diff --git a/spa/plugins/audioconvert/merger.c b/spa/plugins/audioconvert/merger.c
index decb27c90..96936b6fa 100644
--- a/spa/plugins/audioconvert/merger.c
+++ b/spa/plugins/audioconvert/merger.c
@@ -53,9 +53,9 @@
 
 #define MAX_SAMPLES	8192
 #define MAX_ALIGN	16
-#define MAX_BUFFERS	64
-#define MAX_DATAS	32
-#define MAX_PORTS	128
+#define MAX_BUFFERS	32
+#define MAX_DATAS	64
+#define MAX_PORTS	64
 
 struct buffer {
 	uint32_t id;
@@ -116,7 +116,7 @@ struct impl {
 	unsigned int monitor:1;
 	unsigned int have_profile:1;
 
-	float empty[MAX_SAMPLES*2 + MAX_ALIGN];
+	float empty[MAX_SAMPLES + MAX_ALIGN];
 };
 
 #define CHECK_IN_PORT(this,d,p)		((d) == SPA_DIRECTION_INPUT && (p) < this->port_count)
diff --git a/spa/plugins/audioconvert/splitter.c b/spa/plugins/audioconvert/splitter.c
index 6877df8f6..81f48c9bc 100644
--- a/spa/plugins/audioconvert/splitter.c
+++ b/spa/plugins/audioconvert/splitter.c
@@ -52,9 +52,9 @@
 
 #define MAX_SAMPLES	8192
 #define MAX_ALIGN	16
-#define MAX_BUFFERS	64
-#define MAX_DATAS	32
-#define MAX_PORTS	128
+#define MAX_BUFFERS	32
+#define MAX_DATAS	64
+#define MAX_PORTS	64
 
 struct buffer {
 	uint32_t id;
@@ -116,7 +116,7 @@ struct impl {
 
 	bool have_profile;
 
-	float empty[MAX_SAMPLES*2 + MAX_ALIGN];
+	float empty[MAX_SAMPLES + MAX_ALIGN];
 };
 
 #define CHECK_OUT_PORT(this,d,p)	((d) == SPA_DIRECTION_OUTPUT && (p) < this->port_count)