You must use ASIO in order to have multiple outputs as Sound manager only has stereo out. In menu audio routing (through system menu) you can determine which audio output should be outputted through which output of your Quattro (the inputs are also routed there). Connect the instruments to the ports of the output module in the ensemble structure as needed. Also connect the input module there to your instruments which have audio input. Make sure to use the latest Reaktor updates (there are some important ASIO issues fixed), so the update 3.05 and the update 3.07 008 must be installed.