diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8d27a72..37b7739 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -24,6 +24,8 @@ set(FILES
 
         # Utils
         src/utils/CAllpassFilter.cpp
+        src/utils/CCombFilter.cpp
+        src/utils/CRevModel.cpp
         src/utils/Crossfeed.cpp
         src/utils/FixedBiquad.cpp
         src/utils/IIR_1st.cpp
diff --git a/include/hardware/audio_effect.h b/include/hardware/audio_effect.h
index 2955a23..d38e8ac 100644
--- a/include/hardware/audio_effect.h
+++ b/include/hardware/audio_effect.h
@@ -753,7 +753,7 @@ enum effect_command_e
 //--------------------------------------------------------------------------------------------------
 // description:
 //  1.indicate if the playback thread the effect is attached to is offloaded or not
-//  2.update the io handle of the playback thread the effect is attached to
+//  2.UpdateCoeffs the io handle of the playback thread the effect is attached to
 //--------------------------------------------------------------------------------------------------
 // command format:
 //  size: sizeof(effect_offload_param_t)
diff --git a/src/utils/CCombFilter.cpp b/src/utils/CCombFilter.cpp
new file mode 100644
index 0000000..0c0f34a
--- /dev/null
+++ b/src/utils/CCombFilter.cpp
@@ -0,0 +1,53 @@
+//
+// Created by mart on 7/27/21.
+//
+
+#include <cstring>
+#include "CCombFilter.h"
+
+CCombFilter::CCombFilter() {
+    this->buffer = nullptr;
+    this->size = 0;
+    this->bufidx = 0;
+    this->feedback = 0;
+    this->filterstore = 0;
+    this->damp = 0;
+    this->damp2 = 0;
+}
+
+float CCombFilter::Process(float sample) {
+    float output = this->buffer[this->bufidx];
+    this->filterstore = output * this->damp2 + this->filterstore * this->damp;;
+    this->buffer[this->bufidx] = sample + this->filterstore * this->feedback;
+    this->bufidx++;
+    if (this->bufidx >= this->size) {
+        this->bufidx = 0;
+    }
+    return output;
+}
+
+void CCombFilter::Mute() {
+    memset(this->buffer, 0, this->size * sizeof(float));
+}
+
+float CCombFilter::GetDamp() {
+    return this->damp;
+}
+
+float CCombFilter::GetFeedback() {
+    return this->feedback;
+}
+
+void CCombFilter::SetDamp(float damp) {
+    this->damp = damp;
+    this->damp2 = 1 - damp;
+}
+
+void CCombFilter::SetFeedback(float feedback) {
+    this->feedback = feedback;
+}
+
+void CCombFilter::SetBuffer(float *buffer, uint32_t size) {
+    this->buffer = buffer;
+    this->size = size;
+}
diff --git a/src/utils/CCombFilter.h b/src/utils/CCombFilter.h
new file mode 100644
index 0000000..5ee53bd
--- /dev/null
+++ b/src/utils/CCombFilter.h
@@ -0,0 +1,32 @@
+//
+// Created by mart on 7/27/21.
+//
+
+#pragma once
+
+#include <cstdint>
+
+class CCombFilter {
+public:
+    CCombFilter();
+
+    float Process(float sample);
+    void Mute();
+
+    float GetDamp();
+    float GetFeedback();
+    void SetDamp(float damp);
+    void SetFeedback(float feedback);
+    void SetBuffer(float* buffer, uint32_t size);
+
+    float feedback;
+    float filterstore;
+    float damp;
+    float damp2;
+    float* buffer;
+    uint32_t size;
+    uint32_t bufidx;
+};
+
+
+
diff --git a/src/utils/CRevModel.cpp b/src/utils/CRevModel.cpp
new file mode 100644
index 0000000..a3993e6
--- /dev/null
+++ b/src/utils/CRevModel.cpp
@@ -0,0 +1,202 @@
+//
+// Created by mart on 7/27/21.
+//
+
+#include "CRevModel.h"
+
+CRevModel::CRevModel() {
+    buffers[0] = new float[1116];
+    buffers[1] = new float[1139];
+    buffers[2] = new float[1188];
+    buffers[3] = new float[1211];
+    buffers[4] = new float[1277];
+    buffers[5] = new float[1300];
+    buffers[6] = new float[1356];
+    buffers[7] = new float[1379];
+    buffers[8] = new float[1356];
+    buffers[9] = new float[1445];
+    buffers[10] = new float[1491];
+    buffers[11] = new float[1514];
+    buffers[12] = new float[1557];
+    buffers[13] = new float[1580];
+    buffers[14] = new float[1617];
+    buffers[15] = new float[1640];
+    buffers[16] = new float[556];
+    buffers[17] = new float[579];
+    buffers[18] = new float[441];
+    buffers[19] = new float[464];
+    buffers[20] = new float[341];
+    buffers[21] = new float[364];
+    buffers[22] = new float[225];
+    buffers[23] = new float[248];
+
+    combL[0].SetBuffer(buffers[0], 1116);
+    combR[0].SetBuffer(buffers[1], 1139);
+    combL[1].SetBuffer(buffers[2], 1188);
+    combR[1].SetBuffer(buffers[3], 1211);
+    combL[2].SetBuffer(buffers[4], 1277);
+    combR[2].SetBuffer(buffers[5], 1300);
+    combL[3].SetBuffer(buffers[6], 1356);
+    combR[3].SetBuffer(buffers[7], 1379);
+    combL[4].SetBuffer(buffers[8], 1356);
+    combR[4].SetBuffer(buffers[9], 1445);
+    combL[5].SetBuffer(buffers[10], 1491);
+    combR[5].SetBuffer(buffers[11], 1514);
+    combL[6].SetBuffer(buffers[12], 1557);
+    combR[6].SetBuffer(buffers[13], 1580);
+    combL[7].SetBuffer(buffers[14], 1617);
+    combR[7].SetBuffer(buffers[15], 1640);
+    allpassL[0].SetBuffer(buffers[16], 556);
+    allpassR[0].SetBuffer(buffers[17], 579);
+    allpassL[1].SetBuffer(buffers[18], 441);
+    allpassR[1].SetBuffer(buffers[19], 464);
+    allpassL[2].SetBuffer(buffers[20], 341);
+    allpassR[2].SetBuffer(buffers[21], 364);
+    allpassL[3].SetBuffer(buffers[22], 225);
+    allpassR[3].SetBuffer(buffers[23], 248);
+
+    allpassL[0].SetFeedback(0.5f);
+    allpassR[0].SetFeedback(0.5f);
+    allpassL[1].SetFeedback(0.5f);
+    allpassR[1].SetFeedback(0.5f);
+    allpassL[2].SetFeedback(0.5f);
+    allpassR[2].SetFeedback(0.5f);
+    allpassL[3].SetFeedback(0.5f);
+    allpassR[3].SetFeedback(0.5f);
+
+    SetWet(1 / 3.f);
+    SetRoomSize(0.5f);
+    SetDry(0.f);
+    SetDamp(0.5f);
+    SetWidth(1.f);
+    SetMode(0.f);
+
+    Mute();
+}
+
+CRevModel::~CRevModel() {
+    for (int i = 0; i < 24; i++) {
+        delete[] buffers[i];
+    }
+}
+
+void CRevModel::Mute() {
+    if (mode == 1) {
+        return;
+    }
+
+    for (int i=0; i<8; i++) {
+        combL[i].Mute();
+        combR[i].Mute();
+    }
+    for (int i=0; i<4; i++) {
+        allpassL[i].Mute();
+        allpassR[i].Mute();
+    }
+}
+
+void CRevModel::ProcessReplace(float *bufL, float *bufR, uint32_t size) {
+    for (int idx = 0; idx < size; idx++) {
+        float outL = 0.f;
+        float outR = 0.f;
+        float input = (*bufL + *bufR) * gain;
+
+        for (int i=0; i<8; i++) {
+            outL += combL[i].Process(input);
+            outR += combR[i].Process(input);
+        }
+
+        for (int i=0; i<4; i++) {
+            outL = allpassL[i].Process(outL);
+            outR = allpassR[i].Process(outR);
+        }
+
+        *bufL = outL*wet1 + outR*wet2 + *bufL * dry;
+        *bufR = outR*wet1 + outL*wet2 + *bufR * dry;
+
+        bufL += 1;
+        bufR += 1;
+    }
+}
+
+void CRevModel::UpdateCoeffs() {
+    wet1 = wet*(width/2.f + 0.5f);
+    wet2 = wet*((1.f-width)/2.f);
+
+    if (mode == 1) {
+        roomsize1 = 1.f;
+        damp1 = 0.f;
+        gain = 0.f;
+    } else {
+        roomsize1 = roomsize;
+        damp1 = damp;
+        gain = 0.015f;
+    }
+
+    for (int i=0; i<8; i++) {
+        combL[i].SetFeedback(roomsize1);
+        combR[i].SetFeedback(roomsize1);
+    }
+
+    for(int i=0; i<8; i++) {
+        combL[i].SetDamp(damp1);
+        combR[i].SetDamp(damp1);
+    }
+}
+
+void CRevModel::SetRoomSize(float value) {
+    roomsize = (value*0.28f) + 0.7f;
+    UpdateCoeffs();
+}
+
+void CRevModel::SetDamp(float value) {
+    damp = value*0.4f;
+    UpdateCoeffs();
+}
+
+void CRevModel::SetWet(float value) {
+    wet = value*3.f;
+    UpdateCoeffs();
+}
+
+void CRevModel::SetDry(float value) {
+    dry = value*2.f;
+}
+
+void CRevModel::SetWidth(float value) {
+    width = value;
+    UpdateCoeffs();
+}
+
+void CRevModel::SetMode(int value) {
+    mode = value;
+    UpdateCoeffs();
+}
+
+float CRevModel::GetRoomSize() {
+    return (roomsize-0.7f)/0.28f;
+}
+
+float CRevModel::GetDamp() {
+    return damp/0.4f;
+}
+
+float CRevModel::GetWet() {
+    return wet/3.f;
+}
+
+float CRevModel::GetDry() {
+    return dry/2.f;
+}
+
+float CRevModel::GetWidth() {
+    return width;
+}
+
+float CRevModel::GetMode() {
+    if (mode == 1) {
+        return 1.f;
+    } else {
+        return 0.f;
+    }
+}
diff --git a/src/utils/CRevModel.h b/src/utils/CRevModel.h
new file mode 100644
index 0000000..30b3209
--- /dev/null
+++ b/src/utils/CRevModel.h
@@ -0,0 +1,54 @@
+//
+// Created by mart on 7/27/21.
+//
+
+#pragma once
+
+#include "CCombFilter.h"
+#include "CAllpassFilter.h"
+
+class CRevModel {
+public:
+    CRevModel();
+    ~CRevModel();
+
+    void Mute();
+    void ProcessReplace(float *bufL, float *bufR, uint32_t size);
+    void UpdateCoeffs();
+
+    void SetRoomSize(float value);
+    void SetDamp(float value);
+    void SetWet(float value);
+    void SetDry(float value);
+    void SetWidth(float value);
+    void SetMode(int value);
+    float GetRoomSize();
+    float GetDamp();
+    float GetWet();
+    float GetDry();
+    float GetWidth();
+    int GetMode();
+
+    float gain;
+    float roomsize;
+    float roomsize1;
+    float damp;
+    float damp1;
+    float wet;
+    float wet1;
+    float wet2;
+    float dry;
+    float width;
+    int mode;
+
+    CCombFilter combL[8];
+    CCombFilter combR[8];
+
+    CAllpassFilter allpassL[4];
+    CAllpassFilter allpassR[4];
+
+    float* buffers[24];
+};
+
+
+