This paper documents a method of controlling complex sound synthesis processes such as granular synthesis, additive synthesis, timbre morphology, swarm-based spatialisation, spectral spatialisation, and timbre spatialisation via a multi-parametric 2D interface. This paper evaluates the use of audio-rate control signals for sound synthesis, and discussing approaches to de-interleaving, synchronization, and mapping. The paper also outlines a number of ways of extending the expressivity of such a control interface by coupling this with another 2D multi-parametric nodes interface and audio-rate 2D table lookup. The paper proceeds to review methods of navigating multi-parameter sets via interpolation and transformation. Some case studies are finally discussed in the paper. The author has used this method to control complex sound synthesis processes that require control data for more that a thousand parameters.