I got the chance to demo the HD800S today and took along my MHP1000 for a side-by-side comparison. Thought I'd write up my brief impressions as I normally seem to spend far more time on this site talking about music than I do about gear
I should preface my impressions by saying I know it's comparing apples and oranges to a degree, but blame OP for that - I didn't start this thread! I didn't expect night and day differences (I never do) and sure enough there weren't, so no exciting hyperbolic revelations will be forthcoming! I was using a Chord Hugo as DAC/amp and a selection of tracks from a variety of genres including electronic, rock, hip hop, jazz and acoustic.
So...
Putting them on, I noticed how light the S is on the head, and how comfortable - just like the original HD800 in that respect, as you'd expect. Unless you have truly colossal ears, the pads give you space around your ears and then some. The MHP1000 by contrast, is best described as a snug fit, especially if your ears are on the larger side!
In terms of the sound, the first thing that struck me with the S is how smooth the treble response is - every track I threw at them, even some lower quality ones, was reproduced with incredibly smooth treble, without the slightest hint of harshness - but in no way did it feel like detail was compromised either. This was probably the single biggest win over the 1000 for me, which can occasionally get a little hot up top with brighter recordings. However, the 1000 wins out in the bass department, quantity-wise at least - both 'phones extend very well, but there was no denying the visceral impact and slam of the MHP1000 over the HD800S. On certain rock tracks especially, the S seemed a bit lacking in body compared with the 1000 - a little less meat on the bones!
In terms of stereo image width, I'd give it to the S, although the 1000 is no slouch in this department. It's been referred to several times as a closed-back HD800 and with good reason IMO - by far the most out-of-your-head sounding of any closed-back I've tried. The S though, conveys an amazing sense of space for a pair of headphones; the imaging is so on point, especially when listening to Jazz and acoustic music. As far as detail retrieval goes, I would say it's pretty close - both cans are excellent in this regard - but in terms of transparency, I have to give it to the S; the 1000 can occasionally sound a bit congested by comparison.
Overall, the HD800S is mighty impressive and I look forward to auditioning them again. My initial impressions are that they have the edge in several departments including clarity, resolution and accuracy of reproduction, though they do lag behind the 1000 in terms of bass slam; quick-switching between the two really brings that point home.
