diff --git a/plugins/samplesource/audioinput/audioinput.cpp b/plugins/samplesource/audioinput/audioinput.cpp
index 8e267e5e1..080a86cb1 100644
--- a/plugins/samplesource/audioinput/audioinput.cpp
+++ b/plugins/samplesource/audioinput/audioinput.cpp
@@ -346,11 +346,9 @@ void AudioInput::applySettings(const AudioInputSettings& settings, QList<QString
 
     if (forwardChange)
     {
-        qint64 dF =
-            ((m_settings.m_iqMapping == AudioInputSettings::IQMapping::L) ||
-            (m_settings.m_iqMapping == AudioInputSettings::IQMapping::R)) ?
-                m_settings.m_sampleRate / 4 : 0;
-        DSPSignalNotification *notif = new DSPSignalNotification(m_settings.m_sampleRate/(1<<m_settings.m_log2Decim), dF);
+        bool realElseComplex = (m_settings.m_iqMapping == AudioInputSettings::L)
+            || (m_settings.m_iqMapping == AudioInputSettings::R);
+        DSPSignalNotification *notif = new DSPSignalNotification(m_settings.m_sampleRate/(1<<m_settings.m_log2Decim), 0, realElseComplex);
         m_sampleRate = notif->getSampleRate();
         m_centerFrequency = notif->getCenterFrequency();
         m_deviceAPI->getDeviceEngineInputMessageQueue()->push(notif);
diff --git a/plugins/samplesource/audioinput/audioinputgui.cpp b/plugins/samplesource/audioinput/audioinputgui.cpp
index e6cd67f54..db0ae7a5f 100644
--- a/plugins/samplesource/audioinput/audioinputgui.cpp
+++ b/plugins/samplesource/audioinput/audioinputgui.cpp
@@ -104,7 +104,18 @@ bool AudioInputGui::deserialize(const QByteArray& data)
 
 bool AudioInputGui::handleMessage(const Message& message)
 {
-    if (AudioInput::MsgConfigureAudioInput::match(message))
+    if (DSPSignalNotification::match(message))
+    {
+        const DSPSignalNotification& notif = (DSPSignalNotification&) message;
+        m_sampleRate = notif.getSampleRate();
+        m_centerFrequency = notif.getCenterFrequency();
+        qDebug("AudioInputGui::handleInputMessages: DSPSignalNotification: SampleRate: %d", notif.getSampleRate());
+        updateSampleRateAndFrequency();
+        updateSpectrum();
+
+        return true;
+    }
+    else if (AudioInput::MsgConfigureAudioInput::match(message))
     {
         const AudioInput::MsgConfigureAudioInput& cfg = (AudioInput::MsgConfigureAudioInput&) message;
 
@@ -117,6 +128,7 @@ bool AudioInputGui::handleMessage(const Message& message)
         blockApplySettings(true);
         displaySettings();
         blockApplySettings(false);
+
         return true;
     }
     else if (AudioInput::MsgStartStop::match(message))
@@ -142,23 +154,9 @@ void AudioInputGui::handleInputMessages()
     {
         qDebug("AudioInputGui::handleInputMessages: message: %s", message->getIdentifier());
 
-        if (DSPSignalNotification::match(*message))
-        {
-            DSPSignalNotification* notif = (DSPSignalNotification*) message;
-            m_sampleRate = notif->getSampleRate();
-            m_centerFrequency = notif->getCenterFrequency();
-            qDebug("AudioInputGui::handleInputMessages: DSPSignalNotification: SampleRate: %d", notif->getSampleRate());
-            updateSampleRateAndFrequency();
-
+        if (handleMessage(*message)) {
             delete message;
         }
-        else
-        {
-            if (handleMessage(*message))
-            {
-                delete message;
-            }
-        }
     }
 }
 
@@ -246,6 +244,7 @@ void AudioInputGui::displaySettings()
 	ui->iqImbalance->setChecked(m_settings.m_iqImbalance);
     refreshSampleRates(ui->device->currentText());
     displayFcTooltip();
+    updateSpectrum();
 }
 
 void AudioInputGui::displayFcTooltip()
@@ -259,6 +258,15 @@ void AudioInputGui::displayFcTooltip()
     ui->fcPos->setToolTip(tr("Relative position of device center frequency: %1 kHz").arg(QString::number(fShift / 1000.0f, 'g', 5)));
 }
 
+void AudioInputGui::updateSpectrum()
+{
+    bool realElseComplex = (m_settings.m_iqMapping == AudioInputSettings::L)
+        || (m_settings.m_iqMapping == AudioInputSettings::R);
+    m_deviceUISet->getSpectrum()->setCenterFrequency(0);
+    m_deviceUISet->getSpectrum()->setSampleRate(m_sampleRate);
+    m_deviceUISet->getSpectrum()->setSsbSpectrum(realElseComplex);
+}
+
 void AudioInputGui::on_device_currentIndexChanged(int index)
 {
     (void) index;
diff --git a/plugins/samplesource/audioinput/audioinputgui.h b/plugins/samplesource/audioinput/audioinputgui.h
index 61767a67c..277bb1572 100644
--- a/plugins/samplesource/audioinput/audioinputgui.h
+++ b/plugins/samplesource/audioinput/audioinputgui.h
@@ -66,6 +66,7 @@ private:
     void refreshSampleRates(QString deviceName);
     void displaySettings();
     void displayFcTooltip();
+    void updateSpectrum();
     void sendSettings();
     void updateSampleRateAndFrequency();
     bool handleMessage(const Message& message);
diff --git a/plugins/samplesource/audioinput/audioinputgui.ui b/plugins/samplesource/audioinput/audioinputgui.ui
index b79790416..a34518db5 100644
--- a/plugins/samplesource/audioinput/audioinputgui.ui
+++ b/plugins/samplesource/audioinput/audioinputgui.ui
@@ -386,6 +386,9 @@
        <property name="maximum">
         <number>10</number>
        </property>
+       <property name="pageStep">
+        <number>1</number>
+       </property>
        <property name="value">
         <number>10</number>
        </property>
diff --git a/plugins/samplesource/audioinput/audioinputworker.cpp b/plugins/samplesource/audioinput/audioinputworker.cpp
index a70967cd1..1e2e647b0 100644
--- a/plugins/samplesource/audioinput/audioinputworker.cpp
+++ b/plugins/samplesource/audioinput/audioinputworker.cpp
@@ -33,8 +33,7 @@ AudioInputWorker::AudioInputWorker(SampleSinkFifo* sampleFifo, AudioFifo *fifo,
     m_log2Decim(0),
     m_iqMapping(AudioInputSettings::IQMapping::L),
     m_convertBuffer(m_convBufSamples),
-    m_sampleFifo(sampleFifo),
-    m_quNCOPhase(0)
+    m_sampleFifo(sampleFifo)
 {
 }
 
@@ -62,31 +61,10 @@ void AudioInputWorker::workIQ(unsigned int nbRead)
     {
         for (uint32_t i = 0; i < nbRead; i++)
         {
-            qint16 r = m_buf[i*2 + (m_iqMapping == AudioInputSettings::IQMapping::R ? 1 : 0)]; // real sample
-
-            if (m_quNCOPhase == 0) // 0
-            {
-                m_buf[i*2]   = r;  // 1
-                m_buf[i*2+1] = 0;  // 0
-                m_quNCOPhase = 1;  // next phase
-            }
-            else if (m_quNCOPhase == 1) // -pi/2
-            {
-                m_buf[i*2]   = 0;  // 0
-                m_buf[i*2+1] = -r; // -1
-                m_quNCOPhase = 2;  // next phase
-            }
-            else if (m_quNCOPhase == 2) // pi or -pi
-            {
-                m_buf[i*2]   = -r; // -1
-                m_buf[i*2+1] = 0;  // 0
-                m_quNCOPhase = 3;  // next phase
-            }
-            else if (m_quNCOPhase == 3) // pi/2
-            {
-                m_buf[i*2]   = 0;  // 0
-                m_buf[i*2+1] = r;  // 1
-                m_quNCOPhase = 0;  // next phase
+            if (m_iqMapping == AudioInputSettings::IQMapping::L) {
+                m_buf[i*2+1] = m_buf[i*2];
+            } else {
+                m_buf[i*2] = m_buf[i*2+1];
             }
         }
     }
diff --git a/plugins/samplesource/audioinput/audioinputworker.h b/plugins/samplesource/audioinput/audioinputworker.h
index ad7bfeb64..7624994cf 100644
--- a/plugins/samplesource/audioinput/audioinputworker.h
+++ b/plugins/samplesource/audioinput/audioinputworker.h
@@ -53,7 +53,6 @@ private:
     SampleVector m_convertBuffer;
     SampleSinkFifo* m_sampleFifo;
     Decimators<qint32, qint16, SDR_RX_SAMP_SZ, 16, true> m_decimatorsIQ;
-    int m_quNCOPhase; //!< Quarter sample rate pseudo NCO phase index (0, 90, 180, 270)
 
     void workIQ(unsigned int nbRead);
     void decimate(qint16 *buf, unsigned int nbRead);