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Logic 9 "Sample Accurate" Automation?

Discussion in 'Logic 9' started by Spandex, Oct 28, 2010.

  1. Spandex

    Spandex New Member

    Hi all.. I have a problem which I'm fairly sure is a bug.. or possibly a "feature" in the same sense that the crazy page formatting problems I used to get in MS Word were a "feature" :)

    When automating in Logic Pro 9, the automation doesn't happen where I expect it to. It happens later than where it was drawn in the track.

    http://spandex.dreamhosters.com/AutomationFail.logic.zip is a zip of the project file (uses the Klopfgeist metronome thingy + Adaptive Limiter)
    http://spandex.dreamhosters.com/AutomationFail.aif is the resulting 2 seconds of audio, which you can also listen to (and view the waveform) here:

    And this is a screenie of how the automation looks

    The automation should push the adaptive limiter into distortion just before beat 3 of the bar but, as you can hear (and see on the soundcloud player), it happens around 50ms after beat 3 has begun. I would expect, given how I drew the automation, for beats 1 and 2 to sound identical, then beats 3 and 4 to sound identical.

    Here are a few relevant preference screens too... I'm fairly sure everything's set right?

    It looks like the audio is compensated for the delay introduced by the plugin - but that the automation is not. So the supposedly "sample-accurate" automation is way out of sync... or possibly it's exactly in sync with the project timeline, but seems to be being applied to audio that has been shifted by PDC.

    If you can draw automation on top of MIDI, I'd expect them to both occur at the same time, rather than one be shifted and the other not?

    I deleted my prefs file as I've seen suggested elsewhere and it still occurs.

    And of course, this is just a simple example. In complex projects it can be *really* bad.. and is sometimes different when listening to the final rendered version.

    Having had this conversation on a couple of other (non-logic specific) forums, I think this is a known issue... where the graphical stuff isn't compensated for in the same way as the audio? So I guess my questions are:

    1) Am I doing something wrong, or is this really what Apple call "sample accurate automation"? :)

    2) If there's no simple fix, are there any tips and tricks with tracks/buses for mitigating this effect?
  3. JuanTahnahmahrah

    JuanTahnahmahrah Senior member

    I found the following white paper helpful in tweaking Logic so its arrange window is closer to being sample accurate:


    It may solve your issue, but is good to have in your reference regardless.
  4. Spandex

    Spandex New Member

    Yeah, I think I'm resigned to nothing actually fixing this (unless Apple do) - but hints on mitigating it and generally understanding the issues are greatly appreciated.

    Thanks.. I'll read and digest.

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