diff --git a/inputsource.cpp b/inputsource.cpp
index de1bbc5..664f8cc 100644
--- a/inputsource.cpp
+++ b/inputsource.cpp
@@ -75,6 +75,17 @@ void InputSource::openFile(const char *filename)
     invalidate();
 }
 
+void InputSource::setSampleRate(off_t rate)
+{
+    sampleRate = rate;
+    invalidate();
+}
+
+off_t InputSource::rate()
+{
+    return sampleRate;
+}
+
 std::unique_ptr<std::complex<float>[]> InputSource::getSamples(off_t start, off_t length)
 {
     if (inputFile == nullptr)
diff --git a/inputsource.h b/inputsource.h
index 75feeac..e991cef 100644
--- a/inputsource.h
+++ b/inputsource.h
@@ -28,6 +28,7 @@ private:
     FILE *inputFile = nullptr;
     off_t fileSize = 0;
     off_t sampleCount = 0;
+    off_t sampleRate = 0;
     std::complex<float> *mmapData = nullptr;
 
 public:
@@ -39,4 +40,6 @@ public:
     off_t count() {
         return sampleCount;
     };
+    void setSampleRate(off_t rate);
+    off_t rate();
 };
diff --git a/mainwindow.cpp b/mainwindow.cpp
index ef079eb..d66d449 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -37,6 +37,7 @@ MainWindow::MainWindow()
     setCentralWidget(plots);
 
     connect(dock, SIGNAL(openFile(QString)), this, SLOT(openFile(QString)));
+    connect(dock->sampleRate, SIGNAL(textChanged(QString)), this, SLOT(setSampleRate(QString)));
     connect(dock, SIGNAL(fftSizeChanged(int)), plots, SLOT(setFFTSize(int)));
     connect(dock->zoomLevelSlider, SIGNAL(valueChanged(int)), plots, SLOT(setZoomLevel(int)));
     connect(dock->powerMaxSlider, SIGNAL(valueChanged(int)), plots, SLOT(setPowerMax(int)));
@@ -53,3 +54,8 @@ void MainWindow::openFile(QString fileName)
     this->setWindowTitle(title.arg(QApplication::applicationName(),fileName.section('/',-1,-1)));
     input->openFile(fileName.toUtf8().constData());
 }
+
+void MainWindow::setSampleRate(QString rate)
+{
+    input->setSampleRate(rate.toInt());
+}
diff --git a/mainwindow.h b/mainwindow.h
index f29bd99..2a3429c 100644
--- a/mainwindow.h
+++ b/mainwindow.h
@@ -34,6 +34,7 @@ public:
 
 public slots:
     void openFile(QString fileName);
+    void setSampleRate(QString rate);
 
 private:
     SpectrogramControls *dock;
diff --git a/samplebuffer.h b/samplebuffer.h
index 4574931..b7a5140 100644
--- a/samplebuffer.h
+++ b/samplebuffer.h
@@ -38,4 +38,7 @@ public:
     virtual off_t count() {
         return src->count();
     };
+    off_t rate() {
+        return src->rate();
+    };
 };
diff --git a/samplesource.h b/samplesource.h
index 7035218..e69ab8c 100644
--- a/samplesource.h
+++ b/samplesource.h
@@ -35,6 +35,7 @@ public:
     virtual std::unique_ptr<T[]> getSamples(off_t start, off_t length) = 0;
     virtual void invalidateEvent() { };
     virtual off_t count() = 0;
+    virtual off_t rate() = 0;
     void subscribe(Subscriber *subscriber);
     void unsubscribe(Subscriber *subscriber);
 
diff --git a/spectrogramcontrols.cpp b/spectrogramcontrols.cpp
index 80935b9..17fbee9 100644
--- a/spectrogramcontrols.cpp
+++ b/spectrogramcontrols.cpp
@@ -32,7 +32,7 @@ SpectrogramControls::SpectrogramControls(const QString & title, QWidget * parent
     fileOpenButton = new QPushButton("Open file...", widget);
     layout->addRow(fileOpenButton);
 
-    sampleRate = new QLineEdit("8000000");
+    sampleRate = new QLineEdit();
     sampleRate->setValidator(new QIntValidator(this));
     layout->addRow(new QLabel(tr("Sample rate:")), sampleRate);
 
@@ -91,6 +91,7 @@ SpectrogramControls::SpectrogramControls(const QString & title, QWidget * parent
 
 void SpectrogramControls::setDefaults()
 {
+    sampleRate->setText("8000000");
     fftSizeSlider->setValue(9);
     zoomLevelSlider->setValue(0);
     powerMaxSlider->setValue(0);