Unless someone has actually measured the frequency response, I wouldn’t assume this mod covered 100% of the differences anyway. Sennheiser has several models w

Unless someone has actually measured the frequency response, I wouldn’t assume this mod covered 100% of the differences anyway. Sennheiser has several models where the only difference appears to be a trivial piece of damping material, but the measured difference between the two is substantial. You also can’t get the exact foam piece yourself so mods aren’t possible.