which one are you talking about ?
I know of 3 of them (and I can guess there are a few more out there):
dedynamic 0.2 which can be found at doom9's
http://doom9.org/software2.htm#audio
enhancer (winamp DSP plugin)
http://classic.winamp.com/plugins/de...ponentId=81361
compressor and wider (winamo DSP plugin)
http://www.rz.uni-frankfurt.de/~pesch/
I tested the 3 links within the last week, all of them were ok.
(The one I prefer is Enhancer)