diff --git a/js-programming/bytebeat-render.js b/js-programming/bytebeat-render.js
index c6f62c3..d0db6d3 100644
--- a/js-programming/bytebeat-render.js
+++ b/js-programming/bytebeat-render.js
@@ -76,7 +76,18 @@ const generateAudio = t => {
 
 const clamp = (a, b, c) => max(min(a, c), b)
 
-let lastCorrectSample = 127 // FIXME: guessed value
+let lastCorrectSample
+switch (SELECTED_TYPE) {
+case TYPE_BYTEBEAT:
+	lastCorrectSample = 127
+	break;
+case TYPE_SIGNED_BYTEBEAT:
+	lastCorrectSample = 0
+	break;
+case TYPE_FLOATBEAT:
+	lastCorrectSample = 0.0
+	break;
+}
 
 const constrainValue = sample => {
 	if (isNaN(sample) || sample < 0)