after playing a lot with h_stack, h_vector & co, i realized that this work is too much complex to do in pd, and very easy to do in C.

so i coded these two external: notehigh and notelow. you can find them at http://xaero.ath.cx/cms/software

P.S.: i lost some data on my hdd. some time ago i posted another external named tension. since i lost code and ML archives, can someone search it and send to my address, so i put it on the website? thanks