diff --git a/js/recorderjs/recorderWorker.js b/js/recorderjs/recorderWorker.js
index c2c0802..57bdd51 100644
--- a/js/recorderjs/recorderWorker.js
+++ b/js/recorderjs/recorderWorker.js
@@ -141,13 +141,13 @@ function encodeWAV(samples, mono){
   /* sample format (raw) */
   view.setUint16(20, 1, true);
   /* channel count */
-  view.setUint16(22, mono?1:2, true);
+  view.setUint16(22, mono ? 1 : 2, true);
   /* sample rate */
   view.setUint32(24, sampleRate, true);
-  /* byte rate (sample rate * block align) */
-  view.setUint32(28, sampleRate * 4, true);
+  /* byte rate (sample rate * channels * bytes per sample) */
+  view.setUint32(28, sampleRate * (mono ? 1 : 2) * 2, true);
   /* block align (channel count * bytes per sample) */
-  view.setUint16(32, 4, true);
+  view.setUint16(32, (mono ? 1 : 2) * 2, true);
   /* bits per sample */
   view.setUint16(34, 16, true);
   /* data chunk identifier */