diff --git a/Makefile b/Makefile
index 53a0ef65..2d26aedb 100644
--- a/Makefile
+++ b/Makefile
@@ -131,6 +131,7 @@ $(BUILD_DIR)/src/musyx/dsp_import.o: CFLAGS := $(CFLAGS_MUSYX)
 $(BUILD_DIR)/src/musyx/hw_memory.o: CFLAGS := $(CFLAGS_MUSYX)
 $(BUILD_DIR)/src/musyx/reverb_fx.o: CFLAGS := $(CFLAGS_MUSYX)
 $(BUILD_DIR)/src/musyx/delay_fx.o: CFLAGS := $(CFLAGS_MUSYX)
+$(BUILD_DIR)/src/musyx/creverb_fx.o: CFLAGS := $(CFLAGS_MUSYX)
 
 
 #-------------------------------------------------------------------------------
diff --git a/include/musyx/musyx.h b/include/musyx/musyx.h
index 0f64e5cb..425bfa2d 100644
--- a/include/musyx/musyx.h
+++ b/include/musyx/musyx.h
@@ -77,8 +77,8 @@ typedef struct SND_AUX_REVERBHI {
 } SND_AUX_REVERBHI;
 
 void sndAuxCallbackReverbHI(u8 reason, SND_AUX_INFO* info, void* user);
-bool8 sndAuxCallbackPrepareReverbHI(SND_AUX_REVERBHI *rev);
-bool8 sndAuxCallbackShutdownReverbHI(SND_AUX_REVERBHI* rev);
+s32 sndAuxCallbackPrepareReverbHI(SND_AUX_REVERBHI* rev);
+s32 sndAuxCallbackShutdownReverbHI(SND_AUX_REVERBHI* rev);
 
 typedef struct SND_AUX_DELAY {
   u32 currentSize[3];
@@ -95,12 +95,48 @@ typedef struct SND_AUX_DELAY {
   u32 output[3];   // Output volume in % per channel
 } SND_AUX_DELAY;
 
+void sndAuxCallbackDelay(u8 reason, SND_AUX_INFO* info, void* user);
+s32 sndAuxCallbackUpdateSettingsDelay(SND_AUX_DELAY* delay);
+s32 sndAuxCallbackPrepareDelay(SND_AUX_DELAY* rev);
+s32 sndAuxCallbackShutdownDelay(SND_AUX_DELAY* rev);
+s32 sndAuxCallbackUpdateSettingsReverbHI(SND_AUX_REVERBHI *rev);
 
-void sndAuxCallbackDelay(u8 reason,SND_AUX_INFO *info, void *user);
-bool8 sndAuxCallbackUpdateSettingsDelay(SND_AUX_DELAY *delay);
-bool8 sndAuxCallbackPrepareDelay(SND_AUX_DELAY *rev);
-bool8 sndAuxCallbackShutdownDelay(SND_AUX_DELAY* rev);
+typedef struct _SND_REVSTD_DELAYLINE {
+  s32 inPoint;
+  s32 outPoint;
+  s32 length;
+  f32* inputs;
+  f32 lastOutput;
+} _SND_REVSTD_DELAYLINE;
 
+typedef struct _SND_REVSTD_WORK {
+  _SND_REVSTD_DELAYLINE AP[6];
+  _SND_REVSTD_DELAYLINE C[6];
+  f32 allPassCoeff;
+  f32 combCoef[6];
+  f32 lpLastout[3];
+  f32 level;
+  f32 damping;
+  s32 preDelayTime;
+  f32* preDelayLine[3];
+  f32* preDelayPtr[3];
+} _SND_REVSTD_WORK;
+
+typedef struct SND_AUX_REVERBSTD {
+  _SND_REVSTD_WORK rv;
+  bool8 tempDisableFX;
+
+  f32 coloration;
+  f32 mix;
+  f32 time;
+  f32 damping;
+  f32 preDelay;
+} SND_AUX_REVERBSTD;
+
+void sndAuxCallbackReverbSTD(u8 reason,SND_AUX_INFO *info,void *user);
+s32 sndAuxCallbackPrepareReverbSTD(SND_AUX_REVERBSTD *rev);
+s32 sndAuxCallbackShutdownReverbSTD(SND_AUX_REVERBSTD *rev);
+s32 sndAuxCallbackUpdateSettingsReverbSTD(SND_AUX_REVERBSTD *rev);
 #ifdef __cplusplus
 }
 #endif
diff --git a/obj_files.mk b/obj_files.mk
index fa4bb3ea..c3b624ca 100644
--- a/obj_files.mk
+++ b/obj_files.mk
@@ -806,7 +806,7 @@ MUSYX_FILES :=\
 	$(BUILD_DIR)/src/musyx/dsp_import.o\
 	$(BUILD_DIR)/asm/musyx/hw_dolphin.o\
 	$(BUILD_DIR)/src/musyx/hw_memory.o\
-	$(BUILD_DIR)/asm/musyx/creverb_fx.o\
+	$(BUILD_DIR)/src/musyx/creverb_fx.o\
 	$(BUILD_DIR)/asm/musyx/creverb.o\
 	$(BUILD_DIR)/src/musyx/reverb_fx.o\
 	$(BUILD_DIR)/asm/musyx/reverb.o\
diff --git a/src/musyx/creverb_fx.c b/src/musyx/creverb_fx.c
new file mode 100644
index 00000000..8af09242
--- /dev/null
+++ b/src/musyx/creverb_fx.c
@@ -0,0 +1,34 @@
+#include "musyx/musyx_priv.h"
+
+extern s32 ReverbSTDCreate(_SND_REVSTD_WORK* rv, f32 coloration, f32 time, f32 mix, f32 damping, f32 preDelay);
+extern void ReverbHIFree(_SND_REVSTD_WORK* rev);
+extern void ReverbSTDCallback(s32* left, s32* right, s32* surround, _SND_REVSTD_WORK* rv);
+
+void sndAuxCallbackReverbSTD(u8 reason, SND_AUX_INFO* info, void* user) {
+  SND_AUX_REVERBSTD* rev ;
+  switch (reason) {
+  case SND_AUX_REASON_BUFFERUPDATE:
+    rev = (SND_AUX_REVERBSTD*)user;
+    if ((u8)rev->tempDisableFX == 0) {
+      ReverbSTDCallback(info->data.bufferUpdate.left, info->data.bufferUpdate.right, info->data.bufferUpdate.surround,
+                        &rev->rv);
+    }
+  case SND_AUX_REASON_PARAMETERUPDATE:
+    break;
+  default:
+    // ASSERT_MSG(FALSE);
+    break;
+  }
+}
+
+s32 sndAuxCallbackPrepareReverbSTD(SND_AUX_REVERBSTD* rev) {
+  rev->tempDisableFX = 0;
+  return ReverbSTDCreate(&rev->rv, rev->coloration, rev->time, rev->mix, rev->damping, rev->preDelay);
+}
+s32 sndAuxCallbackShutdownReverbSTD(SND_AUX_REVERBSTD* rev) {
+  ReverbSTDFree(&rev->rv);
+  return 1;
+}
+
+s32 sndAuxCallbackUpdateSettingsReverbSTD(SND_AUX_REVERBSTD* rev) { /* not in MP */
+}
diff --git a/src/musyx/delay_fx.c b/src/musyx/delay_fx.c
index 23d3ddac..25e26f31 100644
--- a/src/musyx/delay_fx.c
+++ b/src/musyx/delay_fx.c
@@ -24,7 +24,7 @@ void sndAuxCallbackDelay(u8 reason, SND_AUX_INFO* info, void* user) {
   s32* surPtr;
   SND_AUX_DELAY* delay;
   switch (reason) {
-  case 0:
+  case SND_AUX_REASON_BUFFERUPDATE:
     delay = (SND_AUX_DELAY*)user;
     leftOffset = delay->left + (delay->currentPos[0] * 160);
     leftPtr = info->data.bufferUpdate.left;
@@ -52,14 +52,14 @@ void sndAuxCallbackDelay(u8 reason, SND_AUX_INFO* info, void* user) {
     delay->currentPos[0] = (delay->currentPos[0] + 1) % delay->currentSize[0];
     delay->currentPos[1] = (delay->currentPos[1] + 1) % delay->currentSize[1];
     delay->currentPos[2] = (delay->currentPos[2] + 1) % delay->currentSize[2];
-  case 1: break;
+  case SND_AUX_REASON_PARAMETERUPDATE: break;
   default:
     // ASSERT_MSG(FALSE);
     break;
   }
 }
 
-bool8 sndAuxCallbackUpdateSettingsDelay(SND_AUX_DELAY* delay) {
+s32 sndAuxCallbackUpdateSettingsDelay(SND_AUX_DELAY* delay) {
   s32 i;
   s32* left;
   s32* right;
@@ -99,12 +99,12 @@ bool8 sndAuxCallbackUpdateSettingsDelay(SND_AUX_DELAY* delay) {
   return 1;
 }
 
-bool8 sndAuxCallbackPrepareDelay(SND_AUX_DELAY* delay) {
+s32 sndAuxCallbackPrepareDelay(SND_AUX_DELAY* delay) {
   delay->left = NULL;
   return sndAuxCallbackUpdateSettingsDelay(delay);
 }
 
-bool8 sndAuxCallbackShutdownDelay(SND_AUX_DELAY* delay) {
+s32 sndAuxCallbackShutdownDelay(SND_AUX_DELAY* delay) {
   if (delay->left != NULL) {
     salFree(delay->left);
     salFree(delay->right);
diff --git a/src/musyx/reverb_fx.c b/src/musyx/reverb_fx.c
index 38f51cdb..6d49def6 100644
--- a/src/musyx/reverb_fx.c
+++ b/src/musyx/reverb_fx.c
@@ -17,7 +17,7 @@
   
 
 
-extern bool8 ReverbHICreate(_SND_REVHI_WORK* rev, f32 coloration, f32 time, f32 mix, f32 damping, f32 preDelay, f32 crosstalk);
+extern s32 ReverbHICreate(_SND_REVHI_WORK* rev, f32 coloration, f32 time, f32 mix, f32 damping, f32 preDelay, f32 crosstalk);
 extern void ReverbHIFree(_SND_REVHI_WORK* rev);
 
 void sndAuxCallbackReverbHI(u8 reason, SND_AUX_INFO* info, void* user) {
@@ -36,12 +36,16 @@ void sndAuxCallbackReverbHI(u8 reason, SND_AUX_INFO* info, void* user) {
     }
 }
 
-bool8 sndAuxCallbackPrepareReverbHI(SND_AUX_REVERBHI *rev) {
+s32 sndAuxCallbackPrepareReverbHI(SND_AUX_REVERBHI *rev) {
     rev->tempDisableFX = 0;
     return ReverbHICreate(&rev->rv, rev->coloration, rev->time, rev->mix, rev->damping, rev->preDelay, rev->crosstalk);
 }
 
-bool8 sndAuxCallbackShutdownReverbHI(SND_AUX_REVERBHI* rev) {
+s32 sndAuxCallbackShutdownReverbHI(SND_AUX_REVERBHI* rev) {
     ReverbHIFree(&rev->rv);
     return 1;
 }
+
+s32 sndAuxCallbackUpdateSettingsReverbHI(SND_AUX_REVERBHI *rev) {
+    /* not in MP */
+}