diff --git a/src/param.hpp b/src/param.hpp
new file mode 100644
index 0000000..6ac5e71
--- /dev/null
+++ b/src/param.hpp
@@ -0,0 +1,205 @@
+#include <sys/types.h>
+#include <string>
+#include <cmath>
+
+class Param
+{
+	std::string m_name;
+	std::string m_unit;
+	typedef struct _sparam_info_t
+	{
+		double pmin, pmax, pvalue, pinterval, pcenter, scenter, base, kexp;
+
+	} param_info_t;
+	
+	param_info_t m_param_info;
+
+	public:
+
+
+	Param(
+		std::string name,
+		std::string unit,
+		double pmin,
+		double pmax,
+		double pvalue,
+		double pinterval=1.0,
+		double pcenter=-1.0,
+		double scenter=0.0,
+		double base=1.0,
+		double kexp=1.0
+	)
+	: m_name(name)
+	, m_param_info({pmin, pmax, pvalue, pinterval, pcenter, scenter, base, kexp})
+	{
+
+	}
+
+	std::string name()
+	{
+		return m_name;
+	}
+
+	std::string unit()
+	{
+		return m_unit;
+	}
+
+	double getParameter()
+	{
+		return m_param_info.pvalue;
+	}
+
+	void setParameter(double p)
+	{
+		m_param_info.pvalue = p;
+	}
+
+	double getSlider()
+	{
+		return toSlider();
+	}
+	
+	// --------------------------------------------------------------
+	// Exported functions
+	// --------------------------------------------------------------
+	double quantizeParam(double p)
+	{
+		double k, pq;
+		if (m_param_info.pinterval == 0)
+		{
+			return p;
+		}
+
+		k = (double)1/(m_param_info.pinterval - 0);
+
+		if (p < 0)
+		{
+			pq = ((int)(p*k - 0.5))*m_param_info.pinterval;
+		}
+		else
+		{
+			pq = ((int)(p*k + 0.5))*m_param_info.pinterval;
+		}
+
+		return pq;
+	}
+
+	double clampParam(double p)
+	{
+		return (double)std::min(m_param_info.pmax, std::max(m_param_info.pmin, quantizeParam(p)));
+	}
+
+	double fromSlider(double s)
+	{
+		double p, pcenter;
+		double pmax, pmin, base, kexp, scenter;
+
+		pmax = m_param_info.pmax;
+		pmin = m_param_info.pmin;
+		if (pmin == pmax)
+		{
+			pmax += 1E-9;
+		}
+		base = m_param_info.base;
+		kexp = m_param_info.kexp;
+		if (kexp == 0)
+		{
+			kexp = 1E-9;
+		}
+		scenter = m_param_info.scenter;
+		pcenter = m_param_info.pcenter;
+
+		if ((pcenter < pmin) || (pcenter > pmax))
+			pcenter = pmax*scenter + pmin*(1-scenter);
+
+		s = (double)std::min(1.0, std::max(0.0, s));
+		if (s < scenter)
+		{
+			if (base == 1)
+			{
+				// pcenter-(pcenter-pmin)*(scenter-s)/scenter;
+				p = pcenter-(pcenter-pmin)*(scenter-s)/scenter;
+			}
+			else
+			{
+				// pcenter-(pcenter-pmin)*(B^(k*(scenter-s)/scenter)-1)/(B^k-1);
+				p = pcenter-(pcenter-pmin)*(pow(base,kexp*(scenter-s)/scenter)-1)/(pow(base,kexp)-1);
+			}
+		}
+		else
+		{
+			if (base == 1)
+			{
+				// pcenter+(pmax-pcenter)*(-scenter+s)/(1-scenter);
+				p = pcenter+(pmax-pcenter)*(-scenter+s)/(1-scenter);
+			}
+			else
+			{
+				// pcenter+(pmax-pcenter)*(B^(k*(-scenter+s)/(1-scenter))-1)/(B^k-1);
+				p = pcenter+(pmax-pcenter)*(pow(base,kexp*(-scenter+s)/(1-scenter))-1)/(pow(base,kexp)-1);
+			}
+		}
+
+		m_param_info.pvalue = p;
+		return quantizeParam(p);
+	}
+
+	double toSlider()
+	{
+		double p = m_param_info.pvalue;
+
+		double s, pcenter;
+		double pmax, pmin, base, kexp, scenter;
+
+		pmax = m_param_info.pmax;
+		pmin = m_param_info.pmin;
+		if (pmin == pmax)
+		{
+			pmax += 1E-9;
+		}
+		base = m_param_info.base;
+		kexp = m_param_info.kexp;
+		if (kexp == 0)
+		{
+			kexp = 1E-9;
+		}
+		scenter = m_param_info.scenter;
+		pcenter = m_param_info.pcenter;
+
+		if ((pcenter < pmin) || (pcenter > pmax))
+		{
+			pcenter = pmax*scenter + pmin*(1-scenter);
+		}
+
+		p = clampParam(p);
+		if (p < pcenter)
+		{
+			if (base == 1)
+			{
+				// (-pmin+p)*scenter/(pcenter-pmin);
+				s = (-pmin+p)*scenter/(pcenter-pmin);
+			}
+			else
+			{
+				// scenter*(log(B)*k-log(-(-pcenter*B^k+pmin+p*B^k-p)/(pcenter-pmin)))/log(B)/k;
+				s = scenter*(log(base)*kexp-log(-(-pcenter*pow(base,kexp)+pmin+p*pow(base,kexp)-p)/(pcenter-pmin)))/log(base)/kexp;
+			}
+		}
+		else
+		{
+			if (base == 1)
+			{
+				// (pcenter-scenter*pmax-p+scenter*p)/(-pmax+pcenter);
+				s = (pcenter-scenter*pmax-p+scenter*p)/(-pmax+pcenter);
+			}
+			else
+			{
+				// (k*log(B)*scenter+log(-(-pcenter*B^k+pmax+p*B^k-p)/(-pmax+pcenter))-log(-(-pcenter*B^k+pmax+p*B^k-p)/(-pmax+pcenter))*scenter)/log(B)/k;
+				s = (kexp*log(base)*scenter+log(-(-pcenter*pow(base,kexp)+pmax+p*pow(base,kexp)-p)/(-pmax+pcenter))-log(-(-pcenter*pow(base,kexp)+pmax+p*pow(base,kexp)-p)/(-pmax+pcenter))*scenter)/log(base)/kexp;
+			}
+		}
+
+		return s;
+	}
+};
diff --git a/src/plugin.cpp b/src/plugin.cpp
index 4288152..c573943 100755
--- a/src/plugin.cpp
+++ b/src/plugin.cpp
@@ -9,33 +9,8 @@
 #include <cstdlib>
 #include <cstdio>
 
-#define NUM_PARMS	8
 #define MAX_ORDER	4
 
-const char * const pFTypeString[] =
-{
-	"Order",
-	"Size 1",
-    "Size 2",
-	"Size 3",
-	"Size 4",
-	"Feedback Delay Min",
-	"Feedback Delay Max",
-	"Feedback Gain",
-};
-
-const char * const pFUnitString[] =
-{
-	"",
-	"samples",
-    "samples",
-	"samples",
-	"samples",
-	"samples",
-	"samples",
-	"",
-};
-
 enum {ORDER, SIZE_1, SIZE_2, SIZE_3, SIZE_4, FEEDBACK_DELAY_MIN, FEEDBACK_DELAY_XAX, FEEDBACK_GAIN};
 
 AudioEffect* createEffectInstance (audioMasterCallback audioMaster)
@@ -59,6 +34,15 @@ Plugin::Plugin(audioMasterCallback audioMaster)
 
 	m_feedback_delay[0] = 0;
 	m_feedback_delay[1] = 0;
+
+	m_params[0] = new Param("Order", "", 0, 4, 4);
+	m_params[1] = new Param("Delay 1", "ms", 0, 1000, 50);
+	m_params[2] = new Param("Delay 2", "ms", 0, 1000, 100);
+	m_params[3] = new Param("Delay 3", "ms", 0, 1000, 250);
+	m_params[4] = new Param("Delay 4", "ms", 0, 1000, 500);
+	m_params[5] = new Param("Feedback Delay Min", "ms", 0, 1000, 100);
+	m_params[6] = new Param("Feedback Delay Max", "ms", 0, 1000, 200);
+	m_params[7] = new Param("Feedback Gain", "%", 0, 100, 0);
 }
 
 //-----------------------------------------------------------------------------------------
@@ -84,31 +68,39 @@ void Plugin::setParameter(VstInt32 index, float value)
 {
 	switch(index)
 	{
-	case ORDER:
-		break;
+		case ORDER:
+			break;
 
-	case SIZE_1:
-	case SIZE_2:
-	case SIZE_3:
-	case SIZE_4:
-	{
-		uint delay = (uint)(value*DELAY_MAX);
-		m_reverb_1.setDelay(delay, index - SIZE_1);
-		m_reverb_2.setDelay(delay, index - SIZE_1);
-		break;
-	}
+		case SIZE_1:
+		case SIZE_2:
+		case SIZE_3:
+		case SIZE_4:
+		{
+			double p = m_params[index]->fromSlider(value);
+			uint delay = (uint)(p*sampleRate/1000);
+			m_reverb_1.setDelay(delay, index - SIZE_1);
+			m_reverb_2.setDelay(delay, index - SIZE_1);
+			break;
+		}
 
-	case FEEDBACK_GAIN:
-		m_reverb_1.setFeedbackGain(value);
-		m_reverb_2.setFeedbackGain(value);
-		break;
+		case FEEDBACK_GAIN:
+		{
+			double p = m_params[index]->fromSlider(value)/100;
+			m_reverb_1.setFeedbackGain(p);
+			m_reverb_2.setFeedbackGain(p);
+			break;
+		}
 
-	case FEEDBACK_DELAY_MIN:
-	case FEEDBACK_DELAY_XAX:
-		m_feedback_delay[index-FEEDBACK_DELAY_MIN] = (uint)(value * DELAY_MAX);
-		m_reverb_1.setFeedbackDelay(m_feedback_delay[0], m_feedback_delay[1]);
-		m_reverb_2.setFeedbackDelay(m_feedback_delay[0], m_feedback_delay[1]);
-		break;
+		case FEEDBACK_DELAY_MIN:
+		case FEEDBACK_DELAY_XAX:
+		{
+			double p = m_params[index]->fromSlider(value);
+			uint delay = (uint)(p*sampleRate/1000);
+			m_feedback_delay[index-FEEDBACK_DELAY_MIN] = delay;
+			m_reverb_1.setFeedbackDelay(m_feedback_delay[0], m_feedback_delay[1]);
+			m_reverb_2.setFeedbackDelay(m_feedback_delay[0], m_feedback_delay[1]);
+			break;
+		}
 		
 	}
 
@@ -122,23 +114,14 @@ float Plugin::getParameter(VstInt32 index)
 	switch(index)
 	{
 	case ORDER:
-		value = (float)MAX_ORDER;
-		break;
-
 	case SIZE_1:
 	case SIZE_2:
 	case SIZE_3:
 	case SIZE_4:
-		value = m_reverb_1.getDelay(index - SIZE_1);
-		break;
-
 	case FEEDBACK_GAIN:
-		value = m_reverb_1.getFeedbackGain();
-		break;
-
 	case FEEDBACK_DELAY_MIN:
 	case FEEDBACK_DELAY_XAX:
-		value = m_feedback_delay[index-FEEDBACK_DELAY_MIN];
+		value = m_params[index]->getSlider();
 		break;
 
 
@@ -159,7 +142,7 @@ void Plugin::getParameterName(VstInt32 index, char *label)
 		case FEEDBACK_DELAY_MIN:
 		case FEEDBACK_DELAY_XAX:
 		case FEEDBACK_GAIN:
-			strcpy(label,pFTypeString[index]);
+			strcpy(label,m_params[index]->name().c_str());
 			break;
 		default:
 			strcpy(label,"Unknown");
@@ -180,10 +163,8 @@ void Plugin::getParameterDisplay(VstInt32 index, char *text)
 		case SIZE_4:
 		case FEEDBACK_DELAY_MIN:
 		case FEEDBACK_DELAY_XAX:
-			sprintf(text, "%d", (int)getParameter(index));
-			break;
 		case FEEDBACK_GAIN:
-			sprintf(text, "%f", getParameter(index));
+			sprintf(text, "%f", m_params[index]->getParameter());
 			break;
 	}
 }
@@ -201,7 +182,7 @@ void Plugin::getParameterLabel(VstInt32 index, char *label)
 		case FEEDBACK_DELAY_MIN:
 		case FEEDBACK_DELAY_XAX:
 		case FEEDBACK_GAIN:
-			strcpy(label, pFUnitString[index]);
+			strcpy(label,m_params[index]->unit().c_str());
 			break;
 	}
 }
diff --git a/src/plugin.hpp b/src/plugin.hpp
index 8677ff2..d235cc7 100755
--- a/src/plugin.hpp
+++ b/src/plugin.hpp
@@ -8,10 +8,12 @@
 
 #include "public.sdk/source/vst2.x/audioeffectx.h"
 #include <reverb/reverb.hpp>
+#include "param.hpp"
 
 class Plugin : public AudioEffectX
 {
-	const uint DELAY_MAX = 48000;
+	static const uint DELAY_MAX = 48000;
+	static const uint NUM_PARMS = 8;
 
 	public:
 	Plugin(audioMasterCallback audioMaster);
@@ -42,6 +44,7 @@ private:
 	Reverb<float, 8> m_reverb_1;
 	Reverb<float, 8> m_reverb_2;
 	uint m_feedback_delay[2];
+	Param *m_params[NUM_PARMS];
 };
 
 #endif // __PLUGIN_H