Clean up Tige 21zx wake?

Hi, a friend of mine recently bought a tige 21zx. At his request I worked with him for a day trying to get the wakeboard wake to clean up. The best we have been able to do is get either the port or starboard wake to clean up, but not both at the same time. Does anybody have a recommendation for speed, ballast, line length, etc. for a good wakeboarding wake? Thanks!