The amplitude reduction, and possibly more the frequency change of the WE line, successfully lowered the DARM spectrum in such range and removed some low-frequency pattern that were seen in DARM error signal in time domain; as a double check I tried an additional factor 10 reduction of the lines' amplitudes, but the additional effect is negligible, as the RMS is dominated by the UGF line of DARM itself, which we still have to optimize in the LOW_NOISE_1 confguration. In Figure, blue is the new amplitude, red is 10% of the new amplitude.