Posted on 
Dec 12, 2002 01:13 pm As things are sped up, their frequencies change. This can make all the difference in your levels and the songs punchiness. As a song gets really sped up the frequencies mud together a little more making everything sound a little more naturally level.
However, I'm just going on the fly here and I wouldn't know for absolute sure, but that always seemed the reason to me. Hope I made a little sense.
