Help get this topic noticed by sharing it on Twitter, Facebook, or email.
I’m frustrated

MPC Live Bug: Changing sequences causes MPC clock to drift out of sync when using Ableton Link

I've been testing this for hours now and can confirm when outputting MIDI clock from one of the MIDI out ports (in order to slave other hardware to the MPC), if you have your internal sync set to Ableton Link, the MIDI clock output drifts slowly each time you change sequences.

WIth the MPC's sync set to Ableton Link, I made 2 simple 4 bar sequence loops, and switching back and forth between them you can slowly hear the external gear turn out of sync. I have tried this with several different sequencers and its clear that the MPC Live is causing the drift.

If I turn the MPC's sync to OFF, the drift problem is resolved. Switching between sequences does not introduce any sort of clock drift.

Regardless of whether you are actually connected to other Ableton Link devices or not, anytime the MPC's clock is set to Ableton Link this clock drift is introduced.

I've been trying to use my Force and Live together sync'd with Ableton Link, which is really great, until you introduce other gear into this setup and then it becomes a problem.

As well documented now, the MPC Live/X/Force do not slave well to other external gear. As I have measured in previous tests, there is significant clock jitter which makes tight timing drum programming nearly impossible. Also when you slave Force to an external clock, it can no longer record audio clips.
3 people have
this problem
+1
Reply
  • ***Update, after more further testing I have discovered this is a bug simply when using Ableton Link, regardless of whether you are connected to external gear or not.

    When the MPC sync is set to Ableton Link, switching between sequences introduces a very small delay in timing when beginning a new sequence. When you switch sequences multiple times, the MPC is very obviously out of sync with other Ableton Link gear. When you stop and start the MPC again, the timing corrects itself.

    I performed this test with my MPC Live Sync'd via Ableton Link to my Akai Force hardware. I pressed play on both units simultaneously and both started together as per how Ableton Link functions.

    On the MPC I made 2 different sequences each 4 bars in length, and I manually switched between them every 4 bars once each finished. After a few switches I could start to hear some timing discrepancy. And after about 2 minutes of switching it was very obvious the MPC was totally out of sync with the Force. I double checked by turning both MPC and Force metronomes on and indeed they were heavily out of sync.

    Once I pressed stop on the MPC, and then pressed play again, the sequences started in sync and everything was fixed.

    I love in theory how Ableton Link can sync these devices but right now it is clearly not working properly by causing this sync problem.

    As in my original post, I recreated this test again syncing both MPC and Force to an external sequencer (Cirklon) and when switching sequences on the MPC it always stated in sync, even after 15+ minutes of sequence switching testing.

    It has to be a bug with the way MPC Live syncs using Ableton Link.
  • (some HTML allowed)
    How does this make you feel?
    Add Image
    I'm

    e.g. sad, anxious, confused, frustrated kidding, amused, unsure, silly happy, confident, thankful, excited indifferent, undecided, unconcerned

  • I have the same issue when I click anything on the Force it kicks out midi sync.. what an expensive paper weight!
  • (some HTML allowed)
    How does this make you feel?
    Add Image
    I'm

    e.g. sad, anxious, confused, frustrated kidding, amused, unsure, silly happy, confident, thankful, excited indifferent, undecided, unconcerned

  • Hey analoguebubblebath,

    Thanks for posting!

    I've recreated the steps you outlined above and was not able to replicate the issue you described. I absolutely believe that you're experiencing drift with Ableton Link, though. Clock over WIFI is a fickle thing. All data over WIFI, coming from any device that is connected, musical or not, is cued in the order received. This is problematic for clocks as receiving a timing pulse a little later than anticipated will offset the clocks, compounding in a very noticeable drift as the session proceeds. It doesn't provide a reliable measure of time as the clock is subject to all other data streams, pushing and pulling the timing in different ways. It's not the steadiest of methods.

    Moreover, if you don't have the Force enabled to receive transport commands from the Live you can't be entirely sure that play was engaged at the exact same moment for both devices. This is complicated even yet as Ableton Link does not designate a master clock. It's a virtual Cumbayah of BPMs shifting according to which device made the most recent change.

    I totally understand that Link is a convenient way of syncing mulitple devices. However, for use in the studio with more intricate production where timing and clock accuracy are a necessity, a hardwired connection sending/receiving MC is preferable.

    That said, I will certainly forward your comments and concerns to the team for further consideration!

    Let me know if you have any questions!
    • Hi Eliza, thanks for getting back to me. I think you may be mis-interpreting the clock drift issues I am experiencing as a problem with Ableton Link in General. Before Ableton Link was created, WIFI clocks were inherently unstable as you mentioned, dealing with messaging cue order and such. The creation of Ableton Link actually created an incredibly stable WIFI clock source, and thus has been my extensive experience using it on multiple computers/hardware units.

      With my MPC Live and Force connected to Ableton via Ableton Link, the timing is rock solid for endless amounts of time letting the hardware units play. I and many others have measured the clock accuracy as extremely tight. This explains how the Force and MPC can be sync'd to Live and play for any amount of time in perfect sync, that is until you start changing sequences.

      On the MPC, repeating the same 2 bar looped sequence plays in perfect time for hours and hours. The timing begins to drift however the moment you switch sequences on the MPC. Something is happening when starting a new sequence that creates some sort of start delay. Its very short and hard to notice at first after only a few switches. But if you switch back and forth between 2 sequences again and again for a few minutes, you will hear that the timing is drifting on the MPC in comparison to the Force and/or Ableton Live. The Force and Ableton Live are still in perfect sync. Thus, the only thing causing this clock drift is changing sequence on the MPC. If you stop playback on the MPC, and then start again, it restarts properly at the bar start point in perfect sync. And continues to playback in perfect sync, until you start changing sequences again. This performance points to the issue being with sequence changing and not Ableton Link itself. Again how would it be able to stay in perfect sync for so long without changing sequences?

      To further support this evidence, if you are outputting MIDI clock data through one of the rear ports on the MPC Live, the MIDI clock data actually stays in perfect sync with Ableton Link connections while the MPC's internal clock drifts from changing sequences. This is very bizarre behavior since the MIDI clock output should always be in 100% sync with the MPC's internal clock timing. Why would these timings be separated for any reason?

      In the extensive amount of sync setup testing I have been doing its becoming very clear that the clock drift issue is on the MPC from changing sequences. Again why would it stay in perfect sync forever until you start changing sequences?

      When the MPC is sync'd to an external clock, changing sequences does not cause any clock drift, and the MPC stays in close sync with the MIDI Clock it is slaved to. However when syncing the MPC to Force via MIDI cable, there is a small amount of MIDI clock latency introduced which does not allow the two devices to tightly sync together without using a hardware "midi clock shift" device, such as the ERM Multiclock. And even when using the timing correction device to get the devices tightly sync'd, the Force will not record audio clips when sync'd to an external clock like it will when sync'd to Ableton Link.
  • (some HTML allowed)
    How does this make you feel?
    Add Image
    I'm

    e.g. sad, anxious, confused, frustrated kidding, amused, unsure, silly happy, confident, thankful, excited indifferent, undecided, unconcerned

  • You said, "I totally understand that Link is a convenient way of syncing mulitple devices. However, for use in the studio with more intricate production where timing and clock accuracy are a necessity, a hardwired connection sending/receiving MC is preferable. "

    Absolutely crucial i agree! The FORCE cant even do this in MIDI master mode:
    https://www.dropbox.com/sh/rzm5s7vylk...

    As you can see if I click any of the menu buttons the midi loses sync so its unusable for me!
  • (some HTML allowed)
    How does this make you feel?
    Add Image
    I'm

    e.g. sad, anxious, confused, frustrated kidding, amused, unsure, silly happy, confident, thankful, excited indifferent, undecided, unconcerned