diff --git a/include/EffectChain.h b/include/EffectChain.h
index b09863896..620caa427 100644
--- a/include/EffectChain.h
+++ b/include/EffectChain.h
@@ -2,7 +2,7 @@
  * EffectChain.h - class for processing and effects chain
  *
  * Copyright (c) 2006-2008 Danny McRae <khjklujn/at/users.sourceforge.net>
- * Copyright (c) 2008-2009 Tobias Doerffel <tobydox/at/users.sourceforge.net>
+ * Copyright (c) 2008-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
  *
  * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
  *
@@ -53,7 +53,7 @@ public:
 	void removeEffect( Effect * _effect );
 	void moveDown( Effect * _effect );
 	void moveUp( Effect * _effect );
-	bool processAudioBuffer( sampleFrame * _buf, const fpp_t _frames );
+	bool processAudioBuffer( sampleFrame * _buf, const fpp_t _frames, bool hasInputNoise );
 	void startRunning();
 	bool isRunning();
 
diff --git a/src/core/EffectChain.cpp b/src/core/EffectChain.cpp
index e38c946fe..83268950e 100644
--- a/src/core/EffectChain.cpp
+++ b/src/core/EffectChain.cpp
@@ -184,17 +184,21 @@ void EffectChain::moveUp( Effect * _effect )
 
 
 
-bool EffectChain::processAudioBuffer( sampleFrame * _buf, const fpp_t _frames )
+bool EffectChain::processAudioBuffer( sampleFrame * _buf, const fpp_t _frames, bool hasInputNoise )
 {
 	if( m_enabledModel.value() == false )
 	{
 		return false;
 	}
+
 	bool moreEffects = false;
-	for( EffectList::Iterator it = m_effects.begin(); 
-						it != m_effects.end(); ++it )
+	for( EffectList::Iterator it = m_effects.begin(); it != m_effects.end(); ++it )
 	{
-		moreEffects |= ( *it )->processAudioBuffer( _buf, _frames );
+		if( hasInputNoise || ( *it )->isRunning() )
+		{
+			moreEffects |= ( *it )->processAudioBuffer( _buf, _frames );
+		}
+
 #ifdef LMMS_DEBUG
 		for( int f = 0; f < _frames; ++f )
 		{
@@ -209,6 +213,7 @@ bool EffectChain::processAudioBuffer( sampleFrame * _buf, const fpp_t _frames )
 		}
 #endif
 	}
+
 	return moreEffects;
 }
 
diff --git a/src/core/FxMixer.cpp b/src/core/FxMixer.cpp
index a87a23392..ab294c747 100644
--- a/src/core/FxMixer.cpp
+++ b/src/core/FxMixer.cpp
@@ -1,10 +1,8 @@
-#ifndef SINGLE_SOURCE_COMPILE
-
 /*
  * FxMixer.cpp - effect mixer for LMMS
  *
  * Copyright (c) 2008-2011 Tobias Doerffel <tobydox/at/users.sourceforge.net>
- * 
+ *
  * This file is part of Linux MultiMedia Studio - http://lmms.sourceforge.net
  *
  * This program is free software; you can redistribute it and/or
@@ -118,8 +116,15 @@ void FxMixer::processChannel( fx_ch_t _ch, sampleFrame * _buf )
 		const fpp_t f = engine::mixer()->framesPerPeriod();
 		if( !engine::getSong()->isFreezingPattern() )
 		{
-			m_fxChannels[_ch]->m_fxChain.startRunning();
-			m_fxChannels[_ch]->m_stillRunning = m_fxChannels[_ch]->m_fxChain.processAudioBuffer( _buf, f );
+			// only start effects if sound was mixed to this FX channel before
+			if( m_fxChannels[_ch]->m_used )
+			{
+				m_fxChannels[_ch]->m_fxChain.startRunning();
+			}
+
+			// process FX chain
+			m_fxChannels[_ch]->m_stillRunning = m_fxChannels[_ch]->m_fxChain.processAudioBuffer( _buf, f, m_fxChannels[_ch]->m_used );
+
 			float peakLeft = engine::mixer()->peakValueLeft( _buf, f ) * m_fxChannels[_ch]->m_volumeModel.value();
 			float peakRight = engine::mixer()->peakValueRight( _buf, f ) * m_fxChannels[_ch]->m_volumeModel.value();
 
diff --git a/src/core/audio/AudioPort.cpp b/src/core/audio/AudioPort.cpp
index b8f909b40..cdcf675b7 100644
--- a/src/core/audio/AudioPort.cpp
+++ b/src/core/audio/AudioPort.cpp
@@ -109,8 +109,8 @@ bool AudioPort::processEffects()
 	if( m_effects )
 	{
 		lockFirstBuffer();
-		bool more = m_effects->processAudioBuffer( m_firstBuffer,
-					engine::mixer()->framesPerPeriod() );
+		bool hasInputNoise = m_bufferUsage != NoUsage;
+		bool more = m_effects->processAudioBuffer( m_firstBuffer, engine::mixer()->framesPerPeriod(), hasInputNoise );
 		unlockFirstBuffer();
 		return more;
 	}