the one and only proper way to do signal matrix multiplication with "iemmatrix" is to use [mtx_*~] (rather than [mtx_mul~], [mtx_mul_line~] or [matrix~]).
mtx_mul~ and mtx_*~ are equivalent, aren't they?
I thought they were. In Pc there is no [mtx_*~] file, so I use [mtx_mul~],
because it gets initialized with no problems.