Automating reason in sonar

alright guys small problem here, i want to automate the freq of filter 3 in the thor through x1, i done this before but cant remember how, i've got reasons midi implimentation chart and its number is 58, i go to the envelope filter on the midi track in sonar, go to automation, choose midi and assign 58, but its not controlling the cut off, i have it set to midi channel one, but to no avail, i done this before, but like i said cant remember how, help anyone please