Originally Posted by jjmouris
Note, unless I am mistaking George's firmware uses 16Khz also when the motor is at speed.
It runs at 13kHz, but notably also at start up. So it starts with lots of small pulses to get low power. Castle 1.56 drops the PWM to 1.5 kHz to get low start power with bigger current pulses which are more dangerous when things go wrong. The stock low cost controller starts at 8kHz with the shortest pulse they can manage which is why it is too brutal on 6S.