MPC One (also Force) hanging/stuttering when sending midi

Normally only in read mode, but decided to register to get a question (or finding) or myself on this board to see if there are tips or other people experiencing this.

I have an MPC one and when I connect midi gear to it and start tweaking multiple knobs at the same time continuously (after assigning them via midi learn), then the MPC One starts stuttering and hangs for seconds. So for example when pressing a button nothing happens. In worst case also the music stops, the screen flickers (looks like crashing) and get backs to the same screen. After that I can press play and continue again.

So in short; when sending multiple messages looks like the MPC One starts to hang (this also occurs to the Akai Force, although that one doesn't crash but hangs a bit longer and returns to working normally, without stopping music).

I've tested it with multiple controllers:
- Novation Launchcontrol XL (2 knobs already makes live terrible for the MPC One, and it crashes)
- Faderfox EC4 (multiple knobs start making the One stuttering)

But strangely when I used the Arturia Beatstep (the small controller), everything seems to work fine as far as I could see and tested. So it doesn't happen to all controllers, which make me think there might be a solution, setting or whatever to get this solved. I really like the Launch Control, but this way it is unusable as I use multiple controls at the same time often (for example moving faders togethers, or just tweaking more than 1 knobs).

Anyone recognise this? Or could try to test this for yourself? Happy to hear a solution

I did try to turn of tracking and only keep control on at the settings, even kept sync off, but this makes no change.

Without more information, sounds like you might have a midi loop issue. If you know how, I'd suggest going into the MPC midi settings and make sure you aren't both sending and receiving midi information across multiple devices, accidentally causing them to all keep forwarding the same even information to each other and then repeating it.

Try diagnosing a possible feedback loop situation by sending Note-On messages from the Launch Control. I assume it has buttons which can send note-ons? Send the notes also to a synth plugin - do some of the MIDI notes get duplicated? Or could there be too much CC data, and a processing bottleneck of some kind inside the MPC and Force. If you send note-ons rhythmically AND tweak the knobs at the same time, do the note-ons start to get delayed at some point? That could mean that there's too much CC data and it all gets buffered and the buffer grows, until something dumb happens.

NearTao wrote:Without more information, sounds like you might have a midi loop issue. If you know how, I'd suggest going into the MPC midi settings and make sure you aren't both sending and receiving midi information across multiple devices, accidentally causing them to all keep forwarding the same even information to each other and then repeating it.

Could be for sure, although I do monitor the in/out on the MPC and it doesn't show any strange signals, just the onces when I trigger them. But definitely going to check the loop problem in the settings.

HouseWithoutMouse wrote:Try diagnosing a possible feedback loop situation by sending Note-On messages from the Launch Control. I assume it has buttons which can send note-ons? Send the notes also to a synth plugin - do some of the MIDI notes get duplicated? Or could there be too much CC data, and a processing bottleneck of some kind inside the MPC and Force. If you send note-ons rhythmically AND tweak the knobs at the same time, do the note-ons start to get delayed at some point? That could mean that there's too much CC data and it all gets buffered and the buffer grows, until something dumb happens.

I'll check the note on's on their own, didn't do that yet. You're definitely right on the 'looks like too much data' issue, although I don't see midi traffic, but as for example sync info is not shown, maybe other traffic i'm not aware off is also being send. Should maybe put another device in between to monitor what's happening to get insights in the real full midi flow.

What comes to MIDI output, there seem to be quite large buffers. With a few envelope followers routed to a single MIDI out, it's possible to generate more CC data than can be output, and then the buffer starts to grow. The buffer can grow at least half a minute long, I didn't test where the limits are. After stopping the envelope followers, it takes a loooooong time for the data backlog to get be pushed through the MIDI output. Two or three envelope followers are OK, but a fourth one goes over the limit. It would be nice to have a CC thinning setting.