Issue: MIDI I/O latency on re-opening a project on Mac

I add a drum plugin to the rack, and allow it to create a MIDI track. (I may have several other drum plugins in the rack)

There is no noticeable latency, I record some drums from my keyboard.

I save and quit.

Some time later I open the project and try to replace drums by playing onto the MIDI track.

There is now a (roughly) 100ms I/O latency delay.

No amount of fiddling with settings will remove it. Every note I play comes out 100ms later. There are NO audio plugins in use at this stage.

I add another drum plugin to the rack, create a new MIDI track and play. There is no latency!

I map the original track to the new instrument, there is a 100ms I/O latency delay on the original track, but NOT the new one. The problem seems to be in the track itself.

Dragging the MIDI parts to the new track does not cause latency issues with the new track.

Save and quit, and at some point, re-opening will reintroduce the latency issue on the new track.

What’s going on?

(I should add that, athough I’ve specified drum plugins, I suspect it happens with other virtual instruments.)

Cubase 11
2010 MacPro 3.46GHz 6-Core Xeon
48GB Ram
OSX 10.14.6 Mojave running from SSD.

Have you added master bus plugins?

Project is corrupted IMO


As stated above: “There are NO audio plugins in use at this stage.” …not on the channel or master bus, or anywhere.

I should add that the MIDI playback on the track isn’t affected; only what’s being played IN to the track from the MIDI input.

At first I thought it was my template, which was created in Cubase 10, which I believe had some MIDI timing issues.

However, it still happens when I create a blank project, with no templates used.


The issue seems to be affected by whether or not I use a drum-map on the track!

Why should the default Steinberg GM drum-map introduce a delay?

It shouldn’t. I use drum maps for SD3 without issues. Also sorry I missed the bit with no plugins. I’m on windows so probably not very helpful anyway.

Does the delay still appear if you use a different drum map, (eg not the GM one?) Just wondering if the map has become corrupted and is altering other settings too?

It’s been that way for ages.
As soon as you chose the drum map you will get a delay while monitoring that track


So, I tried creating a new drum map, and the problem persists.

Drum track - no map: no latency
Drum track - with ANY map: latency around 100 - 120 ms
The latency only affects MIDI coming into the track from the keyboard. Recorded MIDI is not affected.

Add or remove the drum map, and nothing changes. change the active track and then go back (step up and down with the cursor keys) and the latency comes or goes, depending on whether or not the drum map is active.

Yes. This is the behavior that exists since years.