Hi Epu
I did not want this thread to die without an answer, but I am still trying to figure out what matrix modulation is. My current understanding is that it is like an intermediate between a controller and a destination. The controller controls the "matix" and the "matrix" controls the destination. I guess this can be convenient. However, Roland's implementation is not very thorough.
I used to think that matrix modulation meant you could route anything to anything, like on my old Kurzweil modules. That certainly is not possible with the 5080.