freezing and stuttering transport


New Mixbuss User here, liking the sound and getting to know my way around Ardour.

Been mixing several tracks and all is pretty smooth, but on several projects the audio suddenly stutters and locks up,
then racing forward a few seconds, this seems to be happening around the 5 minute mark in most cases.
I also had some weird behaviour
with the loop points causing stuttering and freezing, sometimes crashing, so i tried removing the loop markers and other markers,
sometimes seemed to work, not always.

Any similar stories? Anything i can try?

Using Macbookpro 2.33 Ghz/ osx 10.4.11/ Apogee Duet


My setup I was testing Mixbus on is nearly identical to yours and I can’t say I was having that problem. What is your DSP load like around the time this is happening?


At first it seemed that it was the dsp maxing out, as it was reaching 100% percent at times with many AU plugs running, but it’s been happening on other projects, with hardly any plugs, and dsp around 40-50%. On 1 particular project with 1 guitar track it always stutters at exactly 5 min. and then races ahead a few seconds until it “catches” again. Every single time at the same point. Actually this was on 2 projects i can remember, and seemed to have nothing to do with dsp.
Very strange. The exported file was fine, but dealing with playback from within mixbuss was maddening.

To me it seems like a buffer (data throughput) problem. I had a similar problem once on a slowish USB drive, and lost of tracks.

When you export, jack is in free-wheeling mode, processing audio as fast as your system can handle the load, and then it comes out fine.

Try putting your audio on a dedicated external drive. Firewire works great, but the newer USB drives have worked for me as well.

I have all the audio on a very fast external drive, firewire 800, 7200 rpm.
Duet is plugged into the fw 400 slot so don’t know if that is an issue.

What’s weird is it stutters and freezes EVERY time at that same point, 5 min in the song, on more than 1 project.

It’s also just frozen and stuttered on 1 point, freezing up the program, spinning beach ball, have to force quit.

Otherwise, mixbus is great, i’m finding the eq very useful.

Yea this does not sound like an issue with drive speed, usually that will show up as a nice giant ERROR on the screen that stops transport and is really obvious exactly what went wrong. I don’t have an easy answer for you off hand. I know something similar showed up a long time ago, I am trying to remember the exact cause that was found for it. If I remember right it was sometyhing like the default loop marker or something of that nature, I really just have to look into it more.


Just realized something, i opened a new file and noticed that the default had the end marker at 5 min. -exactly where
song have been freezing/stuttering, when they were longer than 5 min.
Can this be confirmed or repeated by anyone? Seems to be a bug.

Also any idea of when an update of Mixbus will be happening? Would be great to sync plugins with the host tempo.

Thanks for the replies.

@elblanco: don’t get your hopes up about tempo sync. I was doing the implementation today, and Apple’s design seems very inadequate to me. It will work if you have no meter changes (and in some cases, no tempo changes either). Otherwise, I don’t see any way that the plugin can fully understand the tempo map. If you’re doing more complex music than a single tempo/meter, expect this to have issues.