I haven't heard the 846, but I wouldn't at all say the IE800 had any more midbass than the K3003. If anything, the K3003's mids don't sound as open or effortless as the IE800's.
Second hand impressions alert: Also, my closest friends here have told me that the SE846's sound is very thick, even in the mids. This is the direct opposite of the drier, more effortless IE800.
Edited by eke2k6 - 4/17/14 at 3:34pm