diff --git a/media/libeffects/data/audio_effects.conf b/media/libeffects/data/audio_effects.conf
index d681c69..93f27cb 100644
--- a/media/libeffects/data/audio_effects.conf
+++ b/media/libeffects/data/audio_effects.conf
@@ -15,14 +15,18 @@
   visualizer {
     path /system/lib/soundfx/libvisualizer.so
   }
-  pre_processing {
-    path /system/lib/soundfx/libaudiopreprocessing.so
-  }
   downmix {
     path /system/lib/soundfx/libdownmix.so
   }
 }
 
+# Default pre-processing library. Add to audio_effect.conf "libraries" section if
+# audio HAL implements support for default software audio pre-processing effects
+#
+#  pre_processing {
+#    path /system/lib/soundfx/libaudiopreprocessing.so
+#  }
+
 # list of effects to load. Each effect element must contain a "library" and a "uuid" element.
 # The value of the "library" element must correspond to the name of one library element in the
 # "libraries" element.
@@ -79,19 +83,24 @@
     library downmix
     uuid 93f04452-e4fe-41cc-91f9-e475b6d1d69f
   }
-  agc {
-    library pre_processing
-    uuid aa8130e0-66fc-11e0-bad0-0002a5d5c51b
-  }
-  aec {
-    library pre_processing
-    uuid bb392ec0-8d4d-11e0-a896-0002a5d5c51b
-  }
-  ns {
-    library pre_processing
-    uuid c06c8400-8e06-11e0-9cb6-0002a5d5c51b
-  }
 }
+
+# Default pre-processing effects. Add to audio_effect.conf "effects" section if
+# audio HAL implements support for them.
+#
+#  agc {
+#    library pre_processing
+#    uuid aa8130e0-66fc-11e0-bad0-0002a5d5c51b
+#  }
+#  aec {
+#    library pre_processing
+#    uuid bb392ec0-8d4d-11e0-a896-0002a5d5c51b
+#  }
+#  ns {
+#    library pre_processing
+#    uuid c06c8400-8e06-11e0-9cb6-0002a5d5c51b
+#  }
+
 # Audio preprocessor configurations.
 # The pre processor configuration consists in a list of elements each describing
 # pre processor settings for a given input source. Valid input source names are: