Question

I'm using a ddrum Trigger Interface via USB into Studio One 3's Impact, but my MIDI notes are apparently off by two tones.

Example.  If my High Tom sends D2 to play a sample, Studio One is receiving D0.  I have to tell the ddrum to send D4 in order so trigger the sample assigned to D2 in Impact.

Answer 1

Have you checked the MIDI monitor if the D2 trigger send a 90 32 xx message (instead of 90 1A xx)?
Note #32 = 50 = D2.