diff --git a/src/panel/SpectrumPanel.cpp b/src/panel/SpectrumPanel.cpp
index c615490..2b6f65e 100644
--- a/src/panel/SpectrumPanel.cpp
+++ b/src/panel/SpectrumPanel.cpp
@@ -132,27 +132,31 @@ void SpectrumPanel::drawPanelContents() {
     
     long long leftFreq = (double) freq - ((double) bandwidth / 2.0);
     long long rightFreq = leftFreq + (double) bandwidth;
-    
-    long long firstMhz = (leftFreq / 1000000) * 1000000;
-    long double mhzStart = ((long double) (firstMhz - leftFreq) / (long double) (rightFreq - leftFreq)) * 2.0;
+
+    long long hzStep = 1000000;
     
     long double mhzStep = (100000.0 / (long double) (rightFreq - leftFreq)) * 2.0;
-    double mhzVisualStep = 0.1f;
-    
+    double mhzVisualStep = 0.1;
+
+    std::stringstream label;
+    label.precision(1);
+
     if (mhzStep * 0.5 * viewWidth < 40) {
         mhzStep = (250000.0 / (long double) (rightFreq - leftFreq)) * 2.0;
-        mhzVisualStep = 0.25f;
+        mhzVisualStep = 0.25;
+        label.precision(2);
     }
 
-    if (mhzStep * 0.5 * viewWidth > 400) {
+    if (mhzStep * 0.5 * viewWidth > 350) {
         mhzStep = (10000.0 / (long double) (rightFreq - leftFreq)) * 2.0;
-        mhzVisualStep = 0.01f;
+        mhzVisualStep = 0.01;
+        label.precision(2);
     }
-
-    long double currentMhz = trunc(floor(firstMhz / 1000000.0));
     
-    std::stringstream label;
-    label.precision(2);
+    long long firstMhz = (leftFreq / hzStep) * hzStep;
+    long double mhzStart = ((long double) (firstMhz - leftFreq) / (long double) (rightFreq - leftFreq)) * 2.0;
+    long double currentMhz = trunc(floor(firstMhz / (long double)1000000.0));
+    
     
     double hPos = 1.0 - (16.0 / viewHeight);
     double lMhzPos = 1.0 - (5.0 / viewHeight);
diff --git a/src/process/SpectrumVisualProcessor.cpp b/src/process/SpectrumVisualProcessor.cpp
index 9322462..8dc890d 100644
--- a/src/process/SpectrumVisualProcessor.cpp
+++ b/src/process/SpectrumVisualProcessor.cpp
@@ -14,7 +14,7 @@ SpectrumVisualProcessor::SpectrumVisualProcessor() : lastInputBandwidth(0), last
     
     fft_ceil_ma = fft_ceil_maa = 100.0;
     fft_floor_ma = fft_floor_maa = 0.0;
-    desiredInputSize = 0;
+    desiredInputSize.store(0);
     fft_average_rate = 0.65;
 }
 
@@ -27,19 +27,25 @@ bool SpectrumVisualProcessor::isView() {
 }
 
 void SpectrumVisualProcessor::setView(bool bView) {
+    busy_run.lock();
     is_view.store(bView);
+    busy_run.unlock();
 }
 
 void SpectrumVisualProcessor::setFFTAverageRate(float fftAverageRate) {
-    this->fft_average_rate = fftAverageRate;
+    busy_run.lock();
+    this->fft_average_rate.store(fftAverageRate);
+    busy_run.unlock();
 }
 
 float SpectrumVisualProcessor::getFFTAverageRate() {
-    return this->fft_average_rate;
+    return this->fft_average_rate.load();
 }
 
 void SpectrumVisualProcessor::setCenterFrequency(long long centerFreq_in) {
+    busy_run.lock();
     centerFreq.store(centerFreq_in);
+    busy_run.unlock();
 }
 
 long long SpectrumVisualProcessor::getCenterFrequency() {
@@ -47,7 +53,9 @@ long long SpectrumVisualProcessor::getCenterFrequency() {
 }
 
 void SpectrumVisualProcessor::setBandwidth(long bandwidth_in) {
+    busy_run.lock();
     bandwidth.store(bandwidth_in);
+    busy_run.unlock();
 }
 
 long SpectrumVisualProcessor::getBandwidth() {
@@ -55,12 +63,14 @@ long SpectrumVisualProcessor::getBandwidth() {
 }
 
 int SpectrumVisualProcessor::getDesiredInputSize() {
-    return desiredInputSize;
+    return desiredInputSize.load();
 }
 
 void SpectrumVisualProcessor::setup(int fftSize_in) {
+    busy_run.lock();
+
     fftSize = fftSize_in;
-    desiredInputSize = fftSize;
+    desiredInputSize.store(fftSize);
     
     if (fftwInput) {
         free(fftwInput);
@@ -82,7 +92,7 @@ void SpectrumVisualProcessor::setup(int fftSize_in) {
         fftwf_destroy_plan(fftw_plan);
     }
     fftw_plan = fftwf_plan_dft_1d(fftSize, fftwInput, fftwOutput, FFTW_FORWARD, FFTW_ESTIMATE);
-    
+    busy_run.unlock();
 }
 
 void SpectrumVisualProcessor::process() {
@@ -102,6 +112,7 @@ void SpectrumVisualProcessor::process() {
     }
     
     iqData->busy_rw.lock();
+    busy_run.lock();
     
     std::vector<liquid_float_complex> *data = &iqData->data;
     
@@ -118,6 +129,7 @@ void SpectrumVisualProcessor::process() {
             if (!iqData->frequency || !iqData->sampleRate) {
                 iqData->decRefCount();
                 iqData->busy_rw.unlock();
+                busy_run.unlock();
                 return;
             }
             
@@ -125,7 +137,7 @@ void SpectrumVisualProcessor::process() {
             
             int desired_input_size = fftSize / resamplerRatio;
             
-            this->desiredInputSize = desired_input_size;
+            this->desiredInputSize.store(desired_input_size);
             
             if (iqData->data.size() < desired_input_size) {
                 //                std::cout << "fft underflow, desired: " << desired_input_size << " actual:" << input->data.size() << std::endl;
@@ -304,5 +316,6 @@ void SpectrumVisualProcessor::process() {
  
     iqData->decRefCount();
     iqData->busy_rw.unlock();
+    busy_run.unlock();
 }
 
diff --git a/src/process/SpectrumVisualProcessor.h b/src/process/SpectrumVisualProcessor.h
index 8e1e694..149c170 100644
--- a/src/process/SpectrumVisualProcessor.h
+++ b/src/process/SpectrumVisualProcessor.h
@@ -53,7 +53,7 @@ private:
     
     double fft_ceil_ma, fft_ceil_maa;
     double fft_floor_ma, fft_floor_maa;
-    float fft_average_rate;
+    std::atomic<float> fft_average_rate;
     
     std::vector<double> fft_result;
     std::vector<double> fft_result_ma;
@@ -66,7 +66,8 @@ private:
     
     std::vector<liquid_float_complex> shiftBuffer;
     std::vector<liquid_float_complex> resampleBuffer;
-    int desiredInputSize;
+    std::atomic_int desiredInputSize;
+    std::mutex busy_run;
 };