We improved collision detection between two rigid bodies using a hierarchy of axis aligned bounding boxes (AABBs) and early split clipping. The technique was recently introduced for ray tracing and turned out to be very effective for collision detection. Early split clipping approximates each geometric primitive by a set of smaller and tighter fitting bounding boxes for hierarchy construction. We implemented the algorithm in a free collision detection library and extended it with an automatic termination criterion. Performance of collision detection with AABBs is improved up to two orders of magnitude for models with strongly varying triangle sizes.