During warm up, the spindle does not sound right at the highest RPM (24000). I thought the sounds was a much higher squeal pitch, whereas now it is much deeper and louder – as in it made me rush to see if everything was ok. Perhaps it is just me, but I wanted to get your thoughts. I recorded video of it and uploaded to my YouTube channel – the issue occurs right after the 3:53 point.

https://youtu.be/Nrpd2WKXidk?t=230