diff --git a/src/abstractreader.cpp b/src/abstractreader.cpp
--- a/src/abstractreader.cpp
+++ b/src/abstractreader.cpp
@@ -30,13 +30,6 @@ void AbstractReader::pause(bool enabled)
     paused = enabled;
 }
 
-unsigned AbstractReader::numChannels() const
-{
-    // TODO: an alternative is to never set _numChannels to '0'
-    // do not allow '0'
-    return _numChannels == 0 ? 1 : _numChannels;
-}
-
 void AbstractReader::enable(bool enabled)
 {
     if (enabled)
diff --git a/src/abstractreader.h b/src/abstractreader.h
--- a/src/abstractreader.h
+++ b/src/abstractreader.h
@@ -49,8 +49,6 @@ public:
     /// None of the current readers support X channel at the moment
     bool hasX() const final { return false; };
 
-    unsigned numChannels() const;
-
 signals:
     // TODO: should we keep this?
     void numOfChannelsChanged(unsigned);
@@ -67,7 +65,6 @@ public slots:
 protected:
     QIODevice* _device;
     bool paused;
-    unsigned _numChannels;
 
 protected slots:
     /// all derived readers has to override this function
diff --git a/src/asciireader.cpp b/src/asciireader.cpp
--- a/src/asciireader.cpp
+++ b/src/asciireader.cpp
@@ -58,6 +58,13 @@ QWidget* AsciiReader::settingsWidget()
     return &_settingsWidget;
 }
 
+unsigned AsciiReader::numChannels() const
+{
+    // TODO: an alternative is to never set _numChannels to '0'
+    // do not allow '0'
+    return _numChannels == 0 ? 1 : _numChannels;
+}
+
 void AsciiReader::enable(bool enabled)
 {
     if (enabled)
diff --git a/src/asciireader.h b/src/asciireader.h
--- a/src/asciireader.h
+++ b/src/asciireader.h
@@ -32,6 +32,7 @@ class AsciiReader : public AbstractReade
 public:
     explicit AsciiReader(QIODevice* device, QObject *parent = 0);
     QWidget* settingsWidget();
+    unsigned numChannels() const;
     void enable(bool enabled);
     /// Stores settings into a `QSettings`
     void saveSettings(QSettings* settings);
@@ -40,6 +41,7 @@ public:
 
 private:
     AsciiReaderSettings _settingsWidget;
+    unsigned _numChannels;
     /// number of channels will be determined from incoming data
     unsigned autoNumOfChannels;
     QChar delimiter; ///< selected column delimiter
diff --git a/src/binarystreamreader.cpp b/src/binarystreamreader.cpp
--- a/src/binarystreamreader.cpp
+++ b/src/binarystreamreader.cpp
@@ -57,6 +57,11 @@ QWidget* BinaryStreamReader::settingsWid
     return &_settingsWidget;
 }
 
+unsigned BinaryStreamReader::numChannels() const
+{
+    return _numChannels;
+}
+
 void BinaryStreamReader::onNumberFormatChanged(NumberFormat numberFormat)
 {
     switch(numberFormat)
diff --git a/src/binarystreamreader.h b/src/binarystreamreader.h
--- a/src/binarystreamreader.h
+++ b/src/binarystreamreader.h
@@ -36,6 +36,7 @@ class BinaryStreamReader : public Abstra
 public:
     explicit BinaryStreamReader(QIODevice* device, QObject *parent = 0);
     QWidget* settingsWidget();
+    unsigned numChannels() const;
     /// Stores settings into a `QSettings`
     void saveSettings(QSettings* settings);
     /// Loads settings from a `QSettings`.
@@ -43,6 +44,7 @@ public:
 
 private:
     BinaryStreamReaderSettings _settingsWidget;
+    unsigned _numChannels;
     unsigned sampleSize;
     bool skipByteRequested;
     bool skipSampleRequested;
diff --git a/src/demoreader.cpp b/src/demoreader.cpp
--- a/src/demoreader.cpp
+++ b/src/demoreader.cpp
@@ -57,6 +57,11 @@ void DemoReader::enable(bool enabled)
     }
 }
 
+unsigned DemoReader::numChannels() const
+{
+    return _numChannels;
+}
+
 void DemoReader::setNumChannels(unsigned value)
 {
     _settingsWidget.setNumChannels(value);
diff --git a/src/demoreader.h b/src/demoreader.h
--- a/src/demoreader.h
+++ b/src/demoreader.h
@@ -42,6 +42,7 @@ public:
     explicit DemoReader(QIODevice* device, QObject* parent = 0);
 
     QWidget* settingsWidget();
+    unsigned numChannels() const;
     void enable(bool enabled = true);
 
 public slots:
@@ -50,6 +51,7 @@ public slots:
 private:
     DemoReaderSettings _settingsWidget;
 
+    unsigned _numChannels;
     QTimer timer;
     int count;
 
diff --git a/src/framedreader.cpp b/src/framedreader.cpp
--- a/src/framedreader.cpp
+++ b/src/framedreader.cpp
@@ -67,6 +67,11 @@ QWidget* FramedReader::settingsWidget()
     return &_settingsWidget;
 }
 
+unsigned FramedReader::numChannels() const
+{
+    return _numChannels;
+}
+
 void FramedReader::onNumberFormatChanged(NumberFormat numberFormat)
 {
     switch(numberFormat)
diff --git a/src/framedreader.h b/src/framedreader.h
--- a/src/framedreader.h
+++ b/src/framedreader.h
@@ -35,6 +35,7 @@ class FramedReader : public AbstractRead
 public:
     explicit FramedReader(QIODevice* device, QObject *parent = 0);
     QWidget* settingsWidget();
+    unsigned numChannels() const;
     /// Stores settings into a `QSettings`
     void saveSettings(QSettings* settings);
     /// Loads settings from a `QSettings`.
@@ -50,6 +51,7 @@ private:
 
     // settings related members
     FramedReaderSettings _settingsWidget;
+    unsigned _numChannels;
     unsigned sampleSize;
     unsigned settingsInvalid;   /// settings are all valid if this is 0, if not no reading is done
     QByteArray syncWord;