diff --git a/Appli/Core/Inc/fx_octaver.h b/Appli/Core/Inc/fx_octaver.h
index 48a5463..3adacaa 100644
--- a/Appli/Core/Inc/fx_octaver.h
+++ b/Appli/Core/Inc/fx_octaver.h
@@ -8,8 +8,12 @@
 extern "C" {
 #endif
 
-#define FX_OCTAVER_BUFFER_SIZE  2048U   /* buffer circulaire (puissance de 2) */
-#define FX_OCTAVER_GRAIN_SIZE   1024U   /* taille de grain, en echantillons (~21ms a 48kHz) */
+#define FX_OCTAVER_BUFFER_SIZE  4096U   /* buffer circulaire (puissance de 2) */
+#define FX_OCTAVER_GRAIN_SIZE   2048U   /* taille de grain, en echantillons (~43ms a 48kHz) :
+                                          * doit largement couvrir la periode des notes les plus
+                                          * graves jouees (ex. do2 ~65Hz, periode ~734 echantillons
+                                          * a 48kHz) pour limiter les artefacts de phase entre les
+                                          * deux grains en fondu croise. */
 #define FX_OCTAVER_NUM_VOICES   4U      /* -2oct, -1oct, +1oct, +2oct (la voie seche est geree a part) */
 
 typedef struct
diff --git a/Appli/Core/Src/fx_equalizer.c b/Appli/Core/Src/fx_equalizer.c
index 18c7b27..c3754f0 100644
--- a/Appli/Core/Src/fx_equalizer.c
+++ b/Appli/Core/Src/fx_equalizer.c
@@ -11,7 +11,7 @@ static const float fx_eq_default_freqs[FX_EQ_NUM_BANDS] =
 
 void FxEqualizer_Init(FxEqualizerState *state, FxEqualizerParams *params)
 {
-    params->enabled = false;
+    params->enabled = true;
     for (uint32_t i = 0; i < FX_EQ_NUM_BANDS; i++)
     {
         params->bands[i].freq_hz = fx_eq_default_freqs[i];
@@ -23,6 +23,11 @@ void FxEqualizer_Init(FxEqualizerState *state, FxEqualizerParams *params)
         state->band_state[i].last_q       = 0.0f;
         state->x1[i] = state->x2[i] = state->y1[i] = state->y2[i] = 0.0f;
     }
+
+    // Pour couper les basses par defaukt et éviter les larsens : 
+    params->bands[0].gain_db = -15.0f;
+    params->bands[1].gain_db = -10.0f;
+    params->bands[2].gain_db = -2.5f;
 }
 
 /* Filtre "peaking EQ" (cloche), formule de l'Audio EQ Cookbook (Robert Bristow-Johnson). */
diff --git a/Appli/Core/Src/fx_octaver.c b/Appli/Core/Src/fx_octaver.c
index fc47980..06c1a3c 100644
--- a/Appli/Core/Src/fx_octaver.c
+++ b/Appli/Core/Src/fx_octaver.c
@@ -47,7 +47,13 @@ static inline float FxOctaver_EnvLookup(float phase)
 
 static inline float FxOctaver_ReadInterpolated(const float *buffer, uint32_t write_idx, float delay)
 {
-    float read_pos = (float)write_idx - delay;
+    /* write_idx grandit sans jamais etre replie (compteur perpetuel) ; le convertir
+     * directement en float finirait par perdre en precision (un float ne represente
+     * exactement les entiers que jusqu'a ~16.7 millions, soit quelques minutes a
+     * 48kHz). On calcule donc la position de lecture uniquement a partir de l'index
+     * DEJA REPLIE dans le buffer, qui reste toujours petit. */
+    float write_pos = (float)(write_idx & FX_OCTAVER_BUFFER_MASK);
+    float read_pos = write_pos - delay;
     while (read_pos < 0.0f)
     {
         read_pos += (float)FX_OCTAVER_BUFFER_SIZE;
diff --git a/Appli/TouchGFX/CelloEffects.touchgfx b/Appli/TouchGFX/CelloEffects.touchgfx
index 63d9fe3..09148b8 100644
--- a/Appli/TouchGFX/CelloEffects.touchgfx
+++ b/Appli/TouchGFX/CelloEffects.touchgfx
@@ -835,7 +835,7 @@
             "InteractionName": "Interaction7",
             "Trigger": {
               "Type": "TriggerSliderValueChanged",
-              "TriggerComponent": "slider4"
+              "TriggerComponent": "slider5"
             },
             "Action": {
               "Type": "ActionCustom",