diff --git a/src/modules/module-filter-chain/biquad.c b/src/modules/module-filter-chain/biquad.c
index c11f76e0d..644276bb0 100644
--- a/src/modules/module-filter-chain/biquad.c
+++ b/src/modules/module-filter-chain/biquad.c
@@ -326,10 +326,9 @@ void biquad_set(struct biquad *bq, enum biquad_type type, double freq, double Q,
 		double gain)
 {
 	/* Clear history values. */
+	bq->type = type;
 	bq->x1 = 0;
 	bq->x2 = 0;
-	bq->y1 = 0;
-	bq->y2 = 0;
 
 	switch (type) {
 	case BQ_LOWPASS:
diff --git a/src/modules/module-filter-chain/biquad.h b/src/modules/module-filter-chain/biquad.h
index 650b26395..3344598e6 100644
--- a/src/modules/module-filter-chain/biquad.h
+++ b/src/modules/module-filter-chain/biquad.h
@@ -10,21 +10,6 @@
 extern "C" {
 #endif
 
-/* The biquad filter parameters. The transfer function H(z) is (b0 + b1 * z^(-1)
- * + b2 * z^(-2)) / (1 + a1 * z^(-1) + a2 * z^(-2)).  The previous two inputs
- * are stored in x1 and x2, and the previous two outputs are stored in y1 and
- * y2.
- *
- * We use double during the coefficients calculation for better accuracy, but
- * float is used during the actual filtering for faster computation.
- */
-struct biquad {
-	float b0, b1, b2;
-	float a1, a2;
-	float x1, x2;
-	float y1, y2;
-};
-
 /* The type of the biquad filters */
 enum biquad_type {
 	BQ_NONE,
@@ -35,7 +20,23 @@ enum biquad_type {
 	BQ_HIGHSHELF,
 	BQ_PEAKING,
 	BQ_NOTCH,
-	BQ_ALLPASS
+	BQ_ALLPASS,
+	BQ_RAW,
+};
+
+/* The biquad filter parameters. The transfer function H(z) is (b0 + b1 * z^(-1)
+ * + b2 * z^(-2)) / (1 + a1 * z^(-1) + a2 * z^(-2)).  The previous two inputs
+ * are stored in x1 and x2, and the previous two outputs are stored in y1 and
+ * y2.
+ *
+ * We use double during the coefficients calculation for better accuracy, but
+ * float is used during the actual filtering for faster computation.
+ */
+struct biquad {
+	enum biquad_type type;
+	float b0, b1, b2;
+	float a1, a2;
+	float x1, x2;
 };
 
 /* Initialize a biquad filter parameters from its type and parameters.
diff --git a/src/modules/module-filter-chain/builtin_plugin.c b/src/modules/module-filter-chain/builtin_plugin.c
index 0d2ecaa1a..ba76f3267 100644
--- a/src/modules/module-filter-chain/builtin_plugin.c
+++ b/src/modules/module-filter-chain/builtin_plugin.c
@@ -287,7 +287,8 @@ static void bq_raw_update(struct builtin *impl, float b0, float b1, float b2,
 	bq->b2 = impl->b2 * a0;
 	bq->a1 = impl->a1 * a0;
 	bq->a2 = impl->a2 * a0;
-	bq->x1 = bq->x2 = bq->y1 = bq->y2 = 0.0;
+	bq->x1 = bq->x2 = 0.0f;
+	bq->type = BQ_RAW;
 }
 
 /*
@@ -1869,8 +1870,9 @@ static void *param_eq_instantiate(const struct fc_descriptor * Descriptor,
 	struct spa_json it[3];
 	const char *val;
 	char key[256], filename[PATH_MAX];
-	int i, len, res;
+	int len, res;
 	struct param_eq_impl *impl;
+	uint32_t i, n_bq = 0;
 
 	if (config == NULL) {
 		pw_log_error("param_eq: requires a config section");
@@ -1888,6 +1890,8 @@ static void *param_eq_instantiate(const struct fc_descriptor * Descriptor,
 		return NULL;
 
 	impl->rate = SampleRate;
+	for (i = 0; i < SPA_N_ELEMENTS(impl->bq); i++)
+		biquad_set(&impl->bq[i], BQ_NONE, 0.0f, 0.0f, 0.0f);
 
 	while ((len = spa_json_object_next(&it[0], key, sizeof(key), &val)) > 0) {
 		int32_t idx = 0;
@@ -1901,12 +1905,13 @@ static void *param_eq_instantiate(const struct fc_descriptor * Descriptor,
 			if (spa_atoi32(key+8, &idx, 0))
 				bq = &impl->bq[(SPA_CLAMP(idx, 1, 8) - 1) * PARAM_EQ_MAX];
 
-			res = load_eq_bands(filename, impl->rate, bq, PARAM_EQ_MAX, &impl->n_bq);
+			res = load_eq_bands(filename, impl->rate, bq, PARAM_EQ_MAX, &n_bq);
 			if (res < 0) {
 				pw_log_error("param_eq: failed to parse configuration from '%s'", filename);
 				goto error;
 			}
-			pw_log_info("loaded %d biquads for channel %d", impl->n_bq, idx);
+			pw_log_info("loaded %d biquads for channel %d", n_bq, idx);
+			impl->n_bq = SPA_MAX(impl->n_bq, n_bq);
 		}
 		else if (spa_strstartswith(key, "filters")) {
 			if (!spa_json_is_array(val, len)) {
@@ -1918,12 +1923,13 @@ static void *param_eq_instantiate(const struct fc_descriptor * Descriptor,
 			if (spa_atoi32(key+7, &idx, 0))
 				bq = &impl->bq[(SPA_CLAMP(idx, 1, 8) - 1) * PARAM_EQ_MAX];
 
-			res = parse_filters(&it[1], impl->rate, bq, PARAM_EQ_MAX, &impl->n_bq);
+			res = parse_filters(&it[1], impl->rate, bq, PARAM_EQ_MAX, &n_bq);
 			if (res < 0) {
 				pw_log_error("param_eq: failed to parse configuration");
 				goto error;
 			}
-			pw_log_info("parsed %d biquads for channel %d", impl->n_bq, idx);
+			pw_log_info("parsed %d biquads for channel %d", n_bq, idx);
+			impl->n_bq = SPA_MAX(impl->n_bq, n_bq);
 		} else {
 			pw_log_warn("param_eq: ignoring config key: '%s'", key);
 		}
diff --git a/src/modules/module-filter-chain/dsp-ops-c.c b/src/modules/module-filter-chain/dsp-ops-c.c
index 0a576ce9a..86dd9c779 100644
--- a/src/modules/module-filter-chain/dsp-ops-c.c
+++ b/src/modules/module-filter-chain/dsp-ops-c.c
@@ -115,6 +115,11 @@ void dsp_biquad_run_c(struct dsp_ops *ops, struct biquad *bq,
 	float b0, b1, b2, a1, a2;
 	uint32_t i;
 
+	if (bq->type == BQ_NONE) {
+		dsp_copy_c(ops, out, in, n_samples);
+		return;
+	}
+
 	x1 = bq->x1;
 	x2 = bq->x2;
 	b0 = bq->b0;