adds more voice harmonics

quantum/audio/voices.c

@@ -101,14 +101,27 @@ float voice_envelope(float frequency) {
             break;
         case duty_fifth_down:
             note_timbre = 0.5;
-            if ((envelope_index % 5) == 0)
+            if ((envelope_index % 3) == 0)
                 note_timbre = 0.75;
             break;
         case duty_fourth_down:
+            note_timbre = 0.0;
             if ((envelope_index % 12) == 0)
-                note_timbre = 0.25;
+                note_timbre = 0.75;
-            else
+            if (((envelope_index % 12) % 4) != 1)
+                note_timbre = 0.75;
+            break;
+        case duty_third_down:
+            note_timbre = 0.5;
+            if ((envelope_index % 5) == 0)
+                note_timbre = 0.75;
+            break;
+        case duty_fifth_third_down:
             note_timbre = 0.5;
+            if ((envelope_index % 5) == 0)
+                note_timbre = 0.75;
+            if ((envelope_index % 3) == 0)
+                note_timbre = 0.25;
             break;
 
 		default:

quantum/audio/voices.h

@@ -18,6 +18,8 @@ typedef enum {
     duty_octave_down,
     duty_fifth_down,
     duty_fourth_down,
+    duty_third_down,
+    duty_fifth_third_down,
     number_of_voices // important that this is last
 } voice_type;