Renoise with ReWire and PDC - big problems?

Hi folks,

I’m attempting to marry Renoise with Ableton Live via ReWire, where Renoise is the master and Live is simply a convenient sampler/warp tool. I am seeing quite big discrepancies in the timing when I have a reasonably heavy Renoise project loaded. In this project there are plenty of latency hog plugs etc - it’s out of sync and obviously so.

It is starkly apparent that the latency accrued inside Renoise is not being accounted for with the Live/Renoise ReWire sync.

Anyone else out there having problems with sync inside a ReWire relationship?

Interestingly, the timing problems seem to be fixed if Ableton Live is the ReWire master with Renoise being the slave.

If it’s the other way around, the more plugins and latency I introduce inside Renoise, the further out of sync the audio goes with Live.

I’ve stumbled upon a similar problem when running Renoise as slave to Studio One.

I found this info from taktik on the forum, which almost helped:

— Dealing with Latency caused by PDC as ReWire Slave

When running Renoise as ReWire slave, and you are using some FX which do introduce latencies (like compressors, master tools or some special reverbs), Renoise will compensate those latencies via PDC just like it does when running standalone.
Unfortunately ReWire does not directly support PDC, so Renoise has to trick a bit to get stuff played back by Renoise & the master in sync. There are two modes on how to deal with the overall PDC latency, which can be changed in the Audio Preferences Pane, only when running as ReWire slave:

  • Enabling the “Automatically compensate latencies” option will make sure that Renoise & your Master are always synced up, whatever latency Renoise is running at. This has the sideeffect, that Renoise has to shift its timeline before the masters. This means that when starting in the master at beat pos 1.1.1, Renoise will start a bit later, so any notes on 1.1.1 in Renoise might be missed.
  • Disabling the “Automatically compensate latencies” will avoid such time shifts. Thus Renoise will not play in sync with the master, but it will also not miss any notes. You should use this option, when you can compensate Renoises latency in the master itself, by for example shifting all tracks Renoise is playing at by the specified latency back. Or when the latencies are so small that you simply want to ignore them - this will be the case ost of the time.
    Another solution to this problem is to enabling the “Automatically compensate latencies” option, and later, while working on something, en/disable PDC in Renoise, just like you need it.

It seems that the Renoise trick doesn’t always work that well, so it might be worth trying. Sadly, the sync is still roughly 15ms off here ;( That’s way too much… S1 isn’t slaveable so I seem to be doomed trying to rewire Renoise here.