Tuning D_min / D_max: damping without hot motors
Dynamic D (D_min/D_max) lets Betaflight adapt damping to the situation — low when it's calm, high when it matters. Set right, you get damping without cooking the motors.
Why dynamic D
Fixed high D damps well but constantly amplifies noise and heats the motors. D_min keeps D low in calm flight (less noise, cooler) and lets it rise to D_max during fast moves (more damping where needed).
Starting values and ratio
Modern defaults are a good start; roughly, D_min sits noticeably below D_max. Too-low D_min can allow propwash and ringing, too-high D_max heats the motors when noise is present — move both in small steps.
D needs clean filters
Because D amplifies noise, good D tuning is only possible after clean filters (RPM filter, D-term lowpass). Otherwise every increase in D heats the motors before it damps.
Balance overshoot vs. heat in the log
The right D is a trade-off between overshoot (too little D) and motor heat (too much D with noise). PIDoctor measures overshoot in the step response and noise in the D-term spectrum — so you find the D that damps without heating.