Bluetooth mouse movements triggering substantial CPU and DSP spikes

Good day everyone,

I’ve been using Cubasis 3 (ver 3.5.1) on my iPad 9 (iPadOS 16.5) for quite awhile now, and even though it’s been a pretty intense love-hate relationship, I always find myself coming back to it.

Upon starting Cubasis up again for the first time in a couple of months, I was welcomed by a bug that would only play back audio to one specific set of headphones, and wouldn’t even play over the internal iPad speakers at full volume.


I updated the iPadOS, restarted my iPad and voila, back to normal. Excitedly, I started a new project and got to work. About 5 tracks into a new project, I began to receive some very strange audio artifacts during playback. I was using the Fab-Filter Pro-Q 3 and the process of elimination to try to discern where the heck all of the crackling and popping was coming from, but to no avail.

After a few days, I finally figured out that the cracking and popping was only happening whilst moving my mouse! I went to check the DSP meter, and sure enough, every time I moved my mouse the DSP and CPU meters would fluctuate wildly.

It’s unfortunate that I didn’t figure it out sooner, but now that I have, I figured I’d report it here just in case the developers are not aware of this bug.

If need be, I am able to share screen recordings of the incident.

Many thanks in advance all,


Hi JJ_R,
This problem is not just related to your Bluetooth mouse, I have the same problem when moving the screen during playback using my finger or pencil, but if you opened one of the tracks and moved your mouse during playback the stuttering stops, so it seems it’s the GI that’s causing the crackles and pops.
Tapping the Follow Cursor tab on the top left of the arrange window will eliminate the stuttering as the cursor follows the song.

Incidentally, the DSP does indeed max out when the stuttering happens, but the CPU hardly moves on my iPad 8th gen (A13 Bionic Chip) and iPad Air 4 (A14 Bionic Chip), your iPad also has the A13 Bionic Chip. If I moved the display with my graphics pad or mouse whilst using Cubase on my Pc, I would still get stuttering, the more tracks I used the worse the stuttering got!
Hope this helps a little bit :slightly_smiling_face:

Hi @JJ_R,

Thanks for your report which has been shared with the team!