Thought it was worth asking the question in light of their last two releases. The HD800 is clearly brighter than the 600/650 (based on general concensus; I'm not in that price range); from reports so far (and Headroom's FR graphs) the 558/598 are similarly brighter than the 555/595. Has Sennheiser been stung by all the "veil" talk, or have they just started noticing the healthy sales of phones like the K702 and DT880?
It's always seemed to me that Sennheiser were one of the few "honest" HP designers in trying to replicate the sound of live acoustic instruments heard from a reasonable distance, as opposed to standing next to the players (since treble dissipates with distance). They were the brand to turn to if you were treble sensitive, maybe the only brand before the advent of Audeze (at a higher price). Now, assuming the 555/595 are discontinued, only the 650 remains in the Sennheiser line for those seeking a more relaxed approach to music--but for how long? If this is Senns new policy, when can we expect the 600/650 series to be replaced by a brighter HD680 or whatever? As a 650 lover, I'm beginning to feel a slight sense of panic, a feeling that I should stock my pantry with a half dozen 650s to tide me over till death.
And I write the above only semi tongue-in-cheek.