diff --git a/include/bw_cab.h b/include/bw_cab.h
index 2fd615f..9eb95a5 100644
--- a/include/bw_cab.h
+++ b/include/bw_cab.h
@@ -33,7 +33,7 @@
  *      <li>Version <strong>1.0.1</strong>:
  *        <ul>
  *          <li>Added debugging checks from <code>bw_cab_process()</code> to
- *              <code>bw_cab_process_multi()</code>.
+ *              <code>bw_cab_process_multi()</code>.</li>
  *          <li>Added debugging checks in <code>bw_cab_process_multi()</code> to
  *              ensure that buffers used for both input and output appear at the
  *              same channel indices.</li>
diff --git a/include/bw_chorus.h b/include/bw_chorus.h
index ada423a..73aab76 100644
--- a/include/bw_chorus.h
+++ b/include/bw_chorus.h
@@ -39,7 +39,7 @@
  *      <li>Version <strong>1.1.1</strong>:
  *        <ul>
  *          <li>Added debugging checks from <code>bw_chorus_process()</code> to
- *              <code>bw_chorus_process_multi()</code>.
+ *              <code>bw_chorus_process_multi()</code>.</li>
  *          <li>Added debugging checks in <code>bw_chorus_process_multi()</code>
  *              to ensure that buffers used for both input and output appear at
  *              the same channel indices.</li>
diff --git a/include/bw_clip.h b/include/bw_clip.h
index 537e5cb..b1130ab 100644
--- a/include/bw_clip.h
+++ b/include/bw_clip.h
@@ -48,7 +48,7 @@
  *      <li>Version <strong>1.1.1</strong>:
  *        <ul>
  *          <li>Added debugging checks from <code>bw_clip_process()</code> to
- *              <code>bw_clip_process_multi()</code>.
+ *              <code>bw_clip_process_multi()</code>.</li>
  *          <li>Added debugging checks in <code>bw_clip_process_multi()</code>
  *              to ensure that buffers used for both input and output appear at
  *              the same channel indices.</li>
diff --git a/include/bw_comb.h b/include/bw_comb.h
index 1352ef5..df2b4f6 100644
--- a/include/bw_comb.h
+++ b/include/bw_comb.h
@@ -40,7 +40,7 @@
  *      <li>Version <strong>1.1.1</strong>:
  *        <ul>
  *          <li>Added debugging checks from <code>bw_comb_process()</code> to
- *              <code>bw_comb_process_multi()</code>.
+ *              <code>bw_comb_process_multi()</code>.</li>
  *          <li>Added debugging checks in <code>bw_comb_process_multi()</code>
  *              to ensure that buffers used for both input and output appear at
  *              the same channel indices.</li>
diff --git a/include/bw_comp.h b/include/bw_comp.h
index 6dd44d1..853b3e7 100644
--- a/include/bw_comp.h
+++ b/include/bw_comp.h
@@ -32,7 +32,7 @@
  *      <li>Version <strong>1.1.1</strong>:
  *        <ul>
  *          <li>Added debugging checks from <code>bw_comp_process()</code> to
- *              <code>bw_comp_process_multi()</code>.
+ *              <code>bw_comp_process_multi()</code>.</li>
  *          <li>Added debugging checks in <code>bw_comp_process_multi()</code>
  *              to ensure that buffers used for both input and output appear at
  *              the same channel indices.</li>
diff --git a/include/bw_delay.h b/include/bw_delay.h
index 106b558..72aed68 100644
--- a/include/bw_delay.h
+++ b/include/bw_delay.h
@@ -34,7 +34,7 @@
  *      <li>Version <strong>1.1.1</strong>:
  *        <ul>
  *          <li>Added debugging checks from <code>bw_delay_process()</code> to
- *              <code>bw_delay_process_multi()</code>.
+ *              <code>bw_delay_process_multi()</code>.</li>
  *          <li>Added debugging checks in <code>bw_delay_process_multi()</code>
  *              to ensure that buffers used for both input and output appear at
  *              the same channel indices.</li>
diff --git a/include/bw_dist.h b/include/bw_dist.h
index 9086885..dece4ac 100644
--- a/include/bw_dist.h
+++ b/include/bw_dist.h
@@ -34,6 +34,8 @@
  *    <ul>
  *      <li>Version <strong>1.1.1</strong>:
  *        <ul>
+ *          <li>Added debugging checks from <code>bw_dist_process()</code> to
+ *              <code>bw_dist_process_multi()</code>.</li>
  *          <li>Added debugging checks in <code>bw_dist_process_multi()</code>
  *              to ensure that buffers used for both input and output appear at
  *              the same channel indices.</li>
@@ -555,6 +557,10 @@ static inline void bw_dist_process_multi(
 	BW_ASSERT_DEEP(coeffs->state >= bw_dist_coeffs_state_reset_coeffs);
 	BW_ASSERT(state != BW_NULL);
 #ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT(state[i] != BW_NULL);
+		BW_ASSERT_DEEP(bw_dist_state_is_valid(coeffs, state[i]));
+	}
 	for (size_t i = 0; i < n_channels; i++)
 		for (size_t j = i + 1; j < n_channels; j++)
 			BW_ASSERT(state[i] != state[j]);
@@ -562,6 +568,11 @@ static inline void bw_dist_process_multi(
 	BW_ASSERT(x != BW_NULL);
 	BW_ASSERT(y != BW_NULL);
 #ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT(x[i] != BW_NULL);
+		BW_ASSERT_DEEP(bw_has_only_finite(x[i], n_samples));
+		BW_ASSERT(y[i] != BW_NULL);
+	}
 	for (size_t i = 0; i < n_channels; i++)
 		for (size_t j = i + 1; j < n_channels; j++)
 			BW_ASSERT(y[i] != y[j]);
@@ -579,6 +590,12 @@ static inline void bw_dist_process_multi(
 
 	BW_ASSERT_DEEP(bw_dist_coeffs_is_valid(coeffs));
 	BW_ASSERT_DEEP(coeffs->state >= bw_dist_coeffs_state_reset_coeffs);
+#ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT_DEEP(bw_dist_state_is_valid(coeffs, state[i]));
+		BW_ASSERT_DEEP(bw_has_only_finite(y[i], n_samples));
+	}
+#endif
 }
 
 static inline void bw_dist_set_distortion(
diff --git a/include/bw_drive.h b/include/bw_drive.h
index 50ac11f..df18264 100644
--- a/include/bw_drive.h
+++ b/include/bw_drive.h
@@ -34,6 +34,8 @@
  *    <ul>
  *      <li>Version <strong>1.1.1</strong>:
  *        <ul>
+ *          <li>Added debugging checks from <code>bw_drive_process()</code> to
+ *              <code>bw_drive_process_multi()</code>.</li>
  *          <li>Added debugging checks in <code>bw_drive_process_multi()</code>
  *              to ensure that buffers used for both input and output appear at
  *              the same channel indices.</li>
@@ -558,6 +560,10 @@ static inline void bw_drive_process_multi(
 	BW_ASSERT_DEEP(coeffs->state >= bw_drive_coeffs_state_reset_coeffs);
 	BW_ASSERT(state != BW_NULL);
 #ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT(state[i] != BW_NULL);
+		BW_ASSERT_DEEP(bw_drive_state_is_valid(coeffs, state[i]));
+	}
 	for (size_t i = 0; i < n_channels; i++)
 		for (size_t j = i + 1; j < n_channels; j++)
 			BW_ASSERT(state[i] != state[j]);
@@ -565,6 +571,11 @@ static inline void bw_drive_process_multi(
 	BW_ASSERT(x != BW_NULL);
 	BW_ASSERT(y != BW_NULL);
 #ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT(x[i] != BW_NULL);
+		BW_ASSERT_DEEP(bw_has_only_finite(x[i], n_samples));
+		BW_ASSERT(y[i] != BW_NULL);
+	}
 	for (size_t i = 0; i < n_channels; i++)
 		for (size_t j = i + 1; j < n_channels; j++)
 			BW_ASSERT(y[i] != y[j]);
@@ -582,6 +593,12 @@ static inline void bw_drive_process_multi(
 
 	BW_ASSERT_DEEP(bw_drive_coeffs_is_valid(coeffs));
 	BW_ASSERT_DEEP(coeffs->state >= bw_drive_coeffs_state_reset_coeffs);
+#ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT_DEEP(bw_drive_state_is_valid(coeffs, state[i]));
+		BW_ASSERT_DEEP(bw_has_only_finite(y[i], n_samples));
+	}
+#endif
 }
 
 static inline void bw_drive_set_drive(
diff --git a/include/bw_dry_wet.h b/include/bw_dry_wet.h
index fd16edf..2c3fc0d 100644
--- a/include/bw_dry_wet.h
+++ b/include/bw_dry_wet.h
@@ -29,6 +29,8 @@
  *    <ul>
  *      <li>Version <strong>1.2.0</strong>:
  *        <ul>
+ *          <li>Added debugging checks from <code>bw_dry_wet_process()</code> to
+ *              <code>bw_dry_wet_process_multi()</code>.</li>
  *          <li>Added <code>bw_dry_wet_get_wet()</code> and
  *              <code>bw_dry_wet_get_wet_cur()</code>, and corresponding C++
  *              API.</li>
@@ -380,6 +382,13 @@ static inline void bw_dry_wet_process_multi(
 	BW_ASSERT(x_wet != BW_NULL);
 	BW_ASSERT(y != BW_NULL);
 #ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT(x_dry[i] != BW_NULL);
+		BW_ASSERT_DEEP(bw_has_only_finite(x_dry[i], n_samples));
+		BW_ASSERT(x_wet[i] != BW_NULL);
+		BW_ASSERT_DEEP(bw_has_only_finite(x_wet[i], n_samples));
+		BW_ASSERT(y[i] != BW_NULL);
+	}
 	for (size_t i = 0; i < n_channels; i++)
 		for (size_t j = i + 1; j < n_channels; j++)
 			BW_ASSERT(y[i] != y[j]);
@@ -399,6 +408,10 @@ static inline void bw_dry_wet_process_multi(
 
 	BW_ASSERT_DEEP(bw_dry_wet_coeffs_is_valid(coeffs));
 	BW_ASSERT_DEEP(coeffs->state >= bw_dry_wet_coeffs_state_reset_coeffs);
+#ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++)
+		BW_ASSERT_DEEP(bw_has_only_finite(y[i], n_samples));
+#endif
 }
 
 static inline void bw_dry_wet_set_wet(
diff --git a/include/bw_env_follow.h b/include/bw_env_follow.h
index fbbc737..3fba7b5 100644
--- a/include/bw_env_follow.h
+++ b/include/bw_env_follow.h
@@ -30,6 +30,8 @@
  *    <ul>
  *      <li>Version <strong>1.1.1</strong>:
  *        <ul>
+ *          <li>Added debugging checks from <code>bw_env_follow_process()</code>
+ *              to <code>bw_env_follow_process_multi()</code>.</li>
  *          <li>Added debugging checks in
  *              <code>bw_env_follow_process_multi()</code> to ensure that
  *              buffers used for both input and output appear at the same
@@ -523,12 +525,20 @@ static inline void bw_env_follow_process_multi(
 	BW_ASSERT_DEEP(coeffs->state >= bw_env_follow_coeffs_state_reset_coeffs);
 	BW_ASSERT(state != BW_NULL);
 #ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT(state[i] != BW_NULL);
+		BW_ASSERT_DEEP(bw_env_follow_state_is_valid(coeffs, state[i]));
+	}
 	for (size_t i = 0; i < n_channels; i++)
 		for (size_t j = i + 1; j < n_channels; j++)
 			BW_ASSERT(state[i] != state[j]);
 #endif
 	BW_ASSERT(x != BW_NULL);
 #ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT(x[i] != BW_NULL);
+		BW_ASSERT_DEEP(bw_has_only_finite(x[i], n_samples));
+	}
 	if (y != BW_NULL) {
 		for (size_t i = 0; i < n_channels; i++)
 			for (size_t j = i + 1; j < n_channels; j++)
@@ -558,6 +568,12 @@ static inline void bw_env_follow_process_multi(
 
 	BW_ASSERT_DEEP(bw_env_follow_coeffs_is_valid(coeffs));
 	BW_ASSERT_DEEP(coeffs->state >= bw_env_follow_coeffs_state_reset_coeffs);
+#ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT_DEEP(bw_env_follow_state_is_valid(coeffs, state[i]));
+		BW_ASSERT_DEEP(y != BW_NULL && y[i] != BW_NULL ? bw_has_only_finite(y[i], n_samples) : 1);
+	}
+#endif
 }
 
 static inline void bw_env_follow_set_attack_tau(
diff --git a/include/bw_env_gen.h b/include/bw_env_gen.h
index 64bd229..bd008ba 100644
--- a/include/bw_env_gen.h
+++ b/include/bw_env_gen.h
@@ -20,7 +20,7 @@
 
 /*!
  *  module_type {{{ dsp }}}
- *  version {{{ 1.1.0 }}}
+ *  version {{{ 1.1.1 }}}
  *  requires {{{ bw_common bw_math bw_one_pole }}}
  *  description {{{
  *    Linear ADSR envelope generator.
@@ -42,6 +42,12 @@
  *    <ul>
  *      <li>Version <strong>1.1.0</strong>:
  *        <ul>
+ *          <li>Added debugging checks from <code>bw_env_gen_process()</code> to
+ *              <code>bw_env_gen_process_multi()</code>.</li>
+ *        </ul>
+ *      </li>
+ *      <li>Version <strong>1.1.0</strong>:
+ *        <ul>
  *          <li>Added skip_sustain and always_reach_sustain parameters.</li>
  *          <li>Now using <code>BW_NULL</code> and
  *              <code>BW_CXX_NO_ARRAY</code>.</li>
@@ -725,6 +731,10 @@ static inline void bw_env_gen_process_multi(
 	BW_ASSERT_DEEP(coeffs->state >= bw_env_gen_coeffs_state_reset_coeffs);
 	BW_ASSERT(state != BW_NULL);
 #ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT(state[i] != BW_NULL);
+		BW_ASSERT_DEEP(bw_env_gen_state_is_valid(coeffs, state[i]));
+	}
 	for (size_t i = 0; i < n_channels; i++)
 		for (size_t j = i + 1; j < n_channels; j++)
 			BW_ASSERT(state[i] != state[j]);
@@ -754,6 +764,12 @@ static inline void bw_env_gen_process_multi(
 
 	BW_ASSERT_DEEP(bw_env_gen_coeffs_is_valid(coeffs));
 	BW_ASSERT_DEEP(coeffs->state >= bw_env_gen_coeffs_state_reset_coeffs);
+#ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT_DEEP(bw_env_gen_state_is_valid(coeffs, state[i]));
+		BW_ASSERT_DEEP(y != BW_NULL && y[i] != BW_NULL ? bw_has_only_finite(y[i], n_samples) : 1);
+	}
+#endif
 }
 
 static inline void bw_env_gen_set_attack(
diff --git a/include/bw_fuzz.h b/include/bw_fuzz.h
index 8015e95..b8f5043 100644
--- a/include/bw_fuzz.h
+++ b/include/bw_fuzz.h
@@ -34,6 +34,8 @@
  *    <ul>
  *      <li>Version <strong>1.1.1</strong>:
  *        <ul>
+ *          <li>Added debugging checks from <code>bw_fuzz_process()</code> to
+ *              <code>bw_fuzz_process_multi()</code>.</li>
  *          <li>Added debugging checks in <code>bw_fuzz_process_multi()</code>
  *              to ensure that buffers used for both input and output appear at
  *              the same channel indices.</li>
@@ -544,6 +546,10 @@ static inline void bw_fuzz_process_multi(
 	BW_ASSERT_DEEP(coeffs->state >= bw_fuzz_coeffs_state_reset_coeffs);
 	BW_ASSERT(state != BW_NULL);
 #ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT(state[i] != BW_NULL);
+		BW_ASSERT_DEEP(bw_fuzz_state_is_valid(coeffs, state[i]));
+	}
 	for (size_t i = 0; i < n_channels; i++)
 		for (size_t j = i + 1; j < n_channels; j++)
 			BW_ASSERT(state[i] != state[j]);
@@ -551,6 +557,11 @@ static inline void bw_fuzz_process_multi(
 	BW_ASSERT(x != BW_NULL);
 	BW_ASSERT(y != BW_NULL);
 #ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT(x[i] != BW_NULL);
+		BW_ASSERT_DEEP(bw_has_only_finite(x[i], n_samples));
+		BW_ASSERT(y[i] != BW_NULL);
+	}
 	for (size_t i = 0; i < n_channels; i++)
 		for (size_t j = i + 1; j < n_channels; j++)
 			BW_ASSERT(y[i] != y[j]);
@@ -568,6 +579,12 @@ static inline void bw_fuzz_process_multi(
 
 	BW_ASSERT_DEEP(bw_fuzz_coeffs_is_valid(coeffs));
 	BW_ASSERT_DEEP(coeffs->state >= bw_fuzz_coeffs_state_reset_coeffs);
+#ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT_DEEP(bw_fuzz_state_is_valid(coeffs, state[i]));
+		BW_ASSERT_DEEP(bw_has_only_finite(y[i], n_samples));
+	}
+#endif
 }
 
 static inline void bw_fuzz_set_fuzz(
diff --git a/include/bw_gain.h b/include/bw_gain.h
index 08c07b0..453a0a4 100644
--- a/include/bw_gain.h
+++ b/include/bw_gain.h
@@ -29,6 +29,8 @@
  *    <ul>
  *      <li>Version <strong>1.1.1</strong>:
  *        <ul>
+ *          <li>Added debugging checks from <code>bw_ap1_process()</code> to
+ *              <code>bw_ap1_process_multi()</code>.</li>
  *          <li>Added debugging checks in <code>bw_gain_process_multi()</code>
  *              to ensure that buffers used for both input and output appear at
  *              the same channel indices.</li>
@@ -409,6 +411,11 @@ static inline void bw_gain_process_multi(
 	BW_ASSERT(x != BW_NULL);
 	BW_ASSERT(y != BW_NULL);
 #ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++) {
+		BW_ASSERT(x[i] != BW_NULL);
+		BW_ASSERT_DEEP(bw_has_only_finite(x[i], n_samples));
+		BW_ASSERT(y[i] != BW_NULL);
+	}
 	for (size_t i = 0; i < n_channels; i++)
 		for (size_t j = i + 1; j < n_channels; j++)
 			BW_ASSERT(y[i] != y[j]);
@@ -426,6 +433,10 @@ static inline void bw_gain_process_multi(
 
 	BW_ASSERT_DEEP(bw_gain_coeffs_is_valid(coeffs));
 	BW_ASSERT_DEEP(coeffs->state >= bw_gain_coeffs_state_reset_coeffs);
+#ifndef BW_NO_DEBUG
+	for (size_t i = 0; i < n_channels; i++)
+		BW_ASSERT_DEEP(bw_has_only_finite(y[i], n_samples));
+#endif
 }
 
 static inline void bw_gain_set_gain_lin(
diff --git a/include/bw_osc_pulse.h b/include/bw_osc_pulse.h
index 4b70183..5b06077 100644
--- a/include/bw_osc_pulse.h
+++ b/include/bw_osc_pulse.h
@@ -554,7 +554,7 @@ static inline char bw_osc_pulse_coeffs_is_valid(
 		return 0;
 
 #ifdef BW_DEBUG_DEEP
-	if (coeffs->state >= bw_gain_coeffs_state_reset_coeffs && !bw_one_pole_state_is_valid(&coeffs->smooth_coeffs, &coeffs->smooth_state))
+	if (coeffs->state >= bw_osc_pulse_coeffs_state_reset_coeffs && !bw_one_pole_state_is_valid(&coeffs->smooth_coeffs, &coeffs->smooth_state))
 		return 0;
 #endif
 
diff --git a/include/bw_osc_tri.h b/include/bw_osc_tri.h
index c2457fa..c4e2854 100644
--- a/include/bw_osc_tri.h
+++ b/include/bw_osc_tri.h
@@ -561,7 +561,7 @@ static inline char bw_osc_tri_coeffs_is_valid(
 		return 0;
 
 #ifdef BW_DEBUG_DEEP
-	if (coeffs->state >= bw_gain_coeffs_state_reset_coeffs && !bw_one_pole_state_is_valid(&coeffs->smooth_coeffs, &coeffs->smooth_state))
+	if (coeffs->state >= bw_osc_tri_coeffs_state_reset_coeffs && !bw_one_pole_state_is_valid(&coeffs->smooth_coeffs, &coeffs->smooth_state))
 		return 0;
 #endif