diff --git a/release-packaging/Classes/FluidHPSS.sc b/release-packaging/Classes/FluidHPSS.sc
index c0040fa..7633063 100644
--- a/release-packaging/Classes/FluidHPSS.sc
+++ b/release-packaging/Classes/FluidHPSS.sc
@@ -1,12 +1,20 @@
 FluidHPSS : MultiOutUGen {
-	*ar { arg in = 0, percussiveFilterSize = 17, harmonicFilterSize = 17, percussiveThreshold = 50, harmonicThreshold = 50,  windowSize= 1024, hopSize= 256, fftSize= -1;
-		^this.multiNew('audio', in.asAudioRateInput(this),harmonicFilterSize,percussiveFilterSize,percussiveThreshold,harmonicThreshold,windowSize, hopSize, fftSize)
+	*ar { arg in = 0, percussiveFilterSize = 17, harmonicFilterSize=17, harmonicBinaryMask=0, percussiveBinaryMask=0,
+		percussiveThreshFreq1=0, percussiveThreshAmp1=0,percussiveThreshFreq2=1.0, percussiveThreshAmp2=0,
+		harmonicThreshFreq1=0, harmonicThreshAmp1=0, harmonicThreshFreq2=1.0, harmonicThreshAmp2=0,
+		windowSize= 1024, hopSize= 256, fftSize= -1;
+		^this.multiNew('audio', in.asAudioRateInput(this), percussiveFilterSize, harmonicFilterSize,
+			harmonicBinaryMask,percussiveBinaryMask,
+			percussiveThreshFreq1, percussiveThreshAmp1,percussiveThreshFreq2, percussiveThreshAmp2,
+			harmonicThreshFreq1, harmonicThreshAmp1, harmonicThreshFreq2, harmonicThreshAmp2,
+			windowSize, hopSize, fftSize)
 	}
 	init { arg ... theInputs;
 		inputs = theInputs;
 		channels = [
 			OutputProxy(rate, this, 0),
-			OutputProxy(rate, this, 1)
+			OutputProxy(rate, this, 1),
+			OutputProxy(rate, this, 2)
 		];
 		^channels
 	}
diff --git a/src/FluidHPSS/FluidHPSS.cpp b/src/FluidHPSS/FluidHPSS.cpp
index f097e7c..9f193c3 100644
--- a/src/FluidHPSS/FluidHPSS.cpp
+++ b/src/FluidHPSS/FluidHPSS.cpp
@@ -12,31 +12,25 @@ namespace hpss{
   {
     using AudioSignalWrapper = hpss::HPSSClient<double, float>::AudioSignal;
     using SignalWrapper      = hpss::HPSSClient<double, float>::Signal<float>;
-    
-    //  using SignalPointer = std::unique_ptr<signal_wrapper>;
+    using SignalPointer      = std::unique_ptr<SignalWrapper>;
+    using ClientPointer      = std::unique_ptr<hpss::HPSSClient<double,float>>;
+    template <size_t N>
+    using SignalArray        = std::array<SignalPointer,N>;
   public:
     FDRTHPSS()
     {
       //Order of args
       //psize hszie pthresh hthresh   Window size, Hop size, FFT Size
-      
-      //Get the window size
-//      const float hfilter_size = in0(1);
-//      const float pfilter_size = in0(2);
-//      const float window_size = in0(3);
-//      const float hop_size = in0(4);
-//      const float fft_size = in0(5);
-      
-      
+   
       //Oh NO! Heap allocation! Make client object
-      m_client =  new hpss::HPSSClient<double,float>(65536);
+      mClient =  ClientPointer(new hpss::HPSSClient<double,float>(65536));
       
       setParams(true);
       
       bool isOK;
       std::string feedback;
       
-      std::tie(isOK, feedback) = m_client->sanityCheck();
+      std::tie(isOK, feedback) = mClient->sanityCheck();
       if(!isOK)
       {
         Print("fdRTHPSS Error: %s",feedback.c_str());
@@ -44,37 +38,30 @@ namespace hpss{
       }
       
       
-      m_client->set_host_buffer_size(bufferSize());
-      m_client->reset();
+      mClient->set_host_buffer_size(bufferSize());
+      mClient->reset();
       
       //Work out what signals we need. For now keep it simple:
-      //in 0 => only audio
-      //out 0 => only audio
-      input_signals[0] =  new AudioSignalWrapper();
-      output_signals[0] = new AudioSignalWrapper();
-      output_signals[1] = new AudioSignalWrapper();
+      input_signals[0] =  SignalPointer(new AudioSignalWrapper());
+      output_signals[0] = SignalPointer(new AudioSignalWrapper());
+      output_signals[1] = SignalPointer(new AudioSignalWrapper());
+      output_signals[2] = SignalPointer(new AudioSignalWrapper());
       
       mCalcFunc = make_calc_function<FDRTHPSS,&FDRTHPSS::next>();
       Unit* unit = this;
       ClearUnitOutputs(unit,1);
     }
     
-    ~FDRTHPSS()
-    {
-      delete input_signals[0];
-      delete output_signals[0];
-      delete output_signals[1];
-      delete  m_client;
-    }
+    ~FDRTHPSS() {}
     
   private:
     
     void setParams(bool instantiation)
     {
-      assert(m_client);
-      for(size_t i = 0; i < m_client->getParams().size(); ++i)
+      assert(mClient);
+      for(size_t i = 0; i < mClient->getParams().size(); ++i)
       {
-        parameter::Instance& p = m_client->getParams()[i];
+        parameter::Instance& p = mClient->getParams()[i];
         if(!instantiation && p.getDescriptor().instantiation())
           continue;
         switch(p.getDescriptor().getType())
@@ -84,8 +71,25 @@ namespace hpss{
             p.checkRange();
             break;
           case parameter::Type::Float:
+          {
+            
+            //We need to constrain threshold (normalised) frequency pairs at runtime.
+            std::string attrname  = p.getDescriptor().getName();
+            auto constraint = paramConstraints.find(attrname);
+            
+            if(constraint != paramConstraints.end())
+            {
+              double limit = parameter::lookupParam(constraint->second.param, mClient->getParams()).getFloat();
+              
+              if(!constraint->second.condition(in0(i+1),limit))
+              {
+                return;
+              }
+            }
+            
             p.setFloat(in0(i+1));
             p.checkRange();
+          }
             break;
           case parameter::Type::Buffer:
             //            p.setBuffer( in0(i+1));
@@ -104,12 +108,26 @@ namespace hpss{
       input_signals[0]->set(const_cast<float*>(input), inscalar);
       output_signals[0]->set(out(0), out0(0));
       output_signals[1]->set(out(1), out0(1));
-      m_client->do_process(std::begin(input_signals),std::end(input_signals),std::begin(output_signals), std::end(output_signals),numsamples,1,2);
+      output_signals[2]->set(out(2), out0(2));
+      mClient->do_process(std::begin(input_signals),std::end(input_signals),std::begin(output_signals), std::end(output_signals),numsamples,1,3);
     }
     
-    hpss::HPSSClient<double, float>* m_client;
-    SignalWrapper* input_signals[1];
-    SignalWrapper*  output_signals[2];
+    struct Constraint{
+      std::string param;
+      std::function<bool(double, double)> condition;
+    };
+    
+    std::map<std::string, Constraint> paramConstraints{
+      {"pthreshf1",{"pthreshf2", std::less<double>()}},
+      {"hthreshf1",{"hthreshf2", std::less<double>()}},
+      {"pthreshf2",{"pthreshf1", std::greater<double>()}},
+      {"hthreshf2",{"hthreshf1", std::greater<double>()}}
+    };
+    
+
+    ClientPointer mClient;
+    SignalArray<1> input_signals;
+    SignalArray<3> output_signals;
   };
 }
 }