diff --git a/spectrogramplot.cpp b/spectrogramplot.cpp
index 7bee274..03afcc1 100644
--- a/spectrogramplot.cpp
+++ b/spectrogramplot.cpp
@@ -60,7 +60,8 @@ SpectrogramPlot::SpectrogramPlot(std::shared_ptr<SampleSource<std::complex<float
 
 void SpectrogramPlot::paintFront(QPainter &painter, QRect &rect, range_t<off_t> sampleRange)
 {
-    tuner.paintFront(painter, rect, sampleRange);
+    if (tunerEnabled())
+        tuner.paintFront(painter, rect, sampleRange);
 }
 
 void SpectrogramPlot::paintMid(QPainter &painter, QRect &rect, range_t<off_t> sampleRange)
@@ -175,7 +176,10 @@ int SpectrogramPlot::linesPerTile()
 
 bool SpectrogramPlot::mouseEvent(QEvent::Type type, QMouseEvent event)
 {
-    return tuner.mouseEvent(type, event);
+    if (tunerEnabled())
+        return tuner.mouseEvent(type, event);
+
+    return false;
 }
 
 std::shared_ptr<AbstractSampleSource> SpectrogramPlot::output()
@@ -213,6 +217,11 @@ void SpectrogramPlot::setZoomLevel(int zoom)
     zoomLevel = zoom;
 }
 
+bool SpectrogramPlot::tunerEnabled()
+{
+    return (tunerOutput->subscriberCount() > 0);
+}
+
 void SpectrogramPlot::tunerMoved()
 {
     tunerFilter->set_center_freq(getTunerCentre());
diff --git a/spectrogramplot.h b/spectrogramplot.h
index f474171..7cdf2a2 100644
--- a/spectrogramplot.h
+++ b/spectrogramplot.h
@@ -80,6 +80,7 @@ private:
     float getTunerCentre();
     std::vector<float> getTunerTaps();
     int linesPerTile();
+    bool tunerEnabled();
 };
 
 class TileCacheKey