MTC Sync via IAC Bus

This is continuing to drive me insane…!

For my own arcane reasons I need to sync Logic Pro X and Nuendo (I’ve tried 5.5.6 and 6.0.7) within my MacBook Pro. MTC via an IAC bus is the obvious choice.

When I press play in Logic, Nuendo joins in but with an offset. If I press stop in Logic, then Nuendo stops. Press play again, and Nuendo joins in again but picking up where it left off, plus an additional delay. Basically, Nuendo is syncing to MTC + [unidentified running clock time] - it seems be system up-time. Very, very odd.

If I use a third-party timecode app (Horae) it reads Logic’s output MTC fine, and Nuendo syncs perfectly to Horae with no offsets (and no offsets are set in the apps). If I set up two IAC busses and sync using Horae as a bridge then, also, it works. But direct IAC bus between the two apps - unusable, drifting offset.

I’ve looked at the MIDI signals using MIDIMonitor and all seems fine there - it’s just a very odd communication problem between these two apps.

Any thoughts? If not - any ideas whom I can ask? I really need an answer to this one.



Eventually solved by using Network MIDI instead of IAC.