I'm trying to sync my Acidlab Miami and Roland TR-909 with Ableton as the master clock.
I've done this for many years but only with 1 drum machine and not 2.
I've set up 2 external instruments, with the hardware latency on the 909 external instrument set to 5ms to account for the start lag.
I've tested with the kicks off each machine and this leaves them nicely sync'ed.
So far so good... however, the problems arise when I try and adjust the Midi Clock Sync delay so that Ableton's metronome matches the kicks.
1. If I set it to -29ms and hit play then the kicks are still in sync but the metronome is out by a few ms.
2. If I adjust it on the fly (whilst it's still playing) to -26ms then it's 100% perfect (Ableton, Miami and 909 all sync'ed nicely)
3. But if I stop and start again (whilst still at -26ms) then it goes well out of time by at least 10ms. The drum machine kicks are also no longer in perfect sync even though I haven't changed their hardware latencies.
I've been doing some troubleshooting and basically, if I set the Midi Clock Sync delay to *anything* less than -29ms (even -28.5ms) then the timing goes screwy. But I need it to be -26ms for Ableton's metronome and the 2 machines to be spot on.
I get the same issue with Live 8 and Live 9, plus I've tried both USB and firewire audio interfaces.
This is driving me mental. Does anyone have any suggestions?
EDIT: I've actually found a sort of workaround. It's not ideal though. If I increase my audio interface's buffer from 4ms to 6ms then I increase the Midi Clock Sync Delay again to compensate(to -30ms), then it's all in-sync. Everything still goes weird if I go less than the -29ms "cutoff point" though.
I'd still like some help understanding and troubleshooting if anyone's reading this
