diff --git a/const.h b/const.h
index 7d319d3..d23dfa9 100644
--- a/const.h
+++ b/const.h
@@ -16,10 +16,27 @@
 
 #define SAMPLE_RATE 44100.0f
 
-#define BPM_MIN 30.0f
-#define BPM_MAX 300.0f
-#define VCO_MIN 40.0f
-#define VCO_MAX 3200.0f
+#define BPM_MIN             30.0f
+#define BPM_MAX             300.0f
+
+#define VCO_FREQ_MIN        40.0f
+#define VCO_FREQ_MAX        3200.0f
+#define VCO_VOLUME_MIN      0.0f
+#define VCO_VOLUME_MAX      1.0f
+
+#define FILTER_FREQ_MIN     20.0f
+#define FILTER_FREQ_MAX     20000.0f
+#define FILTER_RES_MIN      0.0f
+#define FILTER_RES_MAX      1.0f
+
+#define ENV_ATTACK_MIN      0.001f      // 1ms
+#define ENV_ATTACK_MAX      10.0f       // 10s
+#define ENV_RELEASE_MIN     0.001f      // 1ms
+#define ENV_RELEASE_MAX     10.0f       // 10s
+
+#define REVERB_AMOUNT_MIN   0.0f
+#define REVERB_AMOUNT_MAX   1.0f
+
 
 #define otherwise else