so anyway i finally got my 4inch running decent but something is off with the RPM filter situation and i cant figure out if im actually making it better or worse every time i mess with it. props are balanced, motors seem fine, ran motor analyzr and nothing jumped out

the problem is theres this mid throttle oscillation thing, its not terrible but you can feel it in the video and it bugs me. ive been following the standard blackbox filtering workflow, looked at the gyro traces and there are these peaks around 180-200hz range. set the notch filters on those and it seemed better for like one pack then came back. running BLHELI_32 ESCs with bidirectional dshot enabled so the RPM filter should be working

genuinely not sure if its a filter issue or if i just need to drop my D term a bit. i feel like ive been chasing this for two weeks and going in circles

check that bidirectional dshot is actually working first before messing with anything else. go into the motors tab in BF configurator and see if you're actually getting erpm telemetry back, theres a little indicator. ive had it silently fail because of a firmware mismatch between BF and BLHELI_32 version and spent days wondering why my RPM filter felt like it was doing nothing

if its actually working then yeah i'd look at D before adding more notch filters. adding notches adds latency and if you pile too many on top of each other youre basically making the flight controller slower to respond which can actually create more oscillation not less. drop D maybe 10-15% from where you are and see what happens before touching filters again

mid throttle oscillations are almost always D related in my experience, ive basically stopped messing with notch filters for that specific symptom. also worth checking your motor temps after a pack ? if one motor is running significantly hotter than the others you might have a bearing starting to go which will show up exactly like this in blackbox even if the motor analyzer didnt catch it