diff --git a/config/radar4.yml b/config/radar4.yml
index 07d8d96..5473f12 100644
--- a/config/radar4.yml
+++ b/config/radar4.yml
@@ -35,6 +35,6 @@ network:
 
 save:
   iq: true
-  map: true
+  map: false
   detection: false
-  path: "/opt/blah2/"
+  path: "/blah2/save/"
diff --git a/src/blah2.cpp b/src/blah2.cpp
index 16d31d0..d221608 100644
--- a/src/blah2.cpp
+++ b/src/blah2.cpp
@@ -169,15 +169,15 @@ int main(int argc, char **argv)
           auto t0 = std::chrono::high_resolution_clock::now();
           
           // extract data from buffer
-          buffer1->set_doNotPush(true);
-          buffer2->set_doNotPush(true);
+          buffer1->lock();
+          buffer2->lock();
           for (int i = 0; i < nSamples; i++)
           {
             x->push_back(buffer1->pop_front());
             y->push_back(buffer2->pop_front());
           }
-          buffer1->set_doNotPush(false);
-          buffer2->set_doNotPush(false);
+          buffer1->unlock();
+          buffer2->unlock();
           auto t1 = std::chrono::high_resolution_clock::now();
           double delta_t1 = std::chrono::duration<double, std::milli>(t1-t0).count();
           std::cout << "Extract data from buffer (ms): " << delta_t1 << std::endl;
diff --git a/src/capture/rspduo/RspDuo.cpp b/src/capture/rspduo/RspDuo.cpp
index 2d69d14..b9f168a 100644
--- a/src/capture/rspduo/RspDuo.cpp
+++ b/src/capture/rspduo/RspDuo.cpp
@@ -131,11 +131,18 @@ void RspDuo::replay(IqData *_buffer1, IqData *_buffer2, std::string _file, bool
     rv = fread(&i2, 1, sizeof(short), file_replay);
     rv = fread(&q2, 1, sizeof(short), file_replay);
 
-    if (!buffer1->get_doNotPush() & buffer1->get_length() < buffer1->get_n())
+    buffer1->lock();
+    buffer2->lock();
+
+    if (buffer1->get_length() < buffer1->get_n())
     {
       buffer1->push_back({(double)i1, (double)q1});
       buffer2->push_back({(double)i2, (double)q2});
     }
+
+    buffer1->unlock();
+    buffer2->unlock();
+
   }
 
 }
@@ -508,12 +515,6 @@ void RspDuo::stream_a_callback(short *xi, short *xq, sdrplay_api_StreamCbParamsT
     // skip tuner B data
     j++;
     j++;
-
-    if (!buffer1->get_doNotPush())
-    {
-      buffer1->push_back({(double)xi[i], (double)xq[i]});
-      //buffer2->push_back({(double)xi[i], (double)xq[i]});
-    }
   }
 
   // find max for stats
@@ -545,13 +546,19 @@ void RspDuo::stream_b_callback(short *xi, short *xq, sdrplay_api_StreamCbParamsT
     // add tuner B data
     buffer_16_ar[j++] = xi[i];
     buffer_16_ar[j++] = xq[i];
-
-    if (!buffer2->get_doNotPush())
-    {
-      buffer2->push_back({(double)xi[i], (double)xq[i]});
-    }
   }
 
+  // write data to IqData
+  buffer1->lock();
+  buffer2->lock();
+  for (int i = 0; i < numSamples*4; i+=4)
+  {
+    buffer1->push_back({(double)buffer_16_ar[i], (double)buffer_16_ar[i+1]});
+    buffer2->push_back({(double)buffer_16_ar[i+2], (double)buffer_16_ar[i+3]});
+  }
+  buffer1->unlock();
+  buffer2->unlock();
+
   // decide if to write data
   gettimeofday(&current_tm, NULL);
 
diff --git a/src/data/IqData.cpp b/src/data/IqData.cpp
index af9703e..99fa92d 100644
--- a/src/data/IqData.cpp
+++ b/src/data/IqData.cpp
@@ -6,7 +6,6 @@
 IqData::IqData(uint32_t _n)
 {
   n = _n;
-  doNotPush = false;
   data = new std::deque<std::complex<double>>;
 }
 
@@ -15,19 +14,19 @@ uint32_t IqData::get_n()
   return n;
 }
 
-void IqData::set_doNotPush(bool _doNotPush)
-{
-  doNotPush = _doNotPush;
-}
-
 uint32_t IqData::get_length()
 {
   return data->size();
 }
 
-bool IqData::get_doNotPush()
+void IqData::lock()
 {
-  return doNotPush;
+  mutex_lock.lock();
+}
+
+void IqData::unlock()
+{
+  mutex_lock.unlock();
 }
 
 std::deque<std::complex<double>> IqData::get_data()
diff --git a/src/data/IqData.h b/src/data/IqData.h
index 0c020f0..831ff6c 100644
--- a/src/data/IqData.h
+++ b/src/data/IqData.h
@@ -10,6 +10,7 @@
 #include <stdint.h>
 #include <deque>
 #include <complex>
+#include <mutex>
 
 class IqData
 {
@@ -18,7 +19,7 @@ private:
   uint32_t n;
 
   /// @brief True if should not push to buffer (mutex).
-  bool doNotPush;
+  std::mutex mutex_lock;
 
   /// @brief Pointer to IQ data.
   std::deque<std::complex<double>> *data;
@@ -37,14 +38,13 @@ public:
   /// @return Number of samples currently in data.
   uint32_t get_length();
 
-  /// @brief Setter for mutex.
-  /// @param doNotPush True if should not push to buffer (mutex).
+  /// @brief Locker for mutex.
   /// @return Void.
-  void set_doNotPush(bool doNotPush);
+  void lock();
 
-  /// @brief Getter for mutex.
-  /// @return True if should not push to buffer (mutex).
-  bool get_doNotPush();
+  /// @brief Unlocker for mutex.
+  /// @return Void.
+  void unlock();
 
   /// @brief Getter for data.
   /// @return IQ data.