diff --git a/examples/fx_chorus/src/bw_example_fx_chorus.c b/examples/fx_chorus/src/bw_example_fx_chorus.c
index 978762b..5347b40 100644
--- a/examples/fx_chorus/src/bw_example_fx_chorus.c
+++ b/examples/fx_chorus/src/bw_example_fx_chorus.c
@@ -37,7 +37,7 @@ BW_SIZE_T bw_example_fx_chorus_mem_req(bw_example_fx_chorus *instance) {
 }
 
 void bw_example_fx_chorus_mem_set(bw_example_fx_chorus *instance, void *mem) {
-	bw_chorus_mem_set(&instance->chorus_state, mem);
+	bw_chorus_mem_set(&instance->chorus_coeffs, &instance->chorus_state, mem);
 }
 
 void bw_example_fx_chorus_reset(bw_example_fx_chorus *instance) {
diff --git a/examples/fx_comb/src/bw_example_fx_comb.c b/examples/fx_comb/src/bw_example_fx_comb.c
index 1f22ca7..431b7f4 100644
--- a/examples/fx_comb/src/bw_example_fx_comb.c
+++ b/examples/fx_comb/src/bw_example_fx_comb.c
@@ -33,7 +33,7 @@ BW_SIZE_T bw_example_fx_comb_mem_req(bw_example_fx_comb *instance) {
 }
 
 void bw_example_fx_comb_mem_set(bw_example_fx_comb *instance, void *mem) {
-	bw_comb_mem_set(&instance->comb_state, mem);
+	bw_comb_mem_set(&instance->comb_coeffs, &instance->comb_state, mem);
 }
 
 void bw_example_fx_comb_reset(bw_example_fx_comb *instance) {
diff --git a/examples/fx_delay/src/bw_example_fx_delay.c b/examples/fx_delay/src/bw_example_fx_delay.c
index e86a79e..5d59278 100644
--- a/examples/fx_delay/src/bw_example_fx_delay.c
+++ b/examples/fx_delay/src/bw_example_fx_delay.c
@@ -33,7 +33,7 @@ BW_SIZE_T bw_example_fx_delay_mem_req(bw_example_fx_delay *instance) {
 }
 
 void bw_example_fx_delay_mem_set(bw_example_fx_delay *instance, void *mem) {
-	bw_delay_mem_set(&instance->delay_state, mem);
+	bw_delay_mem_set(&instance->delay_coeffs, &instance->delay_state, mem);
 }
 
 void bw_example_fx_delay_reset(bw_example_fx_delay *instance) {
diff --git a/examples/fx_flanger/src/bw_example_fx_flanger.c b/examples/fx_flanger/src/bw_example_fx_flanger.c
index 3cccc21..9234955 100644
--- a/examples/fx_flanger/src/bw_example_fx_flanger.c
+++ b/examples/fx_flanger/src/bw_example_fx_flanger.c
@@ -37,7 +37,7 @@ BW_SIZE_T bw_example_fx_flanger_mem_req(bw_example_fx_flanger *instance) {
 }
 
 void bw_example_fx_flanger_mem_set(bw_example_fx_flanger *instance, void *mem) {
-	bw_chorus_mem_set(&instance->chorus_state, mem);
+	bw_chorus_mem_set(&instance->chorus_coeffs, &instance->chorus_state, mem);
 }
 
 void bw_example_fx_flanger_reset(bw_example_fx_flanger *instance) {
diff --git a/examples/fx_reverb/src/bw_example_fx_reverb.c b/examples/fx_reverb/src/bw_example_fx_reverb.c
index f517e94..ae1edc2 100644
--- a/examples/fx_reverb/src/bw_example_fx_reverb.c
+++ b/examples/fx_reverb/src/bw_example_fx_reverb.c
@@ -33,7 +33,7 @@ BW_SIZE_T bw_example_fx_reverb_mem_req(bw_example_fx_reverb *instance) {
 }
 
 void bw_example_fx_reverb_mem_set(bw_example_fx_reverb *instance, void *mem) {
-	bw_reverb_mem_set(&instance->reverb_state, mem);
+	bw_reverb_mem_set(&instance->reverb_coeffs, &instance->reverb_state, mem);
 }
 
 void bw_example_fx_reverb_reset(bw_example_fx_reverb *instance) {
diff --git a/include/bw_chorus.h b/include/bw_chorus.h
index a0d1a8b..85db88b 100644
--- a/include/bw_chorus.h
+++ b/include/bw_chorus.h
@@ -38,6 +38,7 @@
  *    <ul>
  *      <li>Version <strong>0.5.0</strong>:
  *        <ul>
+ *          <li>Updated mem_req/set API.</li>
  *          <li>Now properly setting feedforward delay on reset.</li>
  *        </ul>
  *      </li>
@@ -87,14 +88,14 @@ static inline void bw_chorus_set_sample_rate(bw_chorus_coeffs *BW_RESTRICT coeff
  *
  *    #### bw_chorus_mem_req()
  *  ```>>> */
-static inline BW_SIZE_T bw_chorus_mem_req(bw_chorus_coeffs *BW_RESTRICT coeffs);
+static inline BW_SIZE_T bw_chorus_mem_req(const bw_chorus_coeffs *BW_RESTRICT coeffs);
 /*! <<<```
  *    Returns the size, in bytes, of contiguous memory to be supplied to
  *    `bw_chorus_mem_set()` using `coeffs`.
  *
  *    #### bw_chorus_mem_set()
  *  ```>>> */
-static inline void bw_chorus_mem_set(bw_chorus_state *BW_RESTRICT state, void *mem);
+static inline void bw_chorus_mem_set(const bw_chorus_coeffs *BW_RESTRICT coeffs, bw_chorus_state *BW_RESTRICT state, void *mem);
 /*! <<<```
  *    Associates the contiguous memory block `mem` to the given `state`.
  *
@@ -223,12 +224,13 @@ static inline void bw_chorus_set_sample_rate(bw_chorus_coeffs *BW_RESTRICT coeff
 	bw_comb_set_sample_rate(&coeffs->comb_coeffs, sample_rate);
 }
 
-static inline BW_SIZE_T bw_chorus_mem_req(bw_chorus_coeffs *BW_RESTRICT coeffs) {
+static inline BW_SIZE_T bw_chorus_mem_req(const bw_chorus_coeffs *BW_RESTRICT coeffs) {
 	return bw_comb_mem_req(&coeffs->comb_coeffs);
 }
 
-static inline void bw_chorus_mem_set(bw_chorus_state *BW_RESTRICT state, void *mem) {
-	bw_comb_mem_set(&state->comb_state, mem);
+static inline void bw_chorus_mem_set(const bw_chorus_coeffs *BW_RESTRICT coeffs, bw_chorus_state *BW_RESTRICT state, void *mem) {
+	(void)coeffs;
+	bw_comb_mem_set(&coeffs->comb_coeffs, &state->comb_state, mem);
 }
 
 static inline void bw_chorus_reset_coeffs(bw_chorus_coeffs *BW_RESTRICT coeffs) {
diff --git a/include/bw_comb.h b/include/bw_comb.h
index 17fd3de..b977f38 100644
--- a/include/bw_comb.h
+++ b/include/bw_comb.h
@@ -1,7 +1,7 @@
 /*
  * Brickworks
  *
- * Copyright (C) 2022, 2023 Orastron Srl unipersonale
+ * Copyright (C) 2023 Orastron Srl unipersonale
  *
  * Brickworks is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,7 +20,7 @@
 
 /*!
  *  module_type {{{ dsp }}}
- *  version {{{ 0.4.0 }}}
+ *  version {{{ 0.5.0 }}}
  *  requires {{{
  *    bw_buf bw_common bw_config bw_delay bw_gain bw_math bw_one_pole
  *  }}}
@@ -37,7 +37,14 @@
  *  }}}
  *  changelog {{{
  *    <ul>
+ *      <li>Version <strong>0.5.0</strong>:
+ *        <ul>
+ *          <li>Updated mem_req/set API.</li>
+ *        </ul>
+ *      </li>
+ *    </ul>
  *      <li>Version <strong>0.4.0</strong>:
+ *        <ul>
  *          <li>First release.</li>
  *        </ul>
  *      </li>
@@ -82,14 +89,14 @@ static inline void bw_comb_set_sample_rate(bw_comb_coeffs *BW_RESTRICT coeffs, f
  *
  *    #### bw_comb_mem_req()
  *  ```>>> */
-static inline BW_SIZE_T bw_comb_mem_req(bw_comb_coeffs *BW_RESTRICT coeffs);
+static inline BW_SIZE_T bw_comb_mem_req(const bw_comb_coeffs *BW_RESTRICT coeffs);
 /*! <<<```
  *    Returns the size, in bytes, of contiguous memory to be supplied to
  *    `bw_comb_mem_set()` using `coeffs`.
  *
  *    #### bw_comb_mem_set()
  *  ```>>> */
-static inline void bw_comb_mem_set(bw_comb_state *BW_RESTRICT state, void *mem);
+static inline void bw_comb_mem_set(const bw_comb_coeffs *BW_RESTRICT coeffs, bw_comb_state *BW_RESTRICT state, void *mem);
 /*! <<<```
  *    Associates the contiguous memory block `mem` to the given `state`.
  *
@@ -235,12 +242,13 @@ static inline void bw_comb_set_sample_rate(bw_comb_coeffs *BW_RESTRICT coeffs, f
 	coeffs->fs = sample_rate;
 }
 
-static inline BW_SIZE_T bw_comb_mem_req(bw_comb_coeffs *BW_RESTRICT coeffs) {
+static inline BW_SIZE_T bw_comb_mem_req(const bw_comb_coeffs *BW_RESTRICT coeffs) {
 	return bw_delay_mem_req(&coeffs->delay_coeffs);
 }
 
-static inline void bw_comb_mem_set(bw_comb_state *BW_RESTRICT state, void *mem) {
-	bw_delay_mem_set(&state->delay_state, mem);
+static inline void bw_comb_mem_set(const bw_comb_coeffs *BW_RESTRICT coeffs, bw_comb_state *BW_RESTRICT state, void *mem) {
+	(void)coeffs;
+	bw_delay_mem_set(&coeffs->delay_coeffs, &state->delay_state, mem);
 }
 
 static inline void _bw_comb_do_update_coeffs(bw_comb_coeffs *BW_RESTRICT coeffs, char force) {
diff --git a/include/bw_delay.h b/include/bw_delay.h
index 98ebf05..e2be6ad 100644
--- a/include/bw_delay.h
+++ b/include/bw_delay.h
@@ -20,7 +20,7 @@
 
 /*!
  *  module_type {{{ dsp }}}
- *  version {{{ 0.4.0 }}}
+ *  version {{{ 0.5.0 }}}
  *  requires {{{ bw_buf bw_common bw_config bw_math }}}
  *  description {{{
  *    Interpolated delay line, not smoothed.
@@ -31,6 +31,11 @@
  *  }}}
  *  changelog {{{
  *    <ul>
+ *      <li>Version <strong>0.5.0</strong>:
+ *        <ul>
+ *          <li>Updated mem_req/set API.</li>
+ *        </ul>
+ *      </li>
  *      <li>Version <strong>0.4.0</strong>:
  *        <ul>
  *          <li>First release.</li>
@@ -77,14 +82,14 @@ static inline void bw_delay_set_sample_rate(bw_delay_coeffs *BW_RESTRICT coeffs,
  *
  *    #### bw_delay_mem_req()
  *  ```>>> */
-static inline BW_SIZE_T bw_delay_mem_req(bw_delay_coeffs *BW_RESTRICT coeffs);
+static inline BW_SIZE_T bw_delay_mem_req(const bw_delay_coeffs *BW_RESTRICT coeffs);
 /*! <<<```
  *    Returns the size, in bytes, of contiguous memory to be supplied to
  *    `bw_delay_mem_set()` using `coeffs`.
  *
  *    #### bw_delay_mem_set()
  *  ```>>> */
-static inline void bw_delay_mem_set(bw_delay_state *BW_RESTRICT state, void *mem);
+static inline void bw_delay_mem_set(const bw_delay_coeffs *BW_RESTRICT coeffs, bw_delay_state *BW_RESTRICT state, void *mem);
 /*! <<<```
  *    Associates the contiguous memory block `mem` to the given `state`.
  *
@@ -195,11 +200,12 @@ static inline void bw_delay_set_sample_rate(bw_delay_coeffs *BW_RESTRICT coeffs,
 	coeffs->len = (BW_SIZE_T)bw_ceilf(coeffs->fs * coeffs->max_delay) + 1;
 }
 
-static inline BW_SIZE_T bw_delay_mem_req(bw_delay_coeffs *BW_RESTRICT coeffs) {
+static inline BW_SIZE_T bw_delay_mem_req(const bw_delay_coeffs *BW_RESTRICT coeffs) {
 	return coeffs->len * sizeof(float);
 }
 
-static inline void bw_delay_mem_set(bw_delay_state *BW_RESTRICT state, void *mem) {
+static inline void bw_delay_mem_set(const bw_delay_coeffs *BW_RESTRICT coeffs, bw_delay_state *BW_RESTRICT state, void *mem) {
+	(void)coeffs;
 	state->buf = (float *)mem;
 }
 
diff --git a/include/bw_reverb.h b/include/bw_reverb.h
index 3ef9f6f..b50dc3b 100644
--- a/include/bw_reverb.h
+++ b/include/bw_reverb.h
@@ -80,14 +80,14 @@ static inline void bw_reverb_set_sample_rate(bw_reverb_coeffs *BW_RESTRICT coeff
  *
  *    #### bw_reverb_mem_req()
  *  ```>>> */
-static inline BW_SIZE_T bw_reverb_mem_req(bw_reverb_coeffs *BW_RESTRICT coeffs);
+static inline BW_SIZE_T bw_reverb_mem_req(const bw_reverb_coeffs *BW_RESTRICT coeffs);
 /*! <<<```
  *    Returns the size, in bytes, of contiguous memory to be supplied to
  *    `bw_reverb_mem_set()` using `coeffs`.
  *
  *    #### bw_reverb_mem_set()
  *  ```>>> */
-static inline void bw_reverb_mem_set(bw_reverb_state *BW_RESTRICT state, void *mem);
+static inline void bw_reverb_mem_set(const bw_reverb_coeffs *BW_RESTRICT coeffs, bw_reverb_state *BW_RESTRICT state, void *mem);
 /*! <<<```
  *    Associates the contiguous memory block `mem` to the given `state`.
  *
@@ -227,6 +227,18 @@ struct _bw_reverb_coeffs {
 struct _bw_reverb_state {
 	bw_delay_state		predelay_state;
 	bw_lp1_state		bandwidth_state;
+	bw_delay_state		delay_id1_state;
+	bw_delay_state		delay_id2_state;
+	bw_delay_state		delay_id3_state;
+	bw_delay_state		delay_id4_state;
+	bw_delay_state		delay_dd1_state;
+	bw_delay_state		delay_dd2_state;
+	bw_delay_state		delay_dd3_state;
+	bw_delay_state		delay_dd4_state;
+	bw_delay_state		delay_d1_state;
+	bw_delay_state		delay_d2_state;
+	bw_delay_state		delay_d3_state;
+	bw_delay_state		delay_d4_state;
 };
 
 static inline void bw_reverb_init(bw_reverb_coeffs *BW_RESTRICT coeffs) {
@@ -285,10 +297,9 @@ static inline void bw_reverb_set_sample_rate(bw_reverb_coeffs *BW_RESTRICT coeff
 	coeffs->d2 = (BW_SIZE_T)bw_roundf(coeffs->fs * (3720.f / 29761.f));
 	coeffs->d3 = (BW_SIZE_T)bw_roundf(coeffs->fs * (4217.f / 29761.f));
 	coeffs->d4 = (BW_SIZE_T)bw_roundf(coeffs->fs * (3163.f / 29761.f));
-	//set delay...
 }
 
-static inline BW_SIZE_T bw_reverb_mem_req(bw_reverb_coeffs *BW_RESTRICT coeffs) {
+static inline BW_SIZE_T bw_reverb_mem_req(const bw_reverb_coeffs *BW_RESTRICT coeffs) {
 	return bw_delay_mem_req(&coeffs->predelay_coeffs)
 		+ bw_delay_mem_req(&coeffs->delay_id1_coeffs)
 		+ bw_delay_mem_req(&coeffs->delay_id2_coeffs)
@@ -304,32 +315,33 @@ static inline BW_SIZE_T bw_reverb_mem_req(bw_reverb_coeffs *BW_RESTRICT coeffs)
 		+ bw_delay_mem_req(&coeffs->delay_d4_coeffs);
 }
 
-static inline void bw_reverb_mem_set(bw_reverb_state *BW_RESTRICT state, void *mem) {
-	bw_delay_mem_set(&state->predelay_state, mem);
-	mem += bw_delay_mem_req(&coeffs->predelay_coeffs) * sizeof(float);
-	bw_delay_mem_set(&state->delay_id1_state, mem);
-	mem += bw_delay_mem_req(&coeffs->delay_id1_coeffs) * sizeof(float);
-	bw_delay_mem_set(&state->delay_id2_state, mem);
-	mem += bw_delay_mem_req(&coeffs->delay_id2_coeffs) * sizeof(float);
-	bw_delay_mem_set(&state->delay_id3_state, mem);
-	mem += bw_delay_mem_req(&coeffs->delay_id3_coeffs) * sizeof(float);
-	bw_delay_mem_set(&state->delay_id4_state, mem);
-	mem += bw_delay_mem_req(&coeffs->delay_id4_coeffs) * sizeof(float);
-	bw_delay_mem_set(&state->delay_dd1_state, mem);
-	mem += bw_delay_mem_req(&coeffs->delay_dd1_coeffs) * sizeof(float);
-	bw_delay_mem_set(&state->delay_dd2_state, mem);
-	mem += bw_delay_mem_req(&coeffs->delay_dd2_coeffs) * sizeof(float);
-	bw_delay_mem_set(&state->delay_dd3_state, mem);
-	mem += bw_delay_mem_req(&coeffs->delay_dd3_coeffs) * sizeof(float);
-	bw_delay_mem_set(&state->delay_dd4_state, mem);
-	mem += bw_delay_mem_req(&coeffs->delay_dd4_coeffs) * sizeof(float);
-	bw_delay_mem_set(&state->delay_d1_state, mem);
-	mem += bw_delay_mem_req(&coeffs->delay_d1_coeffs) * sizeof(float);
-	bw_delay_mem_set(&state->delay_d2_state, mem);
-	mem += bw_delay_mem_req(&coeffs->delay_d2_coeffs) * sizeof(float);
-	bw_delay_mem_set(&state->delay_d3_state, mem);
-	mem += bw_delay_mem_req(&coeffs->delay_d3_coeffs) * sizeof(float);
-	bw_delay_mem_set(&state->delay_d4_state, mem);
+static inline void bw_reverb_mem_set(const bw_reverb_coeffs *BW_RESTRICT coeffs, bw_reverb_state *BW_RESTRICT state, void *mem) {
+	float *m = (float *)mem;
+	bw_delay_mem_set(&coeffs->predelay_coeffs, &state->predelay_state, m);
+	m += bw_delay_mem_req(&coeffs->predelay_coeffs);
+	bw_delay_mem_set(&coeffs->delay_id1_coeffs, &state->delay_id1_state, m);
+	m += bw_delay_mem_req(&coeffs->delay_id1_coeffs);
+	bw_delay_mem_set(&coeffs->delay_id2_coeffs, &state->delay_id2_state, m);
+	m += bw_delay_mem_req(&coeffs->delay_id2_coeffs);
+	bw_delay_mem_set(&coeffs->delay_id3_coeffs, &state->delay_id3_state, m);
+	m += bw_delay_mem_req(&coeffs->delay_id3_coeffs);
+	bw_delay_mem_set(&coeffs->delay_id4_coeffs, &state->delay_id4_state, m);
+	m += bw_delay_mem_req(&coeffs->delay_id4_coeffs);
+	bw_delay_mem_set(&coeffs->delay_dd1_coeffs, &state->delay_dd1_state, m);
+	m += bw_delay_mem_req(&coeffs->delay_dd1_coeffs);
+	bw_delay_mem_set(&coeffs->delay_dd2_coeffs, &state->delay_dd2_state, m);
+	m += bw_delay_mem_req(&coeffs->delay_dd2_coeffs);
+	bw_delay_mem_set(&coeffs->delay_dd3_coeffs, &state->delay_dd3_state, m);
+	m += bw_delay_mem_req(&coeffs->delay_dd3_coeffs);
+	bw_delay_mem_set(&coeffs->delay_dd4_coeffs, &state->delay_dd4_state, m);
+	m += bw_delay_mem_req(&coeffs->delay_dd4_coeffs);
+	bw_delay_mem_set(&coeffs->delay_d1_coeffs, &state->delay_d1_state, m);
+	m += bw_delay_mem_req(&coeffs->delay_d1_coeffs);
+	bw_delay_mem_set(&coeffs->delay_d2_coeffs, &state->delay_d2_state, m);
+	m += bw_delay_mem_req(&coeffs->delay_d2_coeffs);
+	bw_delay_mem_set(&coeffs->delay_d3_coeffs, &state->delay_d3_state, m);
+	m += bw_delay_mem_req(&coeffs->delay_d3_coeffs);
+	bw_delay_mem_set(&coeffs->delay_d4_coeffs, &state->delay_d4_state, m);
 }
 
 static inline void bw_reverb_reset_coeffs(bw_reverb_coeffs *BW_RESTRICT coeffs) {
@@ -382,16 +394,19 @@ static inline void bw_reverb_update_coeffs_audio(bw_reverb_coeffs *BW_RESTRICT c
 	bw_delay_set_delay(&coeffs->predelay_coeffs, pd);
 	bw_delay_update_coeffs_ctrl(&coeffs->predelay_coeffs);
 	bw_delay_update_coeffs_audio(&coeffs->predelay_coeffs);
-	//...
 }
 
 static inline void bw_reverb_process1(const bw_reverb_coeffs *BW_RESTRICT coeffs, bw_reverb_state *BW_RESTRICT state, float xl, float xr, float *yl, float *yr) {
 	const float i = 0.5f * (xl + xr);
 	const float pd = bw_delay_process1(&coeffs->predelay_coeffs, &state->predelay_state, i);
 	const float bw = bw_lp1_process1(&coeffs->bandwidth_coeffs, &state->bandwidth_state, pd);
+	const float n14 = bw_delay_read(&coeffs->delay_id1_coeffs, &state->delay_id1_state, coeffs->id1, 0.f);
+	const float n13 = bw - 0.75f * n14;
+	const float id1 = 0.75f * n13 + n14;
+	bw_delay_write(&coeffs->delay_id1_coeffs, &state->delay_id1_state, n13);
 	//...
-	*yl = bw_drywet_process1(&coeffs->drywet_coeffs, xl, bw);
-	*yr = bw_drywet_process1(&coeffs->drywet_coeffs, xr, bw);
+	*yl = bw_drywet_process1(&coeffs->drywet_coeffs, xl, id1);
+	*yr = bw_drywet_process1(&coeffs->drywet_coeffs, xr, id1);
 }
 
 static inline void bw_reverb_process(bw_reverb_coeffs *BW_RESTRICT coeffs, bw_reverb_state *BW_RESTRICT state, const float *xl, const float *xr, float *yl, float *yr, int n_samples) {