I don't think it's a seal issue because even with the largest silicone tips, the sound stays the same. I guess it could perhaps be my ear canal that makes the hole of the spinfits smaller that it should be and thus starts to act as a filter? I am experiencing the opposite indeed. If I take the Sennheiser HD 650 as reference, with the silicone and foam tips it is quite close. But with the spinfits it is way too bassy and dark on the Mojo. Is there a impedance graph available for the Andromeda by any chance?