Help needed with SC2 Ultimate awful loud sound

Sometimes my SC2 ultimate does this sound, it is extremely loud, video cant quite capture this.
Anybody knows whats the origin or how I can stop it from doing that?

It is a high frequency oscillation, caused by the motor, QR and wheel resonant frequency being at a particular frequency, and the servo drive filtering (mainly damping, but inertia as well) hitting that frequency. It happens at start in the Safe Torque Mode as that mode has additional damping and friction forced on for safety reasons.

Make sure that you run with latest firmware - the “reduce resonance” checbox on the Hardware settings tab should be enabled. Does it help you at all?

We are working to reduce this via adjusting the internal filtering, but maybe only when the “reduce resonance” is ON, as this issue does not affect all users.

You can use for example a smartphone app such as to find the resonance frequency. it would help if you could measure the frequency for us so we could take this into account for the next firmware version.

Update: videos were shot with TrueDrive 1.0.7.
Looked if there was an update, yes therewas to 1.0.10.
Updated and same results

Yes the reduce resonance checkbox was on.
I will try to use the app and report back.
Any app you can reccomend for iPhone ?

I do not have any iOS devices, so no, but there appears to be several in apple store, for example:

Tried a random app I already had installed apparently.

Does this help you?

frequency of this peak on a lower frequency is of interest - can you try to zoom at this, or try another app?


After trying turning it on and off like 20 times it finally happening again this time with different app:

is there a graph style that would draw a line instead of bars?
Looks like it is around 200 Hz.

198 hz

This resonance is not harmful for the motor/electronics ?

Not harmful, and will be fixed in next firmware update.