diff --git a/encode.py b/encode.py
index 5ef4af5..52572d2 100755
--- a/encode.py
+++ b/encode.py
@@ -7,6 +7,8 @@ import shutil
 import subprocess
 import sys
 
+cleanup = True
+
 def get_videoduration(video):
     cmd = [
         'ffprobe',
@@ -52,6 +54,12 @@ def encode(xml, force=False, prefix='.'):
     public_mp4 = os.path.join(prefix, 'public', mp4.split('/')[-1][0].lower() + mp4.split('/')[-2] + '.1080p.mp4')
     public_mp4_480p = public_mp4.replace('.1080p.mp4', '.480p.mp4')
 
+    gongs = 'performance' in prefix
+    gongs_wav = mp4.replace('.mp4', '.gongs.wav')
+    gongs_left = mp4.replace('.mp4', '.gongs.right.wav')
+    gongs_right = mp4.replace('.mp4', '.gongs.left.wav')
+
+    force = True
 
     if force or is_new(xml, public_mp4):
         print(public_mp4)
@@ -61,7 +69,9 @@ def encode(xml, force=False, prefix='.'):
             'vcodec=libx264',
             'acodec=pcm_s16le'
         ]
-        subprocess.call(cmd)
+        if is_new(xml, video):
+            subprocess.call(cmd)
+
         duration = get_videoduration(video)
         cmd = [
             'ffmpeg', '-y', '-i', video,
@@ -69,24 +79,41 @@ def encode(xml, force=False, prefix='.'):
             '-map_channel', '0.1.1', right,
         ]
         subprocess.call(cmd)
+        if gongs:
+            cmd = [
+                'ffmpeg', '-y', '-i', gongs_wav,
+                '-map_channel', '0.0.0', gongs_left,
+                '-map_channel', '0.0.1', gongs_right,
+            ]
+            subprocess.call(cmd)
         cmd = [
             'qmelt', vocals_xml, '-consumer',
             'avformat:' + vocals,
             'acodec=pcm_s16le',
             'ac=1'
         ]
-        subprocess.call(cmd)
+        if is_new(xml, vocals):
+            subprocess.call(cmd)
         #for wav in (left, right, vocals):
         #    cmd = ['normalize-audio', wav]
         #    subprocess.call(cmd)
+        front_left = left
+        front_right = left
+        front_center = vocals
+        lfe = silence
+        back_left = vocals
+        back_right = vocals
+        if gongs:
+            back_left = gongs_left
+            back_right = gongs_right
         cmd = [
             'ffmpeg', '-y',
-            '-i', left,    # FL
-            '-i', right,   # FR
-            '-i', vocals,  # FC
-            '-i', silence, # LFE
-            '-i', vocals,  # BL
-            '-i', vocals,  # BR
+            '-i', front_left,    # FL
+            '-i', front_right,   # FR
+            '-i', front_center,  # FC
+            '-i', lfe,           # LFE
+            '-i', back_left,     # BL
+            '-i', back_right,    # BR
             '-filter_complex',
             '[0:0][1:0][2:0][3:0][4:0][5:0] amerge=inputs=6[aout]',
             '-map', "[aout]",
@@ -95,9 +122,13 @@ def encode(xml, force=False, prefix='.'):
             amix
         ]
         subprocess.call(cmd)
-        os.unlink(left)
-        os.unlink(right)
-        os.unlink(vocals)
+        if cleanup:
+            os.unlink(left)
+            os.unlink(right)
+            os.unlink(vocals)
+            if gongs:
+                os.unlink(gongs_left)
+                os.unlink(gongs_right)
 
         cmd = [
             'ffmpeg', '-y',
@@ -111,23 +142,25 @@ def encode(xml, force=False, prefix='.'):
             mp4
         ]
         subprocess.call(cmd)
-        os.unlink(video)
-        os.unlink(amix)
-        cmd = [
-            'ffmpeg', '-y',
-            '-i', mp4,
-            '-c:a', 'copy',
-            '-vf', 'scale=854:480',
-            '-c:v', 'libx264',
-            '-preset', 'medium',
-            '-b:v', '750k',
-            '-profile:v', 'high',
-            '-movflags', '+faststart',
-            mp4_480p
-        ]
-        subprocess.call(cmd)
+        if cleanup:
+            os.unlink(video)
+            os.unlink(amix)
+        if is_new(mp4, public_mp4_480p):
+            cmd = [
+                'ffmpeg', '-y',
+                '-i', mp4,
+                '-c:a', 'copy',
+                '-vf', 'scale=854:480',
+                '-c:v', 'libx264',
+                '-preset', 'medium',
+                '-b:v', '750k',
+                '-profile:v', 'high',
+                '-movflags', '+faststart',
+                mp4_480p
+            ]
+            subprocess.call(cmd)
+            shutil.move(mp4_480p, public_mp4_480p)
         shutil.move(mp4, public_mp4)
-        shutil.move(mp4_480p, public_mp4_480p)
         cmd = [
             './subtitles.py',
             '--prefix', prefix,
diff --git a/render_mlt.py b/render_mlt.py
index dc7b322..2189d1a 100755
--- a/render_mlt.py
+++ b/render_mlt.py
@@ -230,6 +230,7 @@ if version == 'performance':
 
     # mix gongs + music
     mtractor = mix_audio_tracks(gongs, music, 0.15)
+
 else:
     # mix drones + music
     mtractor = mix_audio_tracks(drones, music, 0.3)