--- a/webaudio/specification.html	Tue Nov 13 12:57:02 2012 -0800
+++ b/webaudio/specification.html	Tue Nov 13 13:06:38 2012 -0800
@@ -2950,35 +2950,35 @@
 <dl>
   <dt id="dfn-threshold"><code>threshold</code></dt>
     <dd><p>The decibel value above which the compression will start taking
-      effect. </p>
+      effect.  Its default value is -24, with a nominal range of -100 to 0. </p>
     </dd>
 </dl>
 <dl>
   <dt id="dfn-knee"><code>knee</code></dt>
     <dd><p>A decibel value representing the range above the threshold where the
-      curve smoothly transitions to the "ratio" portion. </p>
+      curve smoothly transitions to the "ratio" portion. Its default value is 30, with a nominal range of 0 to 40. </p>
     </dd>
 </dl>
 <dl>
   <dt id="dfn-ratio"><code>ratio</code></dt>
-    <dd><p>The amount of dB change in input for a 1 dB change in output. </p>
+    <dd><p>The amount of dB change in input for a 1 dB change in output. Its default value is 12, with a nominal range of 1 to 20. </p>
     </dd>
 </dl>
 <dl>
   <dt id="dfn-reduction"><code>reduction</code></dt>
     <dd><p>A read-only decibel value for metering purposes, representing the
       current amount of gain reduction that the compressor is applying to the
-      signal. </p>
+      signal. If fed no signal the value will be 0 (no gain reduction).  The nominal range is -20 to 0. </p>
     </dd>
 </dl>
 <dl>
   <dt id="dfn-attack"><code>attack</code></dt>
-    <dd><p>The amount of time to reduce the gain by 10dB. </p>
+    <dd><p>The amount of time (in seconds) to reduce the gain by 10dB.   Its default value is 0.003, with a nominal range of 0 to 1. </p>
     </dd>
 </dl>
 <dl>
   <dt id="dfn-release"><code>release</code></dt>
-    <dd><p>The amount of time to increase the gain by 10dB. </p>
+    <dd><p>The amount of time (in seconds) to increase the gain by 10dB.  Its default value is 0.250, with a nominal range of 0 to 1. </p>
     </dd>
 </dl>
 </div>