Ableton Forum

there is a midi track controlling Reason

and a midi track controlling Impulse

They are both quantized and exactly 2 bars long and gradually they fall out of sync with each other.

This is the known Rewire latency problem.

There are two options:

1. Do ALL your Reason sequencing in the Reason sequencer or pattern devices and simply route the audio back to Live.

2. Use Live's midi clips, but do this: Set the rewire return audio channel to have a track delay greater than the maximum PDC time. This is the time set by Live to make sure all the VST effects are playing in time. This is unlikely to be greater than 60mS unless you are using some wacky convolution reverbs. So simply set all your rewire audio channels to a track delay of -60mS. Don't forget the minus sign.

But you must not do this for rewire channels coming from Reason sequencer controlled devices or Reason pattern devices. These must have their own rewire audio channel into Live and this must be set to a track delay of 0mS.

If you use a combination of Reason pattern devices and Live midi clip controlled Reason devices, then you must have two or more rewire audio channels available. You cannot mix them in Reason and hope they will stay in time.

Did that make sense? It took me some time to work it out too.

The worst thing is that if you mix Reason rack devices so that you have triggers generated by Redrum and use this to gate a midiclip controlled Reason synth, then all hell breaks loose.