As far as I remember, those whitening filters for the QPDs of oplevs have not yet been fully well activated, right?? I just wondered if the timing has come to activate them. The noise floor above 2Hz would be due to ADC noise (or... the limited amount of the power got by the QPDs... shot noise is far away) according to my rough check (1602), though the vertical reads seemed "digital counts" there at that time (I did not remember well, sorry).