I also analyzed the swept-sine OMC acoustic injection data:

2025/04/03 07:03:00 - 07:23:00 Silent run

2025/04/03 7:23:30 - 07:53:30 Speaker injection OMC area
Excitation : K1:PEM-EXCITATION_SR3_RACK_6_EXC
50 - 200 Hz , 1Hz resolution, 10 s in each measurement, 100 cnt

• Fig.1, 2: Spectrograms for each channel
• Fig.3: Microphone -> Strain noise projection using the response function model
• Fig.4 (PDF): Each single frequency injection

The noise excesses in the strain at the double of the injected frequencies are not so large, but they around the injected frequencies are significant.

The projected noise below 150 Hz is close to the current sensitivity. It was not evaluated well in the previous test (klog31563, 2024-11-09) but is well evaluated now, probably thanks to the IFI STM jitter noise that has been hunted.
The projected noise over 200 Hz is also getting closer to the sensitivity than before, but it can be thanks to the sensitivity improvement by the laser power up, because the projected noise level itself looks not changed so much.