diff --git a/spa/plugins/alsa/acp/acp.c b/spa/plugins/alsa/acp/acp.c
index 364d71eb0..f6f03a5ff 100644
--- a/spa/plugins/alsa/acp/acp.c
+++ b/spa/plugins/alsa/acp/acp.c
@@ -245,7 +245,7 @@ static void init_device(pa_card *impl, pa_alsa_device *dev, pa_alsa_direction_t
 		pa_proplist_update(dev->proplist, PA_UPDATE_REPLACE, m->input_proplist);
 	}
 	if (m->split) {
-		char pos[2048];
+		char pos[PA_CHANNELS_MAX*8];
 		struct spa_strbuf b;
 		int i;
 
@@ -1142,8 +1142,9 @@ static int hdmi_eld_changed(snd_mixer_elem_t *melem, unsigned int mask)
 		pa_proplist_unset(p->proplist, ACP_KEY_AUDIO_POSITION_DETECTED);
 	} else {
 		uint32_t positions[eld.lpcm_channels];
-		char position[64];
-		int i = 0, pos = 0;
+		char position[eld.lpcm_channels * 8];
+		struct spa_strbuf b;
+		int i = 0;
 
 		if (eld.speakers & 0x01) {
 			positions[i++] = ACP_CHANNEL_FL;
@@ -1172,16 +1173,14 @@ static int hdmi_eld_changed(snd_mixer_elem_t *melem, unsigned int mask)
 		if (eld.speakers & 0x10) {
 			positions[i++] = ACP_CHANNEL_RC;
 		}
-
 		while (i < eld.lpcm_channels)
 			positions[i++] = ACP_CHANNEL_UNKNOWN;
 
-		for (i = 0, pos = 0; i < eld.lpcm_channels; i++) {
-			pos += snprintf(&position[pos], sizeof(position) - pos, "%s,", channel_names[positions[i]]);
-		}
-
-		/* Overwrite trailing , */
-		position[pos - 1] = 0;
+		spa_strbuf_init(&b, position, sizeof(position));
+		spa_strbuf_append(&b, "[");
+		for (i = 0; i < eld.lpcm_channels; i++)
+			spa_strbuf_append(&b, "%s%s", i ? "," : "", channel_names[positions[i]]);
+		spa_strbuf_append(&b, "]");
 
 		changed |= (old_position == NULL) || (!spa_streq(old_position, position));
 		pa_proplist_sets(p->proplist, ACP_KEY_AUDIO_POSITION_DETECTED, position);
diff --git a/spa/plugins/alsa/acp/channelmap.h b/spa/plugins/alsa/acp/channelmap.h
index 2d4b54444..bb8f3f5f3 100644
--- a/spa/plugins/alsa/acp/channelmap.h
+++ b/spa/plugins/alsa/acp/channelmap.h
@@ -451,7 +451,6 @@ static inline int pa_channel_map_equal(const pa_channel_map *a, const pa_channel
 
 static inline char* pa_channel_map_snprint(char *s, size_t l, const pa_channel_map *map) {
     unsigned channel;
-    bool first = true;
     char *e;
     if (!pa_channel_map_valid(map)) {
         pa_snprintf(s, l, "%s", _("(invalid)"));
@@ -460,12 +459,10 @@ static inline char* pa_channel_map_snprint(char *s, size_t l, const pa_channel_m
     *(e = s) = 0;
     for (channel = 0; channel < map->channels && l > 1; channel++) {
         l -= pa_snprintf(e, l, "%s%s",
-                      first ? "" : ",",
+                      channel == 0 ? "" : ",",
                       pa_channel_position_to_string(map->map[channel]));
         e = strchr(e, 0);
-        first = false;
     }
-
     return s;
 }
 
diff --git a/spa/plugins/alsa/alsa-acp-device.c b/spa/plugins/alsa/alsa-acp-device.c
index 6ab41c8d2..44342a7a3 100644
--- a/spa/plugins/alsa/alsa-acp-device.c
+++ b/spa/plugins/alsa/alsa-acp-device.c
@@ -156,12 +156,13 @@ static int emit_node(struct impl *this, struct acp_device *dev)
 	const struct acp_dict_item *it;
 	uint32_t n_items, i;
 	char device_name[128], path[210], channels[16], ch[12], routes[16];
-	char card_index[16], card_name[64], *p;
+	char card_index[16], card_name[64];
 	char positions[MAX_CHANNELS * 12];
 	char codecs[512];
 	struct spa_device_object_info info;
 	struct acp_card *card = this->card;
 	const char *stream, *card_id, *bus;
+	struct spa_strbuf b;
 
 	info = SPA_DEVICE_OBJECT_INFO_INIT();
 	info.type = SPA_TYPE_INTERFACE_Node;
@@ -200,11 +201,13 @@ static int emit_node(struct impl *this, struct acp_device *dev)
 	snprintf(channels, sizeof(channels), "%d", dev->format.channels);
 	items[n_items++] = SPA_DICT_ITEM_INIT(SPA_KEY_AUDIO_CHANNELS, channels);
 
-	p = positions;
+	spa_strbuf_init(&b, positions, sizeof(positions));
+	spa_strbuf_append(&b, "[");
 	for (i = 0; i < dev->format.channels; i++) {
-		p += snprintf(p, 12, "%s%s", i == 0 ? "" : ",",
+		spa_strbuf_append(&b, "%s%s", i == 0 ? " " : ", ",
 				acp_channel_str(ch, sizeof(ch), dev->format.map[i]));
 	}
+	spa_strbuf_append(&b, " ]");
 	items[n_items++] = SPA_DICT_ITEM_INIT(SPA_KEY_AUDIO_POSITION, positions);
 
 	if (dev->n_codecs > 0) {
diff --git a/spa/plugins/alsa/alsa-pcm.c b/spa/plugins/alsa/alsa-pcm.c
index 676214685..309b2d91d 100644
--- a/spa/plugins/alsa/alsa-pcm.c
+++ b/spa/plugins/alsa/alsa-pcm.c
@@ -240,36 +240,33 @@ static int alsa_set_param(struct state *state, const char *k, const char *s)
 
 static int position_to_string(struct channel_map *map, char *val, size_t len)
 {
-	uint32_t i, o = 0;
+	uint32_t i;
 	char pos[8];
-	int r;
-	o += snprintf(val, len, "[ ");
+	struct spa_strbuf b;
+
+	spa_strbuf_init(&b, val, len);
+	spa_strbuf_append(&b, "[");
 	for (i = 0; i < map->n_pos; i++) {
-		r = snprintf(val+o, len-o, "%s%s", i == 0 ? "" : ", ",
+		spa_strbuf_append(&b, "%s%s", i == 0 ? " " : ", ",
 				spa_type_audio_channel_make_short_name(map->pos[i],
 					pos, sizeof(pos), "UNK"));
-		if (r < 0 || o + r >= len)
-			return -ENOSPC;
-		o += r;
 	}
-	if (len > o)
-		o += snprintf(val+o, len-o, " ]");
+	if (spa_strbuf_append(&b, " ]") < 2)
+		return -ENOSPC;
 	return 0;
 }
 
 static int uint32_array_to_string(uint32_t *vals, uint32_t n_vals, char *val, size_t len)
 {
-	uint32_t i, o = 0;
-	int r;
-	o += snprintf(val, len, "[ ");
-	for (i = 0; i < n_vals; i++) {
-		r = snprintf(val+o, len-o, "%s%d", i == 0 ? "" : ", ", vals[i]);
-		if (r < 0 || o + r >= len)
-			return -ENOSPC;
-		o += r;
-	}
-	if (len > o)
-		o += snprintf(val+o, len-o, " ]");
+	uint32_t i;
+	struct spa_strbuf b;
+
+	spa_strbuf_init(&b, val, len);
+	spa_strbuf_append(&b, "[");
+	for (i = 0; i < n_vals; i++)
+		spa_strbuf_append(&b, "%s%d", i == 0 ? " " : ", ", vals[i]);
+	if (spa_strbuf_append(&b, " ]") < 2)
+		return -ENOSPC;
 	return 0;
 }
 
diff --git a/src/pipewire/settings.c b/src/pipewire/settings.c
index 597e686a9..74d4cfcb2 100644
--- a/src/pipewire/settings.c
+++ b/src/pipewire/settings.c
@@ -245,24 +245,21 @@ void pw_settings_init(struct pw_context *this)
 static void expose_settings(struct pw_context *context, struct pw_impl_metadata *metadata)
 {
 	struct settings *s = &context->settings;
-	uint32_t i, o;
-	char rates[MAX_RATES*16] = "";
+	uint32_t i;
+	char rates[MAX_RATES*16];
+	struct spa_strbuf b;
 
 	pw_impl_metadata_set_propertyf(metadata,
 			PW_ID_CORE, "log.level", "", "%d", s->log_level);
 	pw_impl_metadata_set_propertyf(metadata,
 			PW_ID_CORE, "clock.rate", "", "%d", s->clock_rate);
-	for (i = 0, o = 0; i < s->n_clock_rates; i++) {
-		int r = snprintf(rates+o, sizeof(rates)-o, "%s%d", i == 0 ? "" : ", ",
+
+	spa_strbuf_init(&b, rates, sizeof(rates));
+	for (i = 0; i < s->n_clock_rates; i++)
+		spa_strbuf_append(&b, "%s%d", i == 0 ? "" : ", ",
 				s->clock_rates[i]);
-		if (r < 0 || o + r >= (int)sizeof(rates)) {
-			snprintf(rates, sizeof(rates), "%d", s->clock_rate);
-			break;
-		}
-		o += r;
-	}
 	if (s->n_clock_rates == 0)
-		snprintf(rates, sizeof(rates), "%d", s->clock_rate);
+		spa_strbuf_append(&b, "%d", s->clock_rate);
 
 	pw_impl_metadata_set_propertyf(metadata,
 			PW_ID_CORE, "clock.allowed-rates", "", "[ %s ]", rates);