This paper describes a very efficient software tool for use in real-time multichannel convolution. This software is applied to the reproduction of Ambiophonic surround sound. The program runs on a Windows-based PC using compatible sound cards. The binaural input signal is acquired by the sound card, then processed by the software, producing outputs for the stereo dipole and for the surround loudspeakers. Using state-of-the-art PCs is possible to achieve setups with more than ten loudspeakers and to simulate room impulse responses larger than one second.