diff --git a/packages/superdough/helpers.mjs b/packages/superdough/helpers.mjs
index a3ba7df99..6278251d7 100644
--- a/packages/superdough/helpers.mjs
+++ b/packages/superdough/helpers.mjs
@@ -42,6 +42,7 @@ export const getParamADSR = (
   decay,
   sustain,
   release,
+  // min = value at start of attack, max = value at end of attack; it is possible that max < min
   min,
   max,
   begin,
@@ -59,17 +60,15 @@ export const getParamADSR = (
     max = max === 0 ? 0.001 : max;
   }
   const range = max - min;
-  const peak = max;
   const sustainVal = min + sustain * range;
   const duration = end - begin;
 
   const envValAtTime = (time) => {
     let val;
     if (attack > time) {
-      let slope = getSlope(min, peak, 0, attack);
-      val = time * slope + (min > peak ? min : 0);
+      val = time * getSlope(min, max, 0, attack) + min;
     } else {
-      val = (time - attack) * getSlope(peak, sustainVal, 0, decay) + peak;
+      val = (time - attack) * getSlope(max, sustainVal, 0, decay) + max;
     }
     if (curve === 'exponential') {
       val = val || 0.001;