Stereo acoustical echo cancellation is a highly challenging application in the field of acoustical signal processing. Unlike the single-channel case, conflicting requirements on the adaptive filters make this problem ill-posed in its original formulation. In this contribution, it is shown how introducing an estimate of the common acoustical poles of the receiving room can lead the adaptive system to remarkable performance improvements with respect to the classical implementation. Finally, a detailed comparison between the two schemes is presented, based on a simulated acoustical environment and the use of the classical affine projection algorithm.