Assigning Sounds to the 8 output expander

Im a newbie so pardon my question. I finally upgraded to the 8outputs but now when i assign a sound to an output it plays on the output channel and the main channel. I obviously wanna send it to the output and edit the sound from my mixer. How can i accomplish this and only hear the sound from the output and not also the main stereo output???

thanks in advance

re\posted this in the newbie section - sorry posted it in wrong section.

no problem guy