fc7a297..de86e81bb 100644
--- a/sdrbase/util/db.h
+++ b/sdrbase/util/db.h
@@ -22,7 +22,7 @@
 class CalcDb
 {
 public:
-	static double dbPower(double magsq, double floordB = -100.0);
+	static double dbPower(double magsq, double floor = 1e-10);
 	static double powerFromdB(double powerdB);
 };