Master-Slave audio issues

Hi All,

I am running my mac mini as a 'video slave' slaving to MTC from my main machine running Logic. The setup works great, it's easy and I like it but there is one issue that crops up.

Often the audio in the slave (the dialog of the movie or temp music) plays back at different pitches and speeds.

The picture remains in sync but the audio is drifting way off.

Am I right in thinking that I need one of those expensive clocks like a Big Ben?

I'm also not using an audio interface on the slave/mac mini, just the internal audio drive and the headphone out. If I were to buy a cheap small USB audio interface for the slave/mac mini and slave the clock (in audio midi setup) in that to the SPDIF output of my main audio interface on my main machine, would that stop the drift? (the transport would still be slaving to MTC in logic)

Any thoughts?

Open your project settings , then audio settings, and change the sync mode to either "MTC Trigger" or "External or Free". That will deal with the sample rate playback issues BUT your sync is not 100% accurate. On the other hand, I've done this and had sync remain between 2 computers for at least a 5 minute song length (I haven't tried for more because I haven't needed to".

As for an audio device, why not run VSL's VEPro? I'd suggest going to VSL's site and checking out the movies. VEPro is used by most of my clients now in Logic just fine, no issues.
Hey George,
Thanks very much for your suggestions.

In m project settings under sync mode my only options are: Internal, MTC or Manual.
I'm running 9.1.3 on both machines too.
Regarding Audio devices, I don't follow how the VE Pro would be an audio device? I have the VE Pro on my main machine.
I'm intrigued so if you could clarify I would be most grateful.


Under your AUDIO page in your Song Preferences... THAT is where the settings you need to look at are. Not Logic's MTC sync, the AUDIO sync, different thing altogether.

As for VEPro, go look at their movies. You use VEPRo as a slave to load your additional VIs..
Ah, thankyou. I was a little confused, (Does he mean Song Settings or Preferences (global).

I found it, Song Settings > SYNCHRONIZATION > Audio > Audio Sync Mode. -I had not noticed that setting before and that seems to have fixed it! Thank you!

I'm still a little foggy about why the VE Pro would be useful on the slave? Ah, ha, I think I realize what you are getting at. You mean using my mac mini as an AU host? I see.

My mac mini is a video Only slave but, actually, not a bad idea to use it as an AU host too. I haven't needed that so far. I actually just run the VE Pro in standalone mode running the Special Edition Plus (outside of Logic session) on my main machine, (ie. the same machine as my sequencer) and that is enough. Currently I don't need any more AU slaves than that but if I need more, I always could do that, so thanks.

Much appreciated for that tip, it seems that you fixed it! I haven't done rigorous testing but so far so good!
Hi there.
I am synchronising (slaving) an external sequencer, a Yamaha RS7000 with Logic Pro using Midi Machine Code MMC in the Logic synchronisation settings. (It doesn't read MTC in the mode I'm running, a long story) I'm looping a 32 bar sequence which works perfectly when the loop is from Bar 1 as Logic sends out a real time sequencer start message at Bar 1. Unfortunately when I try to loop from bar 33-65 it no longer locks in as Logic only sends out the sequencer start message at Bar 1.
Does anyone have any experience of this and know if you can insert a midi sequencer start message in a track at a position other than Bar 1 and what that midi message is?

Thanks All