i got some sentence in tuning_the_ecl_ek chapter
An isolation mount has 6 degrees of freedom, and therefore 6 resonant frequencies. As a general rule, the 6 resonant frequencies of the autopilot on the isolation mount should be above 25Hz to avoid interaction with the autopilot dynamics and below the frequency of the motors.
which is very according with our flight controller anti-vibration modifing experiment
if the anti-vibration is not proper，it very commont to occur a very large 25Hz acclerator noise, that make flight controller very unstable.
the data can be saw here
https://review.px4.io/plot_app?log=a427e94f-e238-4b28-8b16-248ad3de5e75
https://review.px4.io/plot_app?log=7289e37f-38c8-49c8-9e51-615b57725a16
https://review.px4.io/plot_app?log=a97038e5-b1f3-44d6-8657-6bee3761e72d
https://review.px4.io/plot_app?log=21866198-a19b-4a63-bf9d-19caecdb5cc2
the question is how that 25Hz be derivated, and are there any deatail explaniation in theory for that sentence referenced above