Notch filter is not a notch filter?

[Giorgio_Rinolfi]

Its a Pixracer, ESC Dshot 600,1404 motors and 5" for 190g total weight.

I thought i read that anything over about 1000Hz in the main loop leads to instability.

Fortunatly not true! Its only that the telemetry and probably logs don’t works above 1000Hz, master @tridge is working on this and there is a branch where telemetry works already.
Also in the Ardupilot 2019-2020 Roadmap here RoadMap for 2020/2021 — Dev documentation

We could see " 4kHz+ loop rate PIDs"

LOOP RATE higher than 800 and telemetry message issue

Hi all, we are working with small quadcopter with 5" prop with last AC 3.6 , its a lot of time we are working with loop rate at 800 and we clearly found good improvements in overall stabilization performance and flight behaviour in general. We are using also a precise indoor localization system and again setting loop rates higher than 800 bring evident and consistent improvement in position hold and navigation performance. BUT… Passing from 800 to 1200, is better but telemetry message to gr…

P.S.: I’ve fly 2 complete battery few hours ago with mainloop set at 1600, and was top of the top performance to date, no joke. I 'm really temped to try tomorrow at 2400