diff --git a/lib/audiodev/AudioMatrix.hpp b/lib/audiodev/AudioMatrix.hpp
index 9cd4dc3..90a559d 100644
--- a/lib/audiodev/AudioMatrix.hpp
+++ b/lib/audiodev/AudioMatrix.hpp
@@ -5,6 +5,7 @@
 #include <vector>
 #include <stdint.h>
 #include <limits.h>
+#include <float.h>
 
 #if __SSE__
 #include <xmmintrin.h>
@@ -74,6 +75,18 @@ public:
                                const int32_t* dataIn, int32_t* dataOut, size_t samples);
     float* mixMonoSampleData(const AudioVoiceEngineMixInfo& info,
                              const float* dataIn, float* dataOut, size_t samples);
+
+    bool isSilent() const
+    {
+        if (m_curSlewFrame < m_slewFrames)
+            for (int i=0 ; i<8 ; ++i)
+                if (m_oldCoefs.v[i] > FLT_EPSILON)
+                    return false;
+        for (int i=0 ; i<8 ; ++i)
+            if (m_coefs.v[i] > FLT_EPSILON)
+                return false;
+        return true;
+    }
 };
 
 class AudioMatrixStereo
@@ -124,6 +137,18 @@ public:
                                  const int32_t* dataIn, int32_t* dataOut, size_t frames);
     float* mixStereoSampleData(const AudioVoiceEngineMixInfo& info,
                                const float* dataIn, float* dataOut, size_t frames);
+
+    bool isSilent() const
+    {
+        if (m_curSlewFrame < m_slewFrames)
+            for (int i=0 ; i<8 ; ++i)
+                if (m_oldCoefs.v[i][0] > FLT_EPSILON || m_oldCoefs.v[i][1] > FLT_EPSILON)
+                    return false;
+        for (int i=0 ; i<8 ; ++i)
+            if (m_coefs.v[i][0] > FLT_EPSILON || m_coefs.v[i][1] > FLT_EPSILON)
+                return false;
+        return true;
+    }
 };
 
 }
diff --git a/lib/audiodev/AudioVoice.cpp b/lib/audiodev/AudioVoice.cpp
index de7a5c4..7d2e5c2 100644
--- a/lib/audiodev/AudioVoice.cpp
+++ b/lib/audiodev/AudioVoice.cpp
@@ -125,6 +125,18 @@ size_t AudioVoiceMono::SRCCallback(AudioVoiceMono* ctx, int16_t** data, size_t f
 
 size_t AudioVoiceMono::pumpAndMix16(size_t frames)
 {
+    if (m_sendMatrices.size())
+    {
+        for (auto& mtx : m_sendMatrices)
+            if (mtx.second.isSilent())
+                return 0;
+    }
+    else
+    {
+        if (DefaultMonoMtx.isSilent())
+            return 0;
+    }
+
     std::vector<int16_t>& scratch16Pre = m_root.m_scratch16Pre;
     if (scratch16Pre.size() < frames)
         scratch16Pre.resize(frames);
@@ -162,6 +174,18 @@ size_t AudioVoiceMono::pumpAndMix16(size_t frames)
 
 size_t AudioVoiceMono::pumpAndMix32(size_t frames)
 {
+    if (m_sendMatrices.size())
+    {
+        for (auto& mtx : m_sendMatrices)
+            if (mtx.second.isSilent())
+                return 0;
+    }
+    else
+    {
+        if (DefaultMonoMtx.isSilent())
+            return 0;
+    }
+
     std::vector<int32_t>& scratch32Pre = m_root.m_scratch32Pre;
     if (scratch32Pre.size() < frames)
         scratch32Pre.resize(frames);
@@ -199,6 +223,18 @@ size_t AudioVoiceMono::pumpAndMix32(size_t frames)
 
 size_t AudioVoiceMono::pumpAndMixFlt(size_t frames)
 {
+    if (m_sendMatrices.size())
+    {
+        for (auto& mtx : m_sendMatrices)
+            if (mtx.second.isSilent())
+                return 0;
+    }
+    else
+    {
+        if (DefaultMonoMtx.isSilent())
+            return 0;
+    }
+
     std::vector<float>& scratchFltPre = m_root.m_scratchFltPre;
     if (scratchFltPre.size() < frames)
         scratchFltPre.resize(frames + 2);
@@ -326,6 +362,18 @@ size_t AudioVoiceStereo::SRCCallback(AudioVoiceStereo* ctx, int16_t** data, size
 
 size_t AudioVoiceStereo::pumpAndMix16(size_t frames)
 {
+    if (m_sendMatrices.size())
+    {
+        for (auto& mtx : m_sendMatrices)
+            if (mtx.second.isSilent())
+                return 0;
+    }
+    else
+    {
+        if (DefaultMonoMtx.isSilent())
+            return 0;
+    }
+
     size_t samples = frames * 2;
 
     std::vector<int16_t>& scratch16Pre = m_root.m_scratch16Pre;
@@ -365,6 +413,18 @@ size_t AudioVoiceStereo::pumpAndMix16(size_t frames)
 
 size_t AudioVoiceStereo::pumpAndMix32(size_t frames)
 {
+    if (m_sendMatrices.size())
+    {
+        for (auto& mtx : m_sendMatrices)
+            if (mtx.second.isSilent())
+                return 0;
+    }
+    else
+    {
+        if (DefaultMonoMtx.isSilent())
+            return 0;
+    }
+
     size_t samples = frames * 2;
 
     std::vector<int32_t>& scratch32Pre = m_root.m_scratch32Pre;
@@ -404,6 +464,18 @@ size_t AudioVoiceStereo::pumpAndMix32(size_t frames)
 
 size_t AudioVoiceStereo::pumpAndMixFlt(size_t frames)
 {
+    if (m_sendMatrices.size())
+    {
+        for (auto& mtx : m_sendMatrices)
+            if (mtx.second.isSilent())
+                return 0;
+    }
+    else
+    {
+        if (DefaultMonoMtx.isSilent())
+            return 0;
+    }
+
     size_t samples = frames * 2;
 
     std::vector<float>& scratchFltPre = m_root.m_scratchFltPre;