Recent technological improvements in audio reproduction systems increased the possibilities to spatialize sources in a listening environment. The spatialization of reproduced audio is however highly dependent on the recording technique, the rendering method, and the loudspeaker configuration. While object-based audio production has proven to reduce the dependency on loudspeaker configurations, authoring tools are still considered to be difficult to interact with in current production environments. In this paper, we investigate the issues of spatialization techniques for object-based audio production and introduce the Spatial Audio Design Spaces (SpADS) framework, that provides insights into the spatial manipulation of object-based audio. Based on interviews with professional sound engineers, this morphological analysis clarifies the relationships between recording and rendering techniques that define audio-objects for 3D speaker configurations, allowing the analysis and the design of advanced object-based controllers as well.