Possible Internal Vibration Isolation Resonance Around 300 Hz on CUAV V5+?

Hello everyone,

I built a simple vibration excitation setup using a speaker and tested a CUAV V5+ flight controller.

The IMU vibration measurements under sinusoidal excitation are shown below.

From the results, it appears that the internal vibration isolation structure may have a resonance around 300 Hz. Does this interpretation seem reasonable?

I am posting this because the measured response looks somewhat different from the typical frequency response I would expect from a conventional vibration isolation system.

Also, based on the results, it oddly seems as if all IMUs are mounted on the vibration-isolated structure, rather than only some of them. I would appreciate any comments or experiences from anyone who has investigated the internal IMU mounting or vibration characteristics of the CUAV V5+.

Thank you in advance.