diff --git a/PA_Calculator.icns b/PA_Calculator.icns
new file mode 100644
index 0000000..dd555a3
Binary files /dev/null and b/PA_Calculator.icns differ
diff --git a/PA_Calculator.pro b/PA_Calculator.pro
index d28fff8..b78227d 100644
--- a/PA_Calculator.pro
+++ b/PA_Calculator.pro
@@ -3,7 +3,7 @@ QT       += core gui
 greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
 
 CONFIG += c++11
-
+CONFIG+=sdk_no_version_check
 # You can make your code fail to compile if it uses deprecated APIs.
 # In order to do so, uncomment the following line.
 #DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0
@@ -29,9 +29,16 @@ FORMS += \
     library.ui \
     mainwindow.ui
 
-CONFIG += lrelease
-CONFIG += embed_translations
+TARGET = "PA Calculator"
 
+
+macx {
+    ICON = PA_Calculator.icns
+}
+
+win32 {
+    RC_ICONS = PA_Calculator.ico
+}
 # Default rules for deployment.
 qnx: target.path = /tmp/$${TARGET}/bin
 else: unix:!android: target.path = /opt/$${TARGET}/bin
diff --git a/library.ui b/library.ui
index 6c09857..22677ff 100644
--- a/library.ui
+++ b/library.ui
@@ -11,7 +11,7 @@
    </rect>
   </property>
   <property name="windowTitle">
-   <string>Dialog</string>
+   <string>Library Editor</string>
   </property>
   <layout class="QGridLayout" name="gridLayout">
    <item row="1" column="0">
@@ -27,7 +27,7 @@
    <item row="0" column="0">
     <widget class="QTabWidget" name="tabWidget">
      <property name="currentIndex">
-      <number>2</number>
+      <number>0</number>
      </property>
      <widget class="QWidget" name="amps">
       <attribute name="title">
diff --git a/main.cpp b/main.cpp
index 950db3a..fd3e533 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,14 +1,10 @@
 #include "mainwindow.h"
 
 #include <QApplication>
-#include <QLocale>
-#include <QTranslator>
 
 int main(int argc, char *argv[])
 {
     QApplication a(argc, argv);
-
-
     MainWindow w;
     w.show();
     return a.exec();
diff --git a/mainwindow.cpp b/mainwindow.cpp
index f582d88..f98a754 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -54,8 +54,20 @@ void MainWindow::on_ComboBox_selectSensUnit_currentIndexChanged(int index)
 
 void MainWindow::on_pushButton_requestLimiter_clicked()
 {
-    qreal vMaxSpeakerInRMS=20*std::log10(qSqrt(ui->spinBox_speakerImp->value()*ui->spinBox_speakerRMSPower->value())/0.7746);
-    qreal vMaxSpeakerInPeak=20*std::log10(qSqrt(ui->spinBox_speakerImp->value()*ui->spinBox_speakerPeakPower->value())/0.7746);
+    qreal speakerCount=ui->spinBox_speakerCount->value();
+    qreal speakerImp=ui->spinBox_speakerImp->value()/speakerCount;
+    qreal speakerRMS=ui->spinBox_speakerRMSPower->value()*speakerCount;
+    qreal speakerPeak=ui->spinBox_speakerPeakPower->value()*speakerCount;
+    qreal ampImp=ui->spinBox_AmpImp->value();
+
+    if (speakerImp!=ampImp){
+        QMessageBox msgBox(QMessageBox::Critical,"Impedance Mismatch",QString("The speaker impedance (")+QString::number(speakerImp)+QString(" Ohm) doesn't match with the amplifier impedance (")+QString::number(ampImp)+QString(" Ohm). Maybe you can change the amplifier mode?"));
+        msgBox.exec();
+        return;
+    }
+
+    qreal vMaxSpeakerInRMS=20*std::log10(qSqrt(speakerImp*speakerRMS)/0.7746);
+    qreal vMaxSpeakerInPeak=20*std::log10(qSqrt(speakerImp*speakerPeak)/0.7746);
 
     qreal vAmpSens_volt=0;
     qreal vAmpsens_dBu=0;
@@ -77,20 +89,23 @@ void MainWindow::on_pushButton_requestLimiter_clicked()
     qreal releaseTimeRMS=attackTimeRMS*8;
     qreal releaseTimePeak=attackTimeRMS;
 
+
+
+
     if (vAmpsens_dBu<vMaxAmpInRMS){
         QMessageBox msgBox(QMessageBox::Warning,"Amplifier can't deliver maximum RMS power","The maximum power level of the amplifier is below the maximum RMS power level of the speaker. To protect the speaker from a distorted signal the amplifier might deliver, a peak limiter is required with the amplifiers input sensitivty set as its threshold.");
         msgBox.exec();
         ui->label_thresholdRMS->setText(QString("not required"));
         ui->label_attackTimeRMS->setText(QString::number(attackTimeRMS,'f',2)+QString(" ms"));
         ui->label_releaseTimeRMS->setText(QString::number(releaseTimeRMS,'f',2)+QString(" ms"));
-        ui->label_UMaxSpeakerInRMS->setText(QString::number(vMaxSpeakerInRMS,'f',2)+QString(" dBU (")+QString::number(qSqrt(ui->spinBox_speakerImp->value()*ui->spinBox_speakerRMSPower->value()),'f',2)+QString(" V)"));
+        ui->label_UMaxSpeakerInRMS->setText(QString::number(vMaxSpeakerInRMS,'f',2)+QString(" dBU (")+QString::number(qSqrt(speakerImp*speakerRMS),'f',2)+QString(" V)"));
         ui->label_UMaxAmpInRMS->setText(QString("not applicable"));
 
 
         thresholdPeak=-18-(ui->spinBox_digitalNominalLevel->value()-vAmpsens_dBu);
         ui->label_thresholdPeak->setText(QString::number(thresholdPeak,'f',1)+QString(" dBFS"));
         ui->label_releaseTimePeak->setText(QString::number(releaseTimePeak,'f',2)+QString(" ms"));
-        ui->label_UMaxSpeakerInPeak->setText(QString::number(vMaxSpeakerInPeak,'f',2)+QString(" dBU (")+QString::number(qSqrt(ui->spinBox_speakerImp->value()*ui->spinBox_speakerPeakPower->value()),'f',2)+QString(" V)"));
+        ui->label_UMaxSpeakerInPeak->setText(QString::number(vMaxSpeakerInPeak,'f',2)+QString(" dBU (")+QString::number(qSqrt(speakerImp*speakerPeak),'f',2)+QString(" V)"));
         ui->label_UMaxAmpInPeak->setText(QString::number(vAmpSens_volt,'f',2)+QString(" V (= input sensitivity)"));
     }else if (vAmpsens_dBu<vMaxAmpInPeak){
         QMessageBox msgBox(QMessageBox::Warning,"Amplifier can't deliver maximum peak power","The maximum power level of the amplifier is below the maximum peak power level of the speaker. To protect the speaker from a distorted signal the amplifier might deliver, a peak limiter is required with the amplifiers input sensitivty set as its threshold.");
@@ -99,24 +114,24 @@ void MainWindow::on_pushButton_requestLimiter_clicked()
         ui->label_thresholdRMS->setText(QString::number(thresholdRMS,'f',1)+QString(" dBFS"));
         ui->label_attackTimeRMS->setText(QString::number(attackTimeRMS,'f',2)+QString(" ms"));
         ui->label_releaseTimeRMS->setText(QString::number(releaseTimeRMS,'f',2)+QString(" ms"));
-        ui->label_UMaxSpeakerInRMS->setText(QString::number(vMaxSpeakerInRMS,'f',2)+QString(" dBU (")+QString::number(qSqrt(ui->spinBox_speakerImp->value()*ui->spinBox_speakerRMSPower->value()),'f',2)+QString(" V)"));
+        ui->label_UMaxSpeakerInRMS->setText(QString::number(vMaxSpeakerInRMS,'f',2)+QString(" dBU (")+QString::number(qSqrt(speakerImp*speakerRMS),'f',2)+QString(" V)"));
         ui->label_UMaxAmpInRMS->setText(QString::number(vMaxAmpInRMS,'f',2)+QString(" dBU (")+QString::number(qPow(10,vMaxAmpInRMS/20)*0.7746,'f',2)+QString(" V)"));
 
         thresholdPeak=-18-(ui->spinBox_digitalNominalLevel->value()-vAmpsens_dBu);
         ui->label_thresholdPeak->setText(QString::number(thresholdPeak,'f',1)+QString(" dBFS"));
         ui->label_releaseTimePeak->setText(QString::number(releaseTimePeak,'f',2)+QString(" ms"));
-        ui->label_UMaxSpeakerInPeak->setText(QString::number(vMaxSpeakerInPeak,'f',2)+QString(" dBU (")+QString::number(qSqrt(ui->spinBox_speakerImp->value()*ui->spinBox_speakerPeakPower->value()),'f',2)+QString(" V)"));
+        ui->label_UMaxSpeakerInPeak->setText(QString::number(vMaxSpeakerInPeak,'f',2)+QString(" dBU (")+QString::number(qSqrt(speakerImp*speakerPeak),'f',2)+QString(" V)"));
         ui->label_UMaxAmpInPeak->setText(QString::number(vAmpSens_volt,'f',2)+QString(" V (= input sensitivity)"));
     }else{
         ui->label_thresholdRMS->setText(QString::number(thresholdRMS,'f',1)+QString(" dBFS"));
         ui->label_attackTimeRMS->setText(QString::number(attackTimeRMS,'f',2)+QString(" ms"));
         ui->label_releaseTimeRMS->setText(QString::number(releaseTimeRMS,'f',2)+QString(" ms"));
-        ui->label_UMaxSpeakerInRMS->setText(QString::number(vMaxSpeakerInRMS,'f',2)+QString(" dBU (")+QString::number(qSqrt(ui->spinBox_speakerImp->value()*ui->spinBox_speakerRMSPower->value()),'f',2)+QString(" V)"));
+        ui->label_UMaxSpeakerInRMS->setText(QString::number(vMaxSpeakerInRMS,'f',2)+QString(" dBU (")+QString::number(qSqrt(speakerImp*speakerRMS),'f',2)+QString(" V)"));
         ui->label_UMaxAmpInRMS->setText(QString::number(vMaxAmpInRMS,'f',2)+QString(" dBU (")+QString::number(qPow(10,vMaxAmpInRMS/20)*0.7746,'f',2)+QString(" V)"));
 
         ui->label_thresholdPeak->setText(QString::number(thresholdPeak,'f',1)+QString(" dBFS"));
         ui->label_releaseTimePeak->setText(QString::number(releaseTimePeak,'f',2)+QString(" ms"));
-        ui->label_UMaxSpeakerInPeak->setText(QString::number(vMaxSpeakerInPeak,'f',2)+QString(" dBU (")+QString::number(qSqrt(ui->spinBox_speakerImp->value()*ui->spinBox_speakerPeakPower->value()),'f',2)+QString(" V)"));
+        ui->label_UMaxSpeakerInPeak->setText(QString::number(vMaxSpeakerInPeak,'f',2)+QString(" dBU (")+QString::number(qSqrt(speakerImp*speakerPeak),'f',2)+QString(" V)"));
         ui->label_UMaxAmpInPeak->setText(QString::number(vMaxAmpInPeak,'f',2)+QString(" dBU (")+QString::number(qPow(10,vMaxAmpInPeak/20)*0.7746,'f',2)+QString(" V)"));
     }
 
diff --git a/mainwindow.ui b/mainwindow.ui
index 8ba9788..4cc5dff 100644
--- a/mainwindow.ui
+++ b/mainwindow.ui
@@ -6,13 +6,16 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>1230</width>
+    <width>1141</width>
     <height>611</height>
    </rect>
   </property>
   <property name="windowTitle">
    <string>PA Calculator</string>
   </property>
+  <property name="locale">
+   <locale language="English" country="Germany"/>
+  </property>
   <widget class="QWidget" name="centralwidget">
    <layout class="QVBoxLayout" name="verticalLayout">
     <item>
@@ -289,17 +292,17 @@
              </property>
             </widget>
            </item>
-           <item row="5" column="0">
+           <item row="7" column="0">
             <widget class="QLabel" name="label_21">
              <property name="text">
               <string>Load Speaker from library</string>
              </property>
             </widget>
            </item>
-           <item row="5" column="1">
+           <item row="7" column="1">
             <widget class="QComboBox" name="comboBox_librarySpeaker"/>
            </item>
-           <item row="4" column="1">
+           <item row="6" column="1">
             <spacer name="verticalSpacer_4">
              <property name="orientation">
               <enum>Qt::Vertical</enum>
@@ -312,7 +315,7 @@
              </property>
             </spacer>
            </item>
-           <item row="6" column="1">
+           <item row="8" column="1">
             <widget class="QPushButton" name="pushButton_loadSpeaker">
              <property name="minimumSize">
               <size>
@@ -325,6 +328,36 @@
              </property>
             </widget>
            </item>
+           <item row="5" column="1">
+            <widget class="QSpinBox" name="spinBox_speakerCount">
+             <property name="minimum">
+              <number>1</number>
+             </property>
+             <property name="maximum">
+              <number>2</number>
+             </property>
+            </widget>
+           </item>
+           <item row="4" column="1">
+            <spacer name="verticalSpacer_6">
+             <property name="orientation">
+              <enum>Qt::Vertical</enum>
+             </property>
+             <property name="sizeHint" stdset="0">
+              <size>
+               <width>20</width>
+               <height>40</height>
+              </size>
+             </property>
+            </spacer>
+           </item>
+           <item row="5" column="0">
+            <widget class="QLabel" name="label_24">
+             <property name="text">
+              <string>Number of speaker in parallel</string>
+             </property>
+            </widget>
+           </item>
           </layout>
          </item>
         </layout>
@@ -672,7 +705,7 @@
     <rect>
      <x>0</x>
      <y>0</y>
-     <width>1230</width>
+     <width>1141</width>
      <height>24</height>
     </rect>
    </property>
@@ -686,7 +719,6 @@
    </widget>
    <addaction name="menuLibrary"/>
   </widget>
-  <widget class="QStatusBar" name="statusbar"/>
   <action name="actionEditLibrary">
    <property name="text">
     <string>Edit Library</string>
diff --git a/resources.qrc b/resources.qrc
new file mode 100644
index 0000000..beb1991
--- /dev/null
+++ b/resources.qrc
@@ -0,0 +1,5 @@
+<RCC>
+    <qresource prefix="/Icons">
+        <file>PA_Calculator.icns</file>
+    </qresource>
+</RCC>