I’ve been trying to change the cutoff freq using MIDI but nothing seems to be working.
I’m able to use an expression pedal via Filter CV no problem. But I’m not able to change the value using cc19 like the manual says???
CC19 is the MSB (Most significant byte). Try CC51, the Filter Cutoff LSB.
CC19 (MSB) is correct.
The CC51 (LSB) range is about 1 digit of the CC19 range. So using CC51 might not cause any audible change at all.
The MSB is covering the whole range. The LSB is only the fine adjustment in between the values of one MSB digit.
So 128 times of full LSB range would be the same as the MSB range.
I don’t own a Sub 37 to check your original problem here. But I am working with MIDI since MIDI became available.
As far as I know CC19 is what I should use. My controller sends 0~127.
I can successfully use all other CCs and they do as expected, and I’ve confirmed that the CC19 is sent to the Sub37. But it doesn’t do nothing.
Altering the Cutoff with the filter CV works fine though. I tried sending CC19 while CV filter is plugged in or not and it doesn’t change anything.
Is there a setting somewhere? I’ve looked everywhere in the manual.
I’ve also been working with MIDI since 1992 
My mistake - you are correct. Thanks!
I was just playing around with CCs on the Sub 37. Something that hasn’t been mentioned here is the Mapping page. In the editor check the mapping page and make sure Filter Cutoff is assigned to CC19 as it should be. I’ve been doing the midi dance since 86/87 when I got the Roland S-50 and the MC-500. Good times.