diff --git a/spa/include/spa/utils/json.h b/spa/include/spa/utils/json.h
index b3e69eaa7..671918d6f 100644
--- a/spa/include/spa/utils/json.h
+++ b/spa/include/spa/utils/json.h
@@ -67,6 +67,8 @@ static inline void spa_json_enter(struct spa_json * iter, struct spa_json * sub)
 	*sub = SPA_JSON_ENTER(iter);
 }
 
+#define SPA_JSON_SAVE(iter) (struct spa_json) { (iter)->cur, (iter)->end, }
+
 /** Get the next token. \a value points to the token and the return value
  * is the length. */
 static inline int spa_json_next(struct spa_json * iter, const char **value)
diff --git a/src/daemon/filter-chain/sink-convolver.conf b/src/daemon/filter-chain/sink-convolver.conf
index 7c7c5865f..aa84b9801 100644
--- a/src/daemon/filter-chain/sink-convolver.conf
+++ b/src/daemon/filter-chain/sink-convolver.conf
@@ -36,6 +36,10 @@ context.modules = [
                         type = builtin
                         name = convolver
                         label = convolver
+			config = {
+			   filename = "src/modules/module-filter-chain/street2-L.wav"
+			   blocksize = 512
+			}
                     }
                 ]
             }
diff --git a/src/modules/module-filter-chain.c b/src/modules/module-filter-chain.c
index c9601e297..bce541aac 100644
--- a/src/modules/module-filter-chain.c
+++ b/src/modules/module-filter-chain.c
@@ -69,6 +69,9 @@ static const struct spa_dict_item module_props[] = {
 				"          name = <name> "
 				"          plugin = <plugin> "
 				"          label = <label> "
+				"          config = { "
+				"             <configkey> = <value> ... "
+				"          } "
 				"          control = { "
 				"             <controlname> = <value> ... "
 				"          } "
@@ -100,8 +103,6 @@ static const struct spa_dict_item module_props[] = {
 
 #include <pipewire/pipewire.h>
 
-#include "ladspa.h"
-
 #define MAX_HNDL 64
 #define MAX_PORTS 64
 #define MAX_CONTROLS 256
@@ -158,6 +159,7 @@ struct node {
 	struct descriptor *desc;
 
 	char name[256];
+	char *config;
 
 	struct port input_port[MAX_PORTS];
 	struct port output_port[MAX_PORTS];
@@ -352,16 +354,16 @@ static struct port *find_port(struct node *node, const char *name, int descripto
 	if (node == NULL)
 		return NULL;
 
-	if (LADSPA_IS_PORT_INPUT(descriptor)) {
-		if (LADSPA_IS_PORT_CONTROL(descriptor)) {
+	if (FC_IS_PORT_INPUT(descriptor)) {
+		if (FC_IS_PORT_CONTROL(descriptor)) {
 			ports = node->control_port;
 			n_ports = node->desc->n_control;
 		} else {
 			ports = node->input_port;
 			n_ports = node->desc->n_input;
 		}
-	} else if (LADSPA_IS_PORT_OUTPUT(descriptor)) {
-		if (LADSPA_IS_PORT_CONTROL(descriptor)) {
+	} else if (FC_IS_PORT_OUTPUT(descriptor)) {
+		if (FC_IS_PORT_CONTROL(descriptor)) {
 			ports = node->notify_port;
 			n_ports = node->desc->n_notify;
 		} else {
@@ -382,14 +384,26 @@ static struct port *find_port(struct node *node, const char *name, int descripto
 
 static struct spa_pod *get_prop_info(struct graph *graph, struct spa_pod_builder *b, uint32_t idx)
 {
+	struct impl *impl = graph->impl;
 	struct spa_pod_frame f[2];
 	struct port *port = graph->control_port[idx];
 	struct node *node = port->node;
 	struct descriptor *desc = node->desc;
 	const struct fc_descriptor *d = desc->desc;
 	struct fc_port *p = &d->ports[port->p];
+	float def, min, max;
 	char name[512];
 
+	if (p->hint & FC_HINT_SAMPLE_RATE) {
+		def = p->def * impl->rate;
+		min = p->min * impl->rate;
+		max = p->max * impl->rate;
+	} else {
+		def = p->def;
+		min = p->min;
+		max = p->max;
+	}
+
 	if (node->name[0] != '\0')
 		snprintf(name, sizeof(name), "%s:%s", node->name, p->name);
 	else
@@ -402,13 +416,13 @@ static struct spa_pod *get_prop_info(struct graph *graph, struct spa_pod_builder
 			SPA_PROP_INFO_name, SPA_POD_String(name),
 			0);
 	spa_pod_builder_prop(b, SPA_PROP_INFO_type, 0);
-	if (p->min == p->max) {
-		spa_pod_builder_float(b, p->def);
+	if (min == max) {
+		spa_pod_builder_float(b, def);
 	} else {
 		spa_pod_builder_push_choice(b, &f[1], SPA_CHOICE_Range, 0);
-		spa_pod_builder_float(b, p->def);
-		spa_pod_builder_float(b, p->min);
-		spa_pod_builder_float(b, p->max);
+		spa_pod_builder_float(b, def);
+		spa_pod_builder_float(b, min);
+		spa_pod_builder_float(b, max);
 		spa_pod_builder_pop(b, &f[1]);
 	}
 	spa_pod_builder_prop(b, SPA_PROP_INFO_params, 0);
@@ -452,7 +466,7 @@ static int set_control_value(struct node *node, const char *name, float *value)
 	struct port *port;
 	float old;
 
-	port = find_port(node, name, LADSPA_PORT_INPUT | LADSPA_PORT_CONTROL);
+	port = find_port(node, name, FC_PORT_INPUT | FC_PORT_CONTROL);
 	if (port == NULL)
 		return 0;
 
@@ -816,24 +830,24 @@ static struct descriptor *descriptor_load(struct impl *impl, const char *type,
 	for (p = 0; p < d->n_ports; p++) {
 		struct fc_port *fp = &d->ports[p];
 
-		if (LADSPA_IS_PORT_AUDIO(fp->flags)) {
-			if (LADSPA_IS_PORT_INPUT(fp->flags)) {
+		if (FC_IS_PORT_AUDIO(fp->flags)) {
+			if (FC_IS_PORT_INPUT(fp->flags)) {
 				pw_log_info("using port %lu ('%s') as input %d", p,
 						fp->name, desc->n_input);
 				desc->input[desc->n_input++] = p;
 			}
-			else if (LADSPA_IS_PORT_OUTPUT(fp->flags)) {
+			else if (FC_IS_PORT_OUTPUT(fp->flags)) {
 				pw_log_info("using port %lu ('%s') as output %d", p,
 						fp->name, desc->n_output);
 				desc->output[desc->n_output++] = p;
 			}
-		} else if (LADSPA_IS_PORT_CONTROL(fp->flags)) {
-			if (LADSPA_IS_PORT_INPUT(fp->flags)) {
+		} else if (FC_IS_PORT_CONTROL(fp->flags)) {
+			if (FC_IS_PORT_INPUT(fp->flags)) {
 				pw_log_info("using port %lu ('%s') as control %d", p,
 						fp->name, desc->n_control);
 				desc->control[desc->n_control++] = p;
 			}
-			else if (LADSPA_IS_PORT_OUTPUT(fp->flags)) {
+			else if (FC_IS_PORT_OUTPUT(fp->flags)) {
 				pw_log_info("using port %lu ('%s') as notify %d", p,
 						fp->name, desc->n_notify);
 				desc->notify[desc->n_notify++] = p;
@@ -863,6 +877,31 @@ exit:
 	return NULL;
 }
 
+/**
+ * {
+ *   ...
+ * }
+ */
+static int parse_config(struct node *node, struct spa_json *config)
+{
+	const char *val;
+	int len;
+
+	if ((len = spa_json_next(config, &val)) <= 0)
+		return len;
+
+	if (spa_json_is_null(val, len))
+		return 0;
+
+	if (spa_json_is_container(val, len))
+		len = spa_json_container_len(config, val, len);
+
+	if ((node->config = malloc(len+1)) != NULL)
+		spa_json_parse_string(val, len, node->config);
+
+	return 0;
+}
+
 /**
  * {
  *   "Reverb tail" = 2.0
@@ -914,12 +953,12 @@ static int parse_link(struct graph *graph, struct spa_json *json)
 			break;
 	}
 	def_node = spa_list_first(&graph->node_list, struct node, link);
-	if ((out_port = find_port(def_node, output, LADSPA_PORT_OUTPUT)) == NULL) {
+	if ((out_port = find_port(def_node, output, FC_PORT_OUTPUT)) == NULL) {
 		pw_log_error("unknown output port %s", output);
 		return -ENOENT;
 	}
 	def_node = spa_list_last(&graph->node_list, struct node, link);
-	if ((in_port = find_port(def_node, input, LADSPA_PORT_INPUT)) == NULL) {
+	if ((in_port = find_port(def_node, input, FC_PORT_INPUT)) == NULL) {
 		pw_log_error("unknown input port %s", input);
 		return -ENOENT;
 	}
@@ -968,13 +1007,16 @@ static void link_free(struct link *link)
  * name = rev
  * plugin = g2reverb
  * label = G2reverb
- * control = [
+ * config = {
  *     ...
- * ]
+ * }
+ * control = {
+ *     ...
+ * }
  */
 static int load_node(struct graph *graph, struct spa_json *json)
 {
-	struct spa_json control;
+	struct spa_json control, config;
 	struct descriptor *desc;
 	struct node *node;
 	const char *val;
@@ -984,6 +1026,7 @@ static int load_node(struct graph *graph, struct spa_json *json)
 	char plugin[256] = "";
 	char label[256] = "";
 	bool have_control = false;
+	bool have_config = false;
 	uint32_t i;
 
 	while (spa_json_get_string(json, key, sizeof(key)) > 0) {
@@ -1013,6 +1056,9 @@ static int load_node(struct graph *graph, struct spa_json *json)
 				return -EINVAL;
 			}
 			have_control = true;
+		} else if (spa_streq("config", key)) {
+			config = SPA_JSON_SAVE(json);
+			have_config = true;
 		} else if (spa_json_next(json, &val) < 0)
 			break;
 	}
@@ -1068,6 +1114,8 @@ static int load_node(struct graph *graph, struct spa_json *json)
 		port->p = desc->notify[i];
 		spa_list_init(&port->link_list);
 	}
+	if (have_config)
+		parse_config(node, &config);
 	if (have_control)
 		parse_control(node, &control);
 
@@ -1219,7 +1267,7 @@ static int setup_graph(struct graph *graph, struct spa_json *inputs, struct spa_
 		desc = node->desc;
 		d = desc->desc;
 		for (i = 0; i < n_hndl; i++) {
-			if ((node->hndl[i] = d->instantiate(d, impl->rate, NULL)) == NULL) {
+			if ((node->hndl[i] = d->instantiate(d, impl->rate, i, node->config)) == NULL) {
 				pw_log_error("cannot create plugin instance");
 				res = -ENOMEM;
 				goto error;
@@ -1244,7 +1292,6 @@ static int setup_graph(struct graph *graph, struct spa_json *inputs, struct spa_
 			}
 			if (d->activate)
 				d->activate(node->hndl[i]);
-
 		}
 		/* collect all control ports on the graph */
 		for (j = 0; j < desc->n_control; j++) {
@@ -1272,7 +1319,7 @@ static int setup_graph(struct graph *graph, struct spa_json *inputs, struct spa_
 				if (spa_streq(v, "null")) {
 					gp->desc = NULL;
 					pw_log_info("ignore input port %d", graph->n_input);
-				} else if ((port = find_port(first, v, LADSPA_PORT_INPUT)) == NULL) {
+				} else if ((port = find_port(first, v, FC_PORT_INPUT)) == NULL) {
 					res = -ENOENT;
 					pw_log_error("input port %s not found", v);
 					goto error;
@@ -1320,7 +1367,7 @@ static int setup_graph(struct graph *graph, struct spa_json *inputs, struct spa_
 				if (spa_streq(v, "null")) {
 					gp->desc = NULL;
 					pw_log_info("silence output port %d", graph->n_output);
-				} else if ((port = find_port(last, v, LADSPA_PORT_OUTPUT)) == NULL) {
+				} else if ((port = find_port(last, v, FC_PORT_OUTPUT)) == NULL) {
 					res = -ENOENT;
 					pw_log_error("output port %s not found", v);
 					goto error;
diff --git a/src/modules/module-filter-chain/builtin_plugin.c b/src/modules/module-filter-chain/builtin_plugin.c
index 81e33520b..19d500672 100644
--- a/src/modules/module-filter-chain/builtin_plugin.c
+++ b/src/modules/module-filter-chain/builtin_plugin.c
@@ -24,8 +24,9 @@
 
 #include <sndfile.h>
 
+#include <spa/utils/json.h>
+
 #include "plugin.h"
-#include "ladspa.h"
 
 #include "biquad.h"
 #include "convolver.h"
@@ -41,7 +42,7 @@ struct builtin {
 };
 
 static void *builtin_instantiate(const struct fc_descriptor * Descriptor,
-		unsigned long SampleRate, const char *config)
+		unsigned long SampleRate, int index, const char *config)
 {
 	struct builtin *impl;
 
@@ -78,11 +79,11 @@ static void copy_run(void * Instance, unsigned long SampleCount)
 static struct fc_port copy_ports[] = {
 	{ .index = 0,
 	  .name = "Out",
-	  .flags = LADSPA_PORT_OUTPUT | LADSPA_PORT_AUDIO,
+	  .flags = FC_PORT_OUTPUT | FC_PORT_AUDIO,
 	},
 	{ .index = 1,
 	  .name = "In",
-	  .flags = LADSPA_PORT_INPUT | LADSPA_PORT_AUDIO,
+	  .flags = FC_PORT_INPUT | FC_PORT_AUDIO,
 	}
 };
 
@@ -121,24 +122,24 @@ static void mixer_run(void * Instance, unsigned long SampleCount)
 static struct fc_port mixer_ports[] = {
 	{ .index = 0,
 	  .name = "Out",
-	  .flags = LADSPA_PORT_OUTPUT | LADSPA_PORT_AUDIO,
+	  .flags = FC_PORT_OUTPUT | FC_PORT_AUDIO,
 	},
 	{ .index = 1,
 	  .name = "In 1",
-	  .flags = LADSPA_PORT_INPUT | LADSPA_PORT_AUDIO,
+	  .flags = FC_PORT_INPUT | FC_PORT_AUDIO,
 	},
 	{ .index = 2,
 	  .name = "In 2",
-	  .flags = LADSPA_PORT_INPUT | LADSPA_PORT_AUDIO,
+	  .flags = FC_PORT_INPUT | FC_PORT_AUDIO,
 	},
 	{ .index = 3,
 	  .name = "Gain 1",
-	  .flags = LADSPA_PORT_INPUT | LADSPA_PORT_CONTROL,
+	  .flags = FC_PORT_INPUT | FC_PORT_CONTROL,
 	  .def = 1.0f, .min = 0.0f, .max = 10.0f
 	},
 	{ .index = 4,
 	  .name = "Gain 2",
-	  .flags = LADSPA_PORT_INPUT | LADSPA_PORT_CONTROL,
+	  .flags = FC_PORT_INPUT | FC_PORT_CONTROL,
 	  .def = 1.0f, .min = 0.0f, .max = 10.0f
 	},
 };
@@ -158,26 +159,26 @@ static const struct fc_descriptor mixer_desc = {
 static struct fc_port bq_ports[] = {
 	{ .index = 0,
 	  .name = "Out",
-	  .flags = LADSPA_PORT_OUTPUT | LADSPA_PORT_AUDIO,
+	  .flags = FC_PORT_OUTPUT | FC_PORT_AUDIO,
 	},
 	{ .index = 1,
 	  .name = "In",
-	  .flags = LADSPA_PORT_INPUT | LADSPA_PORT_AUDIO,
+	  .flags = FC_PORT_INPUT | FC_PORT_AUDIO,
 	},
 	{ .index = 2,
 	  .name = "Freq",
-	  .flags = LADSPA_PORT_INPUT | LADSPA_PORT_CONTROL,
-	  .hint = LADSPA_HINT_SAMPLE_RATE,
+	  .flags = FC_PORT_INPUT | FC_PORT_CONTROL,
+	  .hint = FC_HINT_SAMPLE_RATE,
 	  .def = 0.0f, .min = 0.0f, .max = 1.0f,
 	},
 	{ .index = 3,
 	  .name = "Q",
-	  .flags = LADSPA_PORT_INPUT | LADSPA_PORT_CONTROL,
+	  .flags = FC_PORT_INPUT | FC_PORT_CONTROL,
 	  .def = 0.0f, .min = 0.0f, .max = 10.0f,
 	},
 	{ .index = 4,
 	  .name = "Gain",
-	  .flags = LADSPA_PORT_INPUT | LADSPA_PORT_CONTROL,
+	  .flags = FC_PORT_INPUT | FC_PORT_CONTROL,
 	  .def = 0.0f, .min = -120.0f, .max = 5.0f,
 	},
 };
@@ -380,22 +381,47 @@ static const struct fc_descriptor bq_allpass_desc = {
 /** convolve */
 struct convolver_impl {
 	unsigned long rate;
-	LADSPA_Data *port[64];
+	float *port[64];
 
 	struct convolver *conv;
 };
 
 static void * convolver_instantiate(const struct fc_descriptor * Descriptor,
-		unsigned long SampleRate, const char *config)
+		unsigned long SampleRate, int index, const char *config)
 {
 	struct convolver_impl *impl;
 	SF_INFO info;
 	SNDFILE *f;
 	float *samples;
-	const char *filename;
+	int i, offset;
+	struct spa_json it[2];
+	const char *val;
+	char key[256];
+	char filename[PATH_MAX] = "";
+	int blocksize = 256;
+
+	if (config == NULL)
+		return NULL;
+
+	spa_json_init(&it[0], config, strlen(config));
+	if (spa_json_enter_object(&it[0], &it[1]) <= 0)
+		return NULL;
+
+	while (spa_json_get_string(&it[1], key, sizeof(key)) > 0) {
+		if (spa_streq(key, "filename")) {
+			if (spa_json_get_string(&it[1], filename, sizeof(filename)) <= 0)
+				return NULL;
+		}
+		else if (spa_streq(key, "blocksize")) {
+			if (spa_json_get_int(&it[1], &blocksize) <= 0)
+				return NULL;
+		}
+		else if (spa_json_next(&it[1], &val) < 0)
+			break;
+	}
+	if (!filename[0])
+		return NULL;
 
-	filename = "src/modules/module-filter-chain/convolve.wav";
-	filename = "src/modules/module-filter-chain/street2-L.wav";
 	spa_zero(info);
 	f = sf_open(filename, SFM_READ, &info) ;
 	if (f == NULL) {
@@ -415,7 +441,12 @@ static void * convolver_instantiate(const struct fc_descriptor * Descriptor,
 
 	sf_read_float(f, samples, info.frames);
 
-	impl->conv = convolver_new(256, samples, info.frames);
+	offset = index % info.channels;
+
+	for (i = 0; i < info.frames; i++)
+		samples[i] = samples[info.channels * i + offset];
+
+	impl->conv = convolver_new(blocksize, samples, info.frames);
 
 	free(samples);
 	sf_close(f);
@@ -424,7 +455,7 @@ static void * convolver_instantiate(const struct fc_descriptor * Descriptor,
 }
 
 static void convolver_connect_port(void * Instance, unsigned long Port,
-                        LADSPA_Data * DataLocation)
+                        float * DataLocation)
 {
 	struct convolver_impl *impl = Instance;
 	impl->port[Port] = DataLocation;
@@ -439,11 +470,11 @@ static void convolver_cleanup(void * Instance)
 static struct fc_port convolve_ports[] = {
 	{ .index = 0,
 	  .name = "Out",
-	  .flags = LADSPA_PORT_OUTPUT | LADSPA_PORT_AUDIO,
+	  .flags = FC_PORT_OUTPUT | FC_PORT_AUDIO,
 	},
 	{ .index = 1,
 	  .name = "In",
-	  .flags = LADSPA_PORT_INPUT | LADSPA_PORT_AUDIO,
+	  .flags = FC_PORT_INPUT | FC_PORT_AUDIO,
 	},
 };
 
diff --git a/src/modules/module-filter-chain/convolver.c b/src/modules/module-filter-chain/convolver.c
index 286ad57f0..00c4390d3 100644
--- a/src/modules/module-filter-chain/convolver.c
+++ b/src/modules/module-filter-chain/convolver.c
@@ -81,10 +81,6 @@ struct convolver *convolver_new(int block, const float *ir, int irlen)
 	conv->segCount = (irlen + conv->blockSize-1) / conv->blockSize;
 	conv->fftComplexSize = (conv->segSize / 2) + 1;
 
-	fprintf(stderr, "blockSize:%d segSize:%d segCount:%d fftComplexSize:%d\n",
-			conv->blockSize, conv->segSize, conv->segCount,
-			conv->fftComplexSize);
-
         conv->fft = kiss_fftr_f32_alloc(conv->segSize, 0, NULL, NULL);
         if (conv->fft == NULL)
                 return NULL;
@@ -156,9 +152,6 @@ int convolver_run(struct convolver *conv, const float *input, float *output, int
 		const int processing = SPA_MIN(len - processed, conv->blockSize - conv->inputBufferFill);
 		const int inputBufferPos = conv->inputBufferFill;
 
-		fprintf(stderr, "len:%d processing:%d fill:%d processed:%d\n",
-				len, processing, inputBufferPos, processed);
-
 		memcpy(conv->inputBuffer + inputBufferPos, input + processed, processing * sizeof(float));
 
 		memcpy(conv->fft_buffer, conv->inputBuffer, conv->blockSize * sizeof(float));
diff --git a/src/modules/module-filter-chain/ladspa_plugin.c b/src/modules/module-filter-chain/ladspa_plugin.c
index de042560e..b515ef9ea 100644
--- a/src/modules/module-filter-chain/ladspa_plugin.c
+++ b/src/modules/module-filter-chain/ladspa_plugin.c
@@ -48,7 +48,7 @@ struct descriptor {
 };
 
 static void *ladspa_instantiate(const struct fc_descriptor *desc,
-                        unsigned long SampleRate, const char *config)
+                        unsigned long SampleRate, int index, const char *config)
 {
 	struct descriptor *d = (struct descriptor *)desc;
 	return d->d->instantiate(d->d, SampleRate);
diff --git a/src/modules/module-filter-chain/plugin.h b/src/modules/module-filter-chain/plugin.h
index b773a4e5c..ab596778a 100644
--- a/src/modules/module-filter-chain/plugin.h
+++ b/src/modules/module-filter-chain/plugin.h
@@ -40,14 +40,24 @@ struct fc_plugin {
 struct fc_port {
 	uint32_t index;
 	const char *name;
+#define FC_PORT_INPUT	(1ULL << 0)
+#define FC_PORT_OUTPUT	(1ULL << 1)
+#define FC_PORT_CONTROL	(1ULL << 2)
+#define FC_PORT_AUDIO	(1ULL << 3)
 	uint64_t flags;
 
+#define FC_HINT_SAMPLE_RATE	(1ULL << 3)
 	uint64_t hint;
 	float def;
 	float min;
 	float max;
 };
 
+#define FC_IS_PORT_INPUT(x)	((x) & FC_PORT_INPUT)
+#define FC_IS_PORT_OUTPUT(x)	((x) & FC_PORT_OUTPUT)
+#define FC_IS_PORT_CONTROL(x)	((x) & FC_PORT_CONTROL)
+#define FC_IS_PORT_AUDIO(x)	((x) & FC_PORT_AUDIO)
+
 struct fc_descriptor {
 	const char *name;
 	uint64_t flags;
@@ -58,7 +68,7 @@ struct fc_descriptor {
 	struct fc_port *ports;
 
 	void *(*instantiate) (const struct fc_descriptor *desc,
-			unsigned long SampleRate, const char *config);
+			unsigned long SampleRate, int index, const char *config);
 
 	void (*cleanup) (void *instance);