The standard range for chimes (aka tubular bells) is middle C to F in the next higher octave. If you open the Halion Sonic VST window, it has the pitches an octave lower C2 to F3. To make those pitches sound in Dorico, you must write an octave lower than normal. See attached. That picture shows the pitches that sound. Notice that the out-of-range color applies to the first octave. You can use the EDIT page in Halion Sonic to shift the sounds by one octave. That works, but I presume that will reset if you re-apply the playback template.
Either Dorico or Halion needs to transpose by an octave so that this is automatic for the Dorico user. It looks to me like Halion is in error. I suppose Steinberg would be very reluctant to change that now because that would throw off any old Cubase projects that used tubular bells.
It there a way for Dorico to tell Halion to to the octave shift as Dorico is assigning the voice (when adding a new player/instrument or when applying the playback template)? That would seem to be the best solution if it were possible. The next best thing might be for Steinberg to supply a new sound ( i.e. “Chimes-correct”) that Dorico could use without disturbing all those old Cubase projects.
