external controller shows too much lag to be usable

I’ve done a lot of experimenting to get my M-Audio Xponent to work, with no success. I’ve read plenty of forum topics and I’m not really surprised, but I thought I would post my experiences either for djay pro support/developers to help, or if anyone else has had the same troubles.

When audio is playing out of the controller, the midi/controller features lag so much they become unusable. I can get every button mapped, and when I move each controller (EQ, xfader, platter) without any audio playing, the onscreen representation is very responsive. When audio is playing (whether 1 or 2 tracks) the on-screen movements (and actual audio) lag behind my actual movements.

I can get 2 tracks playing, cross fade between them, auto sync them, but after that much I/O is happening through the controller, eventfully I can’t even right-click on a track to replace an outgoing track on a deck. I have to stop both audio streams and only then can I choose a new track.

The controller exhibits this lag even when using the computer’s internal sound card. I have to disconnect the controller and do all performance from the internal sound card and keyboard (which is not preferable).

I noticed 2 things to add:

  1. even though I have 1 controller connected, it appears as 2 controllers in MIDI devices
  2. when I hit a button to map a new controller, two notes show up in the assignment window. One of the buttons is the right one, the other is always like C0, or something consistant that isn’t what I actually hit.

This controller works fine with other software, but djay Pro’s spotify integration is so compelling I want to get it to work!! I’m even ok using a splitter cable for split cue instead of a real cue. Would love any help and I can provide more detail/screen shots if necessary. thanks!

(Win 10, ver 1709, build 16299.64, quad 3.1 GHz / 8GB RAM)