diff --git a/spa/include/spa/node/node.h b/spa/include/spa/node/node.h
index f3eb6c027..44e45da83 100644
--- a/spa/include/spa/node/node.h
+++ b/spa/include/spa/node/node.h
@@ -450,6 +450,9 @@ struct spa_node_methods {
 	 * Enumerate all possible parameters of \a id on \a port_id of \a node
 	 * that are compatible with \a filter.
 	 *
+	 * When SPA_ID_INVALID is given as the port_id, the node will reply with
+	 * the params that would be returned for a new port in the given direction.
+	 *
 	 * The result parameters can be queried and modified and ultimately be used
 	 * to call port_set_param.
 	 *
@@ -464,7 +467,7 @@ struct spa_node_methods {
 	 * \param seq a sequence number to pass to the result event when
 	 *	this method is executed synchronously.
 	 * \param direction an spa_direction
-	 * \param port_id the port to query
+	 * \param port_id the port to query or SPA_ID_INVALID
 	 * \param id the parameter id to query
 	 * \param start the first index to query, 0 to get the first item
 	 * \param max the maximum number of params to query
diff --git a/spa/plugins/audiomixer/audiomixer.c b/spa/plugins/audiomixer/audiomixer.c
index ed10f1a70..99d197f79 100644
--- a/spa/plugins/audiomixer/audiomixer.c
+++ b/spa/plugins/audiomixer/audiomixer.c
@@ -120,13 +120,16 @@ struct impl {
 };
 
 #define PORT_VALID(p)                ((p) != NULL && (p)->valid)
+#define CHECK_ANY_IN(this,d,p)       ((d) == SPA_DIRECTION_INPUT && (p) == SPA_ID_INVALID)
 #define CHECK_FREE_IN_PORT(this,d,p) ((d) == SPA_DIRECTION_INPUT && (p) < MAX_PORTS && !PORT_VALID(this->in_ports[(p)]))
 #define CHECK_IN_PORT(this,d,p)      ((d) == SPA_DIRECTION_INPUT && (p) < MAX_PORTS && PORT_VALID(this->in_ports[(p)]))
 #define CHECK_OUT_PORT(this,d,p)     ((d) == SPA_DIRECTION_OUTPUT && (p) == 0)
 #define CHECK_PORT(this,d,p)         (CHECK_OUT_PORT(this,d,p) || CHECK_IN_PORT (this,d,p))
+#define CHECK_PORT_ANY(this,d,p)     (CHECK_ANY_IN(this,d,p) || CHECK_PORT(this,d,p))
 #define GET_IN_PORT(this,p)          (this->in_ports[p])
 #define GET_OUT_PORT(this,p)         (&this->out_ports[p])
 #define GET_PORT(this,d,p)           (d == SPA_DIRECTION_INPUT ? GET_IN_PORT(this,p) : GET_OUT_PORT(this,p))
+#define GET_PORT_ANY(this,d,p)       (CHECK_ANY_IN(this,d,p) ? NULL : GET_PORT(this,d,p))
 
 static int impl_node_enum_params(void *object, int seq,
 			uint32_t id, uint32_t start, uint32_t num,
@@ -307,8 +310,7 @@ impl_node_remove_port(void *object, enum spa_direction direction, uint32_t port_
 	return 0;
 }
 
-static int port_enum_formats(void *object,
-			     enum spa_direction direction, uint32_t port_id,
+static int port_enum_formats(void *object, struct port *port,
 			     uint32_t index,
 			     struct spa_pod **param,
 			     struct spa_pod_builder *builder)
@@ -372,9 +374,9 @@ impl_node_port_enum_params(void *object, int seq,
 
 	spa_return_val_if_fail(this != NULL, -EINVAL);
 	spa_return_val_if_fail(num != 0, -EINVAL);
-	spa_return_val_if_fail(CHECK_PORT(this, direction, port_id), -EINVAL);
+	spa_return_val_if_fail(CHECK_PORT_ANY(this, direction, port_id), -EINVAL);
 
-	port = GET_PORT(this, direction, port_id);
+	port = GET_PORT_ANY(this, direction, port_id);
 
 	result.id = id;
 	result.next = start;
@@ -385,12 +387,12 @@ impl_node_port_enum_params(void *object, int seq,
 
 	switch (id) {
 	case SPA_PARAM_EnumFormat:
-		if ((res = port_enum_formats(this, direction, port_id, result.index, &param, &b)) <= 0)
+		if ((res = port_enum_formats(this, port, result.index, &param, &b)) <= 0)
 			return res;
 		break;
 
 	case SPA_PARAM_Format:
-		if (!port->have_format)
+		if (port == NULL || !port->have_format)
 			return -EIO;
 		if (result.index > 0)
 			return 0;
@@ -399,7 +401,7 @@ impl_node_port_enum_params(void *object, int seq,
 		break;
 
 	case SPA_PARAM_Buffers:
-		if (!port->have_format)
+		if (port == NULL || !port->have_format)
 			return -EIO;
 		if (result.index > 0)
 			return 0;
diff --git a/spa/plugins/audiomixer/mixer-dsp.c b/spa/plugins/audiomixer/mixer-dsp.c
index 420586a69..cb80379bc 100644
--- a/spa/plugins/audiomixer/mixer-dsp.c
+++ b/spa/plugins/audiomixer/mixer-dsp.c
@@ -115,13 +115,16 @@ struct impl {
 };
 
 #define PORT_VALID(p)                ((p) != NULL && (p)->valid)
+#define CHECK_ANY_IN(this,d,p)       ((d) == SPA_DIRECTION_INPUT && (p) == SPA_ID_INVALID)
 #define CHECK_FREE_IN_PORT(this,d,p) ((d) == SPA_DIRECTION_INPUT && (p) < MAX_PORTS && !PORT_VALID(this->in_ports[(p)]))
 #define CHECK_IN_PORT(this,d,p)      ((d) == SPA_DIRECTION_INPUT && (p) < MAX_PORTS && PORT_VALID(this->in_ports[(p)]))
 #define CHECK_OUT_PORT(this,d,p)     ((d) == SPA_DIRECTION_OUTPUT && (p) == 0)
 #define CHECK_PORT(this,d,p)         (CHECK_OUT_PORT(this,d,p) || CHECK_IN_PORT (this,d,p))
+#define CHECK_PORT_ANY(this,d,p)     (CHECK_ANY_IN(this,d,p) || CHECK_PORT(this,d,p))
 #define GET_IN_PORT(this,p)          (this->in_ports[p])
 #define GET_OUT_PORT(this,p)         (&this->out_ports[p])
 #define GET_PORT(this,d,p)           (d == SPA_DIRECTION_INPUT ? GET_IN_PORT(this,p) : GET_OUT_PORT(this,p))
+#define GET_PORT_ANY(this,d,p)       (CHECK_ANY_IN(this,d,p) ? NULL : GET_PORT(this,d,p))
 
 static int impl_node_enum_params(void *object, int seq,
 				 uint32_t id, uint32_t start, uint32_t num,
@@ -303,8 +306,7 @@ impl_node_remove_port(void *object, enum spa_direction direction, uint32_t port_
 	return 0;
 }
 
-static int port_enum_formats(void *object,
-			     enum spa_direction direction, uint32_t port_id,
+static int port_enum_formats(void *object, struct port *port,
 			     uint32_t index,
 			     struct spa_pod **param,
 			     struct spa_pod_builder *builder)
@@ -347,9 +349,9 @@ impl_node_port_enum_params(void *object, int seq,
 
 	spa_return_val_if_fail(this != NULL, -EINVAL);
 	spa_return_val_if_fail(num != 0, -EINVAL);
-	spa_return_val_if_fail(CHECK_PORT(this, direction, port_id), -EINVAL);
+	spa_return_val_if_fail(CHECK_PORT_ANY(this, direction, port_id), -EINVAL);
 
-	port = GET_PORT(this, direction, port_id);
+	port = GET_PORT_ANY(this, direction, port_id);
 
 	result.id = id;
 	result.next = start;
@@ -360,12 +362,12 @@ next:
 
 	switch (id) {
 	case SPA_PARAM_EnumFormat:
-		if ((res = port_enum_formats(this, direction, port_id, result.index, &param, &b)) <= 0)
+		if ((res = port_enum_formats(this, port, result.index, &param, &b)) <= 0)
 			return res;
 		break;
 
 	case SPA_PARAM_Format:
-		if (!port->have_format)
+		if (port == NULL || !port->have_format)
 			return -EIO;
 		if (result.index > 0)
 			return 0;
@@ -374,7 +376,7 @@ next:
 		break;
 
 	case SPA_PARAM_Buffers:
-		if (!port->have_format)
+		if (port == NULL || !port->have_format)
 			return -EIO;
 		if (result.index > 0)
 			return 0;
diff --git a/spa/plugins/control/mixer.c b/spa/plugins/control/mixer.c
index ec7237978..d744ca714 100644
--- a/spa/plugins/control/mixer.c
+++ b/spa/plugins/control/mixer.c
@@ -85,13 +85,16 @@ struct impl {
 };
 
 #define PORT_VALID(p)                ((p) != NULL && (p)->valid)
+#define CHECK_ANY_IN(this,d,p)       ((d) == SPA_DIRECTION_INPUT && (p) == SPA_ID_INVALID)
 #define CHECK_FREE_IN_PORT(this,d,p) ((d) == SPA_DIRECTION_INPUT && (p) < MAX_PORTS && !PORT_VALID(this->in_ports[(p)]))
 #define CHECK_IN_PORT(this,d,p)      ((d) == SPA_DIRECTION_INPUT && (p) < MAX_PORTS && PORT_VALID(this->in_ports[(p)]))
 #define CHECK_OUT_PORT(this,d,p)     ((d) == SPA_DIRECTION_OUTPUT && (p) == 0)
 #define CHECK_PORT(this,d,p)         (CHECK_OUT_PORT(this,d,p) || CHECK_IN_PORT (this,d,p))
+#define CHECK_PORT_ANY(this,d,p)     (CHECK_ANY_IN(this,d,p) || CHECK_PORT(this,d,p))
 #define GET_IN_PORT(this,p)          (this->in_ports[p])
 #define GET_OUT_PORT(this,p)         (&this->out_ports[p])
 #define GET_PORT(this,d,p)           (d == SPA_DIRECTION_INPUT ? GET_IN_PORT(this,p) : GET_OUT_PORT(this,p))
+#define GET_PORT_ANY(this,d,p)       (CHECK_ANY_IN(this,d,p) ? NULL : GET_PORT(this,d,p))
 
 static int impl_node_enum_params(void *object, int seq,
 				 uint32_t id, uint32_t start, uint32_t num,
@@ -269,8 +272,7 @@ impl_node_remove_port(void *object, enum spa_direction direction, uint32_t port_
 	return 0;
 }
 
-static int port_enum_formats(void *object,
-			     enum spa_direction direction, uint32_t port_id,
+static int port_enum_formats(void *object, struct port *port,
 			     uint32_t index,
 			     struct spa_pod **param,
 			     struct spa_pod_builder *builder)
@@ -318,19 +320,19 @@ next:
 
 	switch (id) {
 	case SPA_PARAM_EnumFormat:
-		if ((res = port_enum_formats(this, direction, port_id, result.index, &param, &b)) <= 0)
+		if ((res = port_enum_formats(this, port, result.index, &param, &b)) <= 0)
 			return res;
 		break;
 
 	case SPA_PARAM_Format:
-		if (!port->have_format)
+		if (port == NULL || !port->have_format)
 			return -EIO;
-		if ((res = port_enum_formats(this, direction, port_id, result.index, &param, &b)) <= 0)
+		if ((res = port_enum_formats(this, port, result.index, &param, &b)) <= 0)
 			return res;
 		break;
 
 	case SPA_PARAM_Buffers:
-		if (!port->have_format)
+		if (port == NULL || !port->have_format)
 			return -EIO;
 		if (result.index > 0)
 			return 0;
diff --git a/src/pipewire/impl-port.c b/src/pipewire/impl-port.c
index d0afcaa01..722f7b0ee 100644
--- a/src/pipewire/impl-port.c
+++ b/src/pipewire/impl-port.c
@@ -827,7 +827,8 @@ static int setup_mixer(struct pw_impl_port *port, const struct spa_pod *param)
 		return res;
 	}
 
-	pw_log_debug("mix node handle:%p iface:%p", handle, iface);
+	pw_log_debug("mix node %s (%s) handle:%p iface:%p", factory_name, fallback_lib,
+			handle, iface);
 	pw_impl_port_set_mix(port, (struct spa_node*)iface,
 			PW_IMPL_PORT_MIX_FLAG_MULTI |
 			PW_IMPL_PORT_MIX_FLAG_NEGOTIATE);