[this is a copy of what I posted the Propellerhead Reason Forum.]
When Reason is slaved to a DAW (tried multiple DAWS), and there is a tempo map in the DAW’s Conductor Track, some Reason notes either do not not sound or sound with decreased velocity or with changed Amp Decay or Sustain.
I seem to be able to make them sound by moving the notes later than right at the beginning of the measure/beat. But I have to move them as much as 23 units (frames or whatever the thousandths portion of the position indicator represents)…
But this obviously has an effect on the feel of the track, particularly obvious with bass voices.
To re-create the problem:
create a tempo map in a DAW that is rewire master… Have the tempo jump around from very slow tempos, like around 55bpm to faster tempos like 90bpm. Draw quantized notes in reason.
I know for certain this effects the Combinator patch called ‘Bass Player’ and the Subtractor patch called ‘Groove to This,’ but I’ve experienced this with other patches as well.
I’m running Digital Performer 8 and Reason 4 in 48kHz.
Things I’ve tried:
Switching DAWs (to Reaper)
Changing DAW Buffer Size and “host multiplier” buffer settings.
Changing Reason’s Default Sample Rate
Changing Reason’s Default Buffer Size
Repairing Disk Permissions.
Manually drawing a copy of DAW’s Tempo Map into Reason’s Transport Automation Lane while not rewired.
Moving notes later (seems to work, but not an acceptable solution)
[update] Tried moving to 44.1kHz… no dice