View attachment 29326
I measured it a while ago... It isn't causing the 'Sennheiser veil' it does reduce the upper treble but (
without and
with foam) but the small differences can also be caused by a slightly different seating on the fixture. It certainly is within the error of measurement limits as one has to take off the pads, remove the foam, put back the pads and reseat the headphone.
I thought I read somewhere that Sonarworks uses a HATS but found no evidence.
In any case there is no 3kHz peak in their measurements.