I'm not using a mixer. Just plugging in the speakers, plug the mic into the keyboard and that's pretty much all you need for private parties in rooms measuring about 1000 to 2000 square feet. Same holds true for the nursing homes, where most of the audience is wheel-chair bound and the room has the lousiest accustics on the planet. As Don said, the 2000s vocal effects are more than adequate for the smaller venues, and other than the harmonizer, they'll work on the larger jobs.

Cheers,

Gary