In attachment, spectra of the geophones installed in BSC6 and BSC8 are presented with their noise floor are shown in two configurations: 
- ISI damped (only BSC6)
- ISI controlled (L4C blend at 250mHz)

Below 100mHz, in the case of the damping, T240s are in their noise floor for the rotation DOFs and largely above their noise floor for the translation DOFs. GS13s installed on stage 2 are in their noise floor for all DOFs. Consequently, it is difficult to evaluate the actual amplification of the absolute motion of the optical tables between the damped and the isolated configuration. The amplification might be higher than 10, maybe 50?
At EY, when the HEPI-ISI isolation filters are engaged, the optical levers are seeing mainly translation of the test mass and amplification of the "apparent tilt" in pitch and yaw is 50.