diff --git a/pkg/spxrpc/place_stream_playback_getvideo.go b/pkg/spxrpc/place_stream_playback_getvideo.go
index eec769013..af3e6fd4a 100644
--- a/pkg/spxrpc/place_stream_playback_getvideo.go
+++ b/pkg/spxrpc/place_stream_playback_getvideo.go
@@ -639,9 +639,10 @@ func trackPlaylistURL(uri, track, sid string, startMS, endMS *int64) string {
 func masterPlaylist(meta *vod.Metafile, uri, sid string, startMS, endMS *int64) string {
 	lines := []string{"#EXTM3U", "#EXT-X-VERSION:6", ""}
 
-	// Collect audio tracks in deterministic order, pick a default
-	// (prefer AAC since Safari is fussy about it).
-	audioIDs := tracksOfType(meta, "audio")
+	// Collect the full mix's audio tracks (stems are WebRTC-only, as in
+	// live HLS) in deterministic order, pick a default (prefer AAC since
+	// Safari is fussy about it).
+	audioIDs := mainAudioIDs(meta, tracksOfType(meta, "audio"))
 	defaultAudio := pickDefaultAudio(meta, audioIDs)
 	for _, tid := range audioIDs {
 		t := meta.Tracks[tid]
@@ -885,6 +886,22 @@ func tracksOfType(meta *vod.Metafile, t string) []string {
 	return out
 }
 
+// mainAudioIDs keeps the full mix's tracks among audioIDs: those in the
+// lowest audio group.
+func mainAudioIDs(meta *vod.Metafile, audioIDs []string) []string {
+	var main []string
+	for _, id := range audioIDs {
+		g := meta.Tracks[id].Group
+		switch {
+		case len(main) == 0 || g < meta.Tracks[main[0]].Group:
+			main = []string{id}
+		case g == meta.Tracks[main[0]].Group:
+			main = append(main, id)
+		}
+	}
+	return main
+}
+
 // pickDefaultAudio prefers an AAC track (Safari requires it) and
 // falls back to the first audio track. Returns "" if no audio.
 func pickDefaultAudio(meta *vod.Metafile, audioIDs []string) string {
diff --git a/pkg/spxrpc/place_stream_playback_getvideo_test.go b/pkg/spxrpc/place_stream_playback_getvideo_test.go
index cbd5046ef..a4859ba53 100644
--- a/pkg/spxrpc/place_stream_playback_getvideo_test.go
+++ b/pkg/spxrpc/place_stream_playback_getvideo_test.go
@@ -104,6 +104,22 @@ func TestMasterPlaylist_PropagatesTimeRange(t *testing.T) {
 	require.Contains(t, pl, "end=2000")
 }
 
+// A recording with stems lists only the full mix (the lowest audio group),
+// even when a stem's AAC comes first by track id: HLS has no stem mixing.
+func TestMasterPlaylist_FullMixOnly(t *testing.T) {
+	meta := fixtureMetafile()
+	stem := meta.Tracks["2"]
+	stem.Group = 2
+	meta.Tracks["2"] = stem
+	mix := stem
+	mix.Group = 1
+	meta.Tracks["3"] = mix
+	pl := masterPlaylist(meta, fixtureURI, fixtureSID, nil, nil)
+	require.Equal(t, 1, strings.Count(pl, "#EXT-X-MEDIA:TYPE=AUDIO"), pl)
+	require.Contains(t, pl, "track=3")
+	require.NotContains(t, pl, "track=2")
+}
+
 func TestMediaPlaylist_Video(t *testing.T) {
 	pl, err := mediaPlaylist(fixtureMetafile(), "1", fixtureDID, fixtureSID, vodCDN{}, nil, nil)
 	require.NoError(t, err)
diff --git a/pkg/vod/metafile.go b/pkg/vod/metafile.go
index 96bf46783..19bc661ee 100644
--- a/pkg/vod/metafile.go
+++ b/pkg/vod/metafile.go
@@ -93,6 +93,9 @@ type MetafileTrack struct {
 	// Audio-only.
 	Channels   uint32 `json:"channels,omitempty"`
 	SampleRate uint32 `json:"sampleRate,omitempty"`
+	// Group is the track's alternateGroup: the lowest is the full mix,
+	// higher ones are stems (absent on older metafiles: all one group).
+	Group uint32 `json:"group,omitempty"`
 }
 
 // MetafileSegment is one GOP-sized byte range within the blob.
@@ -282,6 +285,7 @@ func (b *metafileBuilder) Finalize(cid string, size int64) *Metafile {
 							track.Timescale = c.Timescale()
 							track.Channels = c.NumberOfChannels
 							track.SampleRate = c.SampleRate
+							track.Group = c.AlternateGroup
 							break
 						}
 					}