How do you control two vst synthesizers at once in fl studio?

i wanna do this because i want to make dubstep but am truly horrible at automation, and i know that artists like skrillex and excision use up two three synths at once.. i have the same synthesizers they use.. which is mainly just massive.. but how can i control two at once having one as that scratchy heavy feeling wobble with the low bass wobble since the synth cant really get the right sound on its own?