well thats part of the soundcard hardware not shoutcast.
does the soundcard all you to recording using only left, right, center, left rear, or right rear ? If it has a setup or configuration that allows that, then you first need to do that. If you cant, then shoutcast can't do it for you, because when using shoutcast with your soundcard its the hardware configuration of the soundcard itself not software that controls the mixer settings.
~ According to the ship's log we're down to our last 3000 vomit bags.It'll never be enough.
search the forums! don't PM me on how-to, or ask me to setup you system. you do it so you learn.